Instruction:
Can you generate a brief explanation for the following Python 3 code
def fugacities(self, xs=None, ys=None):
        r'''Helper method for calculating fugacity coefficients for any
        phases present, using either the overall mole fractions for both phases
        or using specified mole fractions for each phase.

        Requires `fugacity_coefficients` to be implemented by each subclassing
        EOS.

        In addition to setting `fugacities_l` and/or `fugacities_g`, this also
        sets the fugacity coefficients `phis_l` and/or `phis_g`.

        .. math::
            \hat \phi_i^g = \frac{\hat f_i^g}{x_i P}

            \hat \phi_i^l = \frac{\hat f_i^l}{x_i P}

        Parameters
        ----------
        xs : list[float], optional
            Liquid-phase mole fractions of each species, [-]
        ys : list[float], optional
            Vapor-phase mole fractions of each species, [-]

        Notes
        -----
        It is helpful to check that `fugacity_coefficients` has been
        implemented correctly using the following expression, from [1]_.

        .. math::
            \ln \hat \phi_i = \left[\frac{\partial (n\log \phi)}{\partial
            n_i}\right]_{T,P,n_j,V_t}

        For reference, several expressions for fugacity of a component are as
        follows, shown in [1]_ and [2]_.

        .. math::
             \ln \hat \phi_i = \int_{0}^P\left(\frac{\hat V_i}
             {RT} - \frac{1}{P}\right)dP

             \ln \hat \phi_i = \int_V^\infty \left[
             \frac{1}{RT}\frac{\partial P}{ \partial n_i}
             - \frac{1}{V}\right] d V - \ln Z

        References
        ----------
        .. [1] Hu, Jiawen, Rong Wang, and Shide Mao. "Some Useful Expressions
           for Deriving Component Fugacity Coefficients from Mixture Fugacity
           Coefficient." Fluid Phase Equilibria 268, no. 1-2 (June 25, 2008):
           7-13. doi:10.1016/j.fluid.2008.03.007.
        .. [2] Walas, Stanley M. Phase Equilibria in Chemical Engineering.
           Butterworth-Heinemann, 1985.
        '''
        if self.phase in ['l', 'l/g']:
            if xs is None:
                xs = self.zs
            self.phis_l = self.fugacity_coefficients(self.Z_l, zs=xs)
            self.fugacities_l = [phi*x*self.P for phi, x in zip(self.phis_l, xs)]
            self.lnphis_l = [log(i) for i in self.phis_l]
        if self.phase in ['g', 'l/g']:
            if ys is None:
                ys = self.zs
            self.phis_g = self.fugacity_coefficients(self.Z_g, zs=ys)
            self.fugacities_g = [phi*y*self.P for phi, y in zip(self.phis_g, ys)]
            self.lnphis_g = [log(i) for i in self.phis_g]

Response: r A method to calculate the fugacity coefficients for any Arc - level entry in the system.


Instruction:
Given the following Python 3 function, write the documentation
def setup_a_alpha_and_derivatives(self, i, T=None):
        r'''Sets `a`, `kappa`, and `Tc` for a specific component before the
        pure-species EOS's `a_alpha_and_derivatives` method is called. Both are
        called by `GCEOSMIX.a_alpha_and_derivatives` for every component.'''
        self.a, self.kappa, self.Tc = self.ais[i], self.kappas[i], self.Tcs[i]

Response: r Sets a kappa and Tc for a specific species.


Instruction:
Here you have a function in Python 3, explain what it does
def setup_a_alpha_and_derivatives(self, i, T=None):
        r'''Sets `a`, `m`, and `Tc` for a specific component before the
        pure-species EOS's `a_alpha_and_derivatives` method is called. Both are
        called by `GCEOSMIX.a_alpha_and_derivatives` for every component.'''
        self.a, self.m, self.Tc = self.ais[i], self.ms[i], self.Tcs[i]

Response:
r Sets a m and Tc for a specific component before the
        pure - species EOS s a_alpha_and_derivatives method is called.


Instruction:
Given the following Python 3 function, write the documentation
def fugacity_coefficients(self, Z, zs):
        r'''Literature formula for calculating fugacity coefficients for each
        species in a mixture. Verified numerically.
        Called by `fugacities` on initialization, or by a solver routine
        which is performing a flash calculation.

        .. math::
            \ln \hat \phi_i = \frac{b_i}{V-b} - \ln\left[Z\left(1
            - \frac{b}{V}\right)\right] - \frac{2\sqrt{aa_i}}{RTV}

        Parameters
        ----------
        Z : float
            Compressibility of the mixture for a desired phase, [-]
        zs : list[float], optional
            List of mole factions, either overall or in a specific phase, [-]

        Returns
        -------
        phis : float
            Fugacity coefficient for each species, [-]

        References
        ----------
        .. [1] Walas, Stanley M. Phase Equilibria in Chemical Engineering.
           Butterworth-Heinemann, 1985.
        '''
        phis = []
        V = Z*R*self.T/self.P
        for i in self.cmps:
            phi = self.bs[i]/(V-self.b) - log(Z*(1. - self.b/V)) - 2.*(self.a_alpha*self.ais[i])**0.5/(R*self.T*V)
            phis.append(exp(phi))
        return phis

Response:
Literature formula for calculating fugacity coefficients for each species in a mixture. Verified numerically. Called by fugacities on initialization and solver routine
 zs is optional and returns a list of lists of fugacity coefficients for each species in a mixture.


Instruction:
Given the following Python 3 function, write the documentation
def cleanup_a_alpha_and_derivatives(self):
        r'''Removes properties set by `setup_a_alpha_and_derivatives`; run by
        `GCEOSMIX.a_alpha_and_derivatives` after `a_alpha` is calculated for
        every component'''
        del(self.a, self.kappa, self.kappa0, self.kappa1, self.Tc)

Response:
r Removes properties set by setup_a_alpha_and_derivatives after a_alpha is calculated for
        every component


Instruction:
Make a summary of the following Python 3 code
def setup_a_alpha_and_derivatives(self, i, T=None):
        r'''Sets `a`, `kappa`, `kappa0`, `kappa1`, `kappa2`, `kappa3` and `Tc`
        for a specific component before the
        pure-species EOS's `a_alpha_and_derivatives` method is called. Both are
        called by `GCEOSMIX.a_alpha_and_derivatives` for every component.'''
        if not hasattr(self, 'kappas'):
            self.kappas = []
            for Tc, kappa0, kappa1, kappa2, kappa3 in zip(self.Tcs, self.kappa0s, self.kappa1s, self.kappa2s, self.kappa3s):
                Tr = T/Tc
                kappa = kappa0 + ((kappa1 + kappa2*(kappa3 - Tr)*(1. - Tr**0.5))*(1. + Tr**0.5)*(0.7 - Tr))
                self.kappas.append(kappa)

        (self.a, self.kappa, self.kappa0, self.kappa1, self.kappa2,
         self.kappa3, self.Tc) = (self.ais[i], self.kappas[i], self.kappa0s[i],
         self.kappa1s[i], self.kappa2s[i], self.kappa3s[i], self.Tcs[i])

Response: r Sets a and kappa for a specific species EOS.


Instruction:
Can you tell what is the following Python 3 function doing
def cleanup_a_alpha_and_derivatives(self):
        r'''Removes properties set by `setup_a_alpha_and_derivatives`; run by
        `GCEOSMIX.a_alpha_and_derivatives` after `a_alpha` is calculated for
        every component'''
        del(self.a, self.kappa, self.kappa0, self.kappa1, self.kappa2, self.kappa3, self.Tc)

Response:
r Removes properties set by setup_a_alpha_and_derivatives after a_alpha is calculated for
        every component


Instruction:
Can you tell what is the following Python 3 function doing
def setup_a_alpha_and_derivatives(self, i, T=None):
        r'''Sets `a`, `omega`, and `Tc` for a specific component before the
        pure-species EOS's `a_alpha_and_derivatives` method is called. Both are
        called by `GCEOSMIX.a_alpha_and_derivatives` for every component.'''
        self.a, self.Tc, self.omega  = self.ais[i], self.Tcs[i], self.omegas[i]

Response:
r Sets a omega Tc and a Tc for a specific component before the
        pure - species EOS s a_alpha_and_derivatives method is called.


Instruction:
Can you generate the documentation for the following Python 3 function
def setup_a_alpha_and_derivatives(self, i, T=None):
        r'''Sets `a`, `S1`, `S2` and `Tc` for a specific component before the
        pure-species EOS's `a_alpha_and_derivatives` method is called. Both are
        called by `GCEOSMIX.a_alpha_and_derivatives` for every component.'''
        self.a, self.Tc, self.S1, self.S2  = self.ais[i], self.Tcs[i], self.S1s[i], self.S2s[i]

Response:
r Sets a S1 S2 and Tc for a specific component before the
        pure - species EOS s a_alpha_and_derivatives method is called.


Instruction:
Explain what the following Python 3 code does
def cleanup_a_alpha_and_derivatives(self):
        r'''Removes properties set by `setup_a_alpha_and_derivatives`; run by
        `GCEOSMIX.a_alpha_and_derivatives` after `a_alpha` is calculated for
        every component'''
        del(self.a, self.Tc, self.S1, self.S2)

Response:
r Removes properties set by setup_a_alpha_and_derivatives after a_alpha is calculated for
        every component


Instruction:
Explain what the following Python 3 code does
def Nicola_original(T, M, Tc, omega, Hfus):
    r'''Estimates the thermal conductivity of a liquid as a function of
    temperature using the CSP method of Nicola [1]_. A  simpler but long
    method claiming high-accuracy and using only statistically significant
    variable following analalysis.

    Requires temperature, molecular weight, critical temperature, acentric
    factor and the heat of vaporization.

    .. math::
        \frac{\lambda}{1 \text{Wm/K}}=-0.5694-0.1436T_r+5.4893\times10^{-10}
        \frac{\Delta_{fus}H}{\text{kmol/J}}+0.0508\omega +
        \left(\frac{1 \text{kg/kmol}}{MW}\right)^{0.0622}

    Parameters
    ----------
    T : float
        Temperature of the fluid [K]
    M : float
        Molecular weight of the fluid [g/mol]
    Tc : float
        Critical temperature of the fluid [K]
    omega : float
        Acentric factor of the fluid [-]
    Hfus : float
        Heat of fusion of the fluid [J/mol]

    Returns
    -------
    kl : float
        Estimated liquid thermal conductivity [W/m/k]

    Notes
    -----
    A weird statistical correlation. Recent and yet to be reviewed.
    This correlation has been superceded by the author's later work.
    Hfus is internally converted to be in J/kmol.

    Examples
    --------
    >>> Nicola_original(300, 142.3, 611.7, 0.49, 201853)
    0.2305018632230984

    References
    ----------
    .. [1] Nicola, Giovanni Di, Eleonora Ciarrocchi, Mariano Pierantozzi, and
        Roman Stryjek. "A New Equation for the Thermal Conductivity of Organic
        Compounds." Journal of Thermal Analysis and Calorimetry 116, no. 1
        (April 1, 2014): 135-40. doi:10.1007/s10973-013-3422-7
    '''
    Tr = T/Tc
    Hfus = Hfus*1000
    return -0.5694 - 0.1436*Tr + 5.4893E-10*Hfus + 0.0508*omega + (1./M)**0.0622

Response: A function of Nicola s original thermal conductivity of a liquid.


Instruction:
How would you explain what the following Python 3 function does
def Nicola(T, M, Tc, Pc, omega):
    r'''Estimates the thermal conductivity of a liquid as a function of
    temperature using the CSP method of [1]_. A statistically derived
    equation using any correlated terms.

    Requires temperature, molecular weight, critical temperature and pressure,
    and acentric factor.

    .. math::
        \frac{\lambda}{0.5147 W/m/K} = -0.2537T_r+\frac{0.0017Pc}{\text{bar}}
        +0.1501 \omega + \left(\frac{1}{MW}\right)^{-0.2999}

    Parameters
    ----------
    T : float
        Temperature of the fluid [K]
    M : float
        Molecular weight of the fluid [g/mol]
    Tc : float
        Critical temperature of the fluid [K]
    Pc : float
        Critical pressure of the fluid [Pa]
    omega : float
        Acentric factor of the fluid [-]

    Returns
    -------
    kl : float
        Estimated liquid thermal conductivity [W/m/k]

    Notes
    -----
    A statistical correlation. A revision of an original correlation.

    Examples
    --------
    >>> Nicola(300, 142.3, 611.7, 2110000.0, 0.49)
    0.10863821554584034

    References
    ----------
    .. [1] Di Nicola, Giovanni, Eleonora Ciarrocchi, Gianluca Coccia, and
       Mariano Pierantozzi. "Correlations of Thermal Conductivity for
       Liquid Refrigerants at Atmospheric Pressure or near Saturation."
       International Journal of Refrigeration. 2014.
       doi:10.1016/j.ijrefrig.2014.06.003
    '''
    Tr = T/Tc
    Pc = Pc/1E5
    return 0.5147*(-0.2537*Tr + 0.0017*Pc + 0.1501*omega + (1./M)**0.2999)

Response: r Estimates the thermal conductivity of a liquid in a statistically derived system.


Instruction:
How would you explain what the following Python 3 function does
def Bahadori_liquid(T, M):
    r'''Estimates the thermal conductivity of parafin liquid hydrocarbons.
    Fits their data well, and is useful as only MW is required.
    X is the Molecular weight, and Y the temperature.

    .. math::
        K = a + bY + CY^2 + dY^3

        a = A_1 + B_1 X + C_1 X^2 + D_1 X^3

        b = A_2 + B_2 X + C_2 X^2 + D_2 X^3

        c = A_3 + B_3 X + C_3 X^2 + D_3 X^3

        d = A_4 + B_4 X + C_4 X^2 + D_4 X^3

    Parameters
    ----------
    T : float
        Temperature of the fluid [K]
    M : float
        Molecular weight of the fluid [g/mol]

    Returns
    -------
    kl : float
        Estimated liquid thermal conductivity [W/m/k]

    Notes
    -----
    The accuracy of this equation has not been reviewed.

    Examples
    --------
    Data point from [1]_.

    >>> Bahadori_liquid(273.15, 170)
    0.14274278108272603

    References
    ----------
    .. [1] Bahadori, Alireza, and Saeid Mokhatab. "Estimating Thermal
       Conductivity of Hydrocarbons." Chemical Engineering 115, no. 13
       (December 2008): 52-54
    '''
    A = [-6.48326E-2, 2.715015E-3, -1.08580E-5, 9.853917E-9]
    B = [1.565612E-2, -1.55833E-4, 5.051114E-7, -4.68030E-10]
    C = [-1.80304E-4, 1.758693E-6, -5.55224E-9, 5.201365E-12]
    D = [5.880443E-7, -5.65898E-9, 1.764384E-11, -1.65944E-14]
    X, Y = M, T
    a = A[0] + B[0]*X + C[0]*X**2 + D[0]*X**3
    b = A[1] + B[1]*X + C[1]*X**2 + D[1]*X**3
    c = A[2] + B[2]*X + C[2]*X**2 + D[2]*X**3
    d = A[3] + B[3]*X + C[3]*X**2 + D[3]*X**3
    return a + b*Y + c*Y**2 + d*Y**3

Response: r Bahadori - Alireza and Saeid Mokhatab.


Instruction:
How would you explain what the following Python 3 function does
def Missenard(T, P, Tc, Pc, kl):
    r'''Adjustes for pressure the thermal conductivity of a liquid using an
    emperical formula based on [1]_, but as given in [2]_.

    .. math::
        \frac{k}{k^*} = 1 + Q P_r^{0.7}

    Parameters
    ----------
    T : float
        Temperature of fluid [K]
    P : float
        Pressure of fluid [Pa]
    Tc: float
        Critical point of fluid [K]
    Pc : float
        Critical pressure of the fluid [Pa]
    kl : float
        Thermal conductivity of liquid at 1 atm or saturation, [W/m/K]

    Returns
    -------
    kl_dense : float
        Thermal conductivity of liquid at P, [W/m/K]

    Notes
    -----
    This equation is entirely dimensionless; all dimensions cancel.
    An interpolation routine is used here from tabulated values of Q.
    The original source has not been reviewed.

    Examples
    --------
    Example from [2]_, toluene; matches.

    >>> Missenard(304., 6330E5, 591.8, 41E5, 0.129)
    0.2198375777069657

    References
    ----------
    .. [1] Missenard, F. A., Thermal Conductivity of Organic Liquids of a
       Series or a Group of Liquids , Rev. Gen.Thermodyn., 101 649 (1970).
    .. [2] Poling, Bruce E. The Properties of Gases and Liquids. 5th edition.
       New York: McGraw-Hill Professional, 2000.
    '''
    Tr = T/Tc
    Pr = P/Pc
    Q = float(Qfunc_Missenard(Pr, Tr))
    return kl*(1. + Q*Pr**0.7)

Response: r Missenard is a simple formula that calculates the thermal conductivity of a liquid at a given temperature at a given pressure at a given temperature at a given critical point.


Instruction:
Given the following Python 3 function, write the documentation
def DIPPR9H(ws, ks):
    r'''Calculates thermal conductivity of a liquid mixture according to
    mixing rules in [1]_ and also in [2]_.

    .. math::
        \lambda_m = \left( \sum_i w_i \lambda_i^{-2}\right)^{-1/2}

    Parameters
    ----------
    ws : float
        Mass fractions of components
    ks : float
        Liquid thermal conductivites of all components, [W/m/K]

    Returns
    -------
    kl : float
        Thermal conductivity of liquid mixture, [W/m/K]

    Notes
    -----
    This equation is entirely dimensionless; all dimensions cancel.
    The example is from [2]_; all results agree.
    The original source has not been reviewed.

    DIPPR Procedure 9H: Method for the Thermal Conductivity of Nonaqueous Liquid Mixtures

    Average deviations of 3%. for 118 nonaqueous systems with 817 data points.
    Max deviation 20%. According to DIPPR.

    Examples
    --------
    >>> DIPPR9H([0.258, 0.742], [0.1692, 0.1528])
    0.15657104706719646

    References
    ----------
    .. [1] Reid, Robert C.; Prausnitz, John M.; Poling, Bruce E. The
       Properties of Gases and Liquids. McGraw-Hill Companies, 1987.
    .. [2] Danner, Ronald P, and Design Institute for Physical Property Data.
       Manual for Predicting Chemical Process Design Data. New York, N.Y, 1982.
    '''
    if not none_and_length_check([ks, ws]):  # check same-length inputs
        raise Exception('Function inputs are incorrect format')
    return sum(ws[i]/ks[i]**2 for i in range(len(ws)))**(-0.5)

Response: r A function that calculates the thermal conductivity of a liquid mixture according to the DIPPR9H formula.


Instruction:
Can you tell what is the following Python 3 function doing
def eli_hanley(T, MW, Tc, Vc, Zc, omega, Cvm):
    r'''Estimates the thermal conductivity of a gas as a function of
    temperature using the reference fluid method of Eli and Hanley [1]_ as
    shown in [2]_.

    .. math::
        \lambda = \lambda^* + \frac{\eta^*}{MW}(1.32)\left(C_v - \frac{3R}{2}\right)

        Tr = \text{min}(Tr, 2)

        \theta = 1 + (\omega-0.011)\left(0.56553 - 0.86276\ln Tr - \frac{0.69852}{Tr}\right)

        \psi = [1 + (\omega - 0.011)(0.38560 - 1.1617\ln Tr)]\frac{0.288}{Z_c}

        f = \frac{T_c}{190.4}\theta

        h = \frac{V_c}{9.92E-5}\psi

        T_0 = T/f

        \eta_0^*(T_0)= \sum_{n=1}^9 C_n T_0^{(n-4)/3}

        \theta_0 = 1944 \eta_0

        \lambda^* = \lambda_0 H

        \eta^* = \eta^*_0 H \frac{MW}{16.04}

        H = \left(\frac{16.04}{MW}\right)^{0.5}f^{0.5}/h^{2/3}

    Parameters
    ----------
    T : float
        Temperature of the gas [K]
    MW : float
        Molecular weight of the gas [g/mol]
    Tc : float
        Critical temperature of the gas [K]
    Vc : float
        Critical volume of the gas [m^3/mol]
    Zc : float
        Critical compressibility of the gas []
    omega : float
        Acentric factor of the gas [-]
    Cvm : float
        Molar contant volume heat capacity of the gas [J/mol/K]

    Returns
    -------
    kg : float
        Estimated gas thermal conductivity [W/m/k]

    Notes
    -----
    Reference fluid is Methane.
    MW internally converted to kg/g-mol.

    Examples
    --------
    2-methylbutane at low pressure, 373.15 K. Mathes calculation in [2]_.

    >>> eli_hanley(T=373.15, MW=72.151, Tc=460.4, Vc=3.06E-4, Zc=0.267,
    ... omega=0.227, Cvm=135.9)
    0.02247951789135337

    References
    ----------
    .. [1] Ely, James F., and H. J. M. Hanley. "Prediction of Transport
       Properties. 2. Thermal Conductivity of Pure Fluids and Mixtures."
       Industrial & Engineering Chemistry Fundamentals 22, no. 1 (February 1,
       1983): 90-97. doi:10.1021/i100009a016.
    .. [2] Reid, Robert C.; Prausnitz, John M.; Poling, Bruce E.
       Properties of Gases and Liquids. McGraw-Hill Companies, 1987.
    '''
    Cs = [2.907741307E6, -3.312874033E6, 1.608101838E6, -4.331904871E5,
          7.062481330E4, -7.116620750E3, 4.325174400E2, -1.445911210E1, 2.037119479E-1]

    Tr = T/Tc
    if Tr > 2: Tr = 2
    theta = 1 + (omega - 0.011)*(0.56553 - 0.86276*log(Tr) - 0.69852/Tr)
    psi = (1 + (omega-0.011)*(0.38560 - 1.1617*log(Tr)))*0.288/Zc
    f = Tc/190.4*theta
    h = Vc/9.92E-5*psi
    T0 = T/f
    eta0 = 1E-7*sum([Ci*T0**((i+1. - 4.)/3.) for i, Ci in enumerate(Cs)])
    k0 = 1944*eta0

    H = (16.04/MW)**0.5*f**0.5*h**(-2/3.)
    etas = eta0*H*MW/16.04
    ks = k0*H
    return ks + etas/(MW/1000.)*1.32*(Cvm - 1.5*R)

Response: Estimate the thermal conductivity of a given gas using the reference fluid method of Eli and Hanley.


Instruction:
Explain what the following Python 3 code does
def Gharagheizi_gas(T, MW, Tb, Pc, omega):
    r'''Estimates the thermal conductivity of a gas as a function of
    temperature using the CSP method of Gharagheizi [1]_. A  convoluted
    method claiming high-accuracy and using only statistically significant
    variable following analalysis.

    Requires temperature, molecular weight, boiling temperature and critical
    pressure and acentric factor.

    .. math::
        k = 7.9505\times 10^{-4} + 3.989\times 10^{-5} T
        -5.419\times 10^-5 M + 3.989\times 10^{-5} A

       A = \frac{\left(2\omega + T - \frac{(2\omega + 3.2825)T}{T_b} + 3.2825\right)}{0.1MP_cT}
        \times (3.9752\omega + 0.1 P_c + 1.9876B + 6.5243)^2

    Parameters
    ----------
    T : float
        Temperature of the fluid [K]
    MW: float
        Molecular weight of the fluid [g/mol]
    Tb : float
        Boiling temperature of the fluid [K]
    Pc : float
        Critical pressure of the fluid [Pa]
    omega : float
        Acentric factor of the fluid [-]

    Returns
    -------
    kg : float
        Estimated gas thermal conductivity [W/m/k]

    Notes
    -----
    Pressure is internally converted into 10*kPa but author used correlation with
    kPa; overall, errors have been corrected in the presentation of the formula.

    This equation was derived with 15927 points and 1574 compounds.
    Example value from [1]_ is the first point in the supportinf info, for CH4.

    Examples
    --------
    >>> Gharagheizi_gas(580., 16.04246, 111.66, 4599000.0, 0.0115478000)
    0.09594861261873211

    References
    ----------
    .. [1] Gharagheizi, Farhad, Poorandokht Ilani-Kashkouli, Mehdi Sattari,
       Amir H. Mohammadi, Deresh Ramjugernath, and Dominique Richon.
       "Development of a General Model for Determination of Thermal
       Conductivity of Liquid Chemical Compounds at Atmospheric Pressure."
       AIChE Journal 59, no. 5 (May 1, 2013): 1702-8. doi:10.1002/aic.13938
    '''
    Pc = Pc/1E4
    B = T + (2.*omega + 2.*T - 2.*T*(2.*omega + 3.2825)/Tb + 3.2825)/(2*omega + T - T*(2*omega+3.2825)/Tb + 3.2825) - T*(2*omega+3.2825)/Tb
    A = (2*omega + T - T*(2*omega + 3.2825)/Tb + 3.2825)/(0.1*MW*Pc*T) * (3.9752*omega + 0.1*Pc + 1.9876*B + 6.5243)**2
    return 7.9505E-4 + 3.989E-5*T - 5.419E-5*MW + 3.989E-5*A

Response: r Estimates the thermal conductivity of a given resource in a given time - domain basis using the CSP method of Gharagheizi.


Instruction:
How would you explain what the following Python 3 function does
def Bahadori_gas(T, MW):
    r'''Estimates the thermal conductivity of hydrocarbons gases at low P.
    Fits their data well, and is useful as only MW is required.
    Y is the Molecular weight, and X the temperature.

    .. math::
        K = a + bY + CY^2 + dY^3

        a = A_1 + B_1 X + C_1 X^2 + D_1 X^3

        b = A_2 + B_2 X + C_2 X^2 + D_2 X^3

        c = A_3 + B_3 X + C_3 X^2 + D_3 X^3

        d = A_4 + B_4 X + C_4 X^2 + D_4 X^3

    Parameters
    ----------
    T : float
        Temperature of the gas [K]
    MW : float
        Molecular weight of the gas [g/mol]

    Returns
    -------
    kg : float
        Estimated gas thermal conductivity [W/m/k]

    Notes
    -----
    The accuracy of this equation has not been reviewed.

    Examples
    --------
    >>> Bahadori_gas(40+273.15, 20) # Point from article
    0.031968165337873326

    References
    ----------
    .. [1] Bahadori, Alireza, and Saeid Mokhatab. "Estimating Thermal
       Conductivity of Hydrocarbons." Chemical Engineering 115, no. 13
       (December 2008): 52-54
    '''
    A = [4.3931323468E-1, -3.88001122207E-2, 9.28616040136E-4, -6.57828995724E-6]
    B = [-2.9624238519E-3, 2.67956145820E-4, -6.40171884139E-6, 4.48579040207E-8]
    C = [7.54249790107E-6, -6.46636219509E-7, 1.5124510261E-8, -1.0376480449E-10]
    D = [-6.0988433456E-9, 5.20752132076E-10, -1.19425545729E-11, 8.0136464085E-14]
    X, Y = T, MW
    a = A[0] + B[0]*X + C[0]*X**2 + D[0]*X**3
    b = A[1] + B[1]*X + C[1]*X**2 + D[1]*X**3
    c = A[2] + B[2]*X + C[2]*X**2 + D[2]*X**3
    d = A[3] + B[3]*X + C[3]*X**2 + D[3]*X**3
    return a + b*Y + c*Y**2 + d*Y**3

Response: r Estimates the thermal conductivity of Hydrocarbons at low P.


Instruction:
Can you generate the documentation for the following Python 3 function
def stiel_thodos_dense(T, MW, Tc, Pc, Vc, Zc, Vm, kg):
    r'''Estimates the thermal conductivity of a gas at high pressure as a
    function of temperature using difference method of Stiel and Thodos [1]_
    as shown in [2]_.

    if \rho_r < 0.5:

    .. math::
        (\lambda-\lambda^\circ)\Gamma Z_c^5=1.22\times 10^{-2} [\exp(0.535 \rho_r)-1]

    if 0.5 < \rho_r < 2.0:

    .. math::
        (\lambda-\lambda^\circ)\Gamma Z_c^5=1.22\times 10^{-2} [\exp(0.535 \rho_r)-1]

    if 2 < \rho_r < 2.8:

    .. math::
        (\lambda-\lambda^\circ)\Gamma Z_c^5=1.22\times 10^{-2} [\exp(0.535 \rho_r)-1]

        \Gamma = 210 \left(\frac{T_cMW^3}{P_c^4}\right)^{1/6}

    Parameters
    ----------
    T : float
        Temperature of the gas [K]
    MW : float
        Molecular weight of the gas [g/mol]
    Tc : float
        Critical temperature of the gas [K]
    Pc : float
        Critical pressure of the gas [Pa]
    Vc : float
        Critical volume of the gas [m^3/mol]
    Zc : float
        Critical compressibility of the gas [-]
    Vm : float
        Molar volume of the gas at T and P [m^3/mol]
    kg : float
        Low-pressure gas thermal conductivity [W/m/k]

    Returns
    -------
    kg : float
        Estimated dense gas thermal conductivity [W/m/k]

    Notes
    -----
    Pc is internally converted to bar.

    Examples
    --------
    >>> stiel_thodos_dense(T=378.15, MW=44.013, Tc=309.6, Pc=72.4E5,
    ... Vc=97.4E-6, Zc=0.274, Vm=144E-6, kg=2.34E-2)
    0.041245574404863684

    References
    ----------
    .. [1] Stiel, Leonard I., and George Thodos. "The Thermal Conductivity of
       Nonpolar Substances in the Dense Gaseous and Liquid Regions." AIChE
       Journal 10, no. 1 (January 1, 1964): 26-30. doi:10.1002/aic.690100114.
    .. [2] Reid, Robert C.; Prausnitz, John M.; Poling, Bruce E.
       Properties of Gases and Liquids. McGraw-Hill Companies, 1987.
    '''
    gamma = 210*(Tc*MW**3./(Pc/1E5)**4)**(1/6.)
    rhor = Vc/Vm
    if rhor < 0.5:
        term = 1.22E-2*(exp(0.535*rhor) - 1.)
    elif rhor < 2:
        term = 1.14E-2*(exp(0.67*rhor) - 1.069)
    else:
        # Technically only up to 2.8
        term = 2.60E-3*(exp(1.155*rhor) + 2.016)
    diff = term/Zc**5/gamma
    kg = kg + diff
    return kg

Response: r Estimates the thermal conductivity of a given gas at high pressure using difference method of Stiel and Thodos.


Instruction:
Given the following Python 3 function, write the documentation
def chung_dense(T, MW, Tc, Vc, omega, Cvm, Vm, mu, dipole, association=0):
    r'''Estimates the thermal conductivity of a gas at high pressure as a
    function of temperature using the reference fluid method of
    Chung [1]_ as shown in [2]_.

    .. math::
        \lambda = \frac{31.2 \eta^\circ \Psi}{M'}(G_2^{-1} + B_6 y)+qB_7y^2T_r^{1/2}G_2

        \Psi = 1 + \alpha \left\{[0.215+0.28288\alpha-1.061\beta+0.26665Z]/
        [0.6366+\beta Z + 1.061 \alpha \beta]\right\}

        \alpha = \frac{C_v}{R}-1.5

        \beta = 0.7862-0.7109\omega + 1.3168\omega^2

        Z=2+10.5T_r^2

        q = 3.586\times 10^{-3} (T_c/M')^{1/2}/V_c^{2/3}

        y = \frac{V_c}{6V}

        G_1 = \frac{1-0.5y}{(1-y)^3}

        G_2 = \frac{(B_1/y)[1-\exp(-B_4y)]+ B_2G_1\exp(B_5y) + B_3G_1}
        {B_1B_4 + B_2 + B_3}

        B_i = a_i + b_i \omega + c_i \mu_r^4 + d_i \kappa

    Parameters
    ----------
    T : float
        Temperature of the gas [K]
    MW : float
        Molecular weight of the gas [g/mol]
    Tc : float
        Critical temperature of the gas [K]
    Vc : float
        Critical volume of the gas [m^3/mol]
    omega : float
        Acentric factor of the gas [-]
    Cvm : float
        Molar contant volume heat capacity of the gas [J/mol/K]
    Vm : float
        Molar volume of the gas at T and P [m^3/mol]
    mu : float
        Low-pressure gas viscosity [Pa*S]
    dipole : float
        Dipole moment [debye]
    association : float, optional
        Association factor [-]

    Returns
    -------
    kg : float
        Estimated dense gas thermal conductivity [W/m/k]

    Notes
    -----
    MW internally converted to kg/g-mol.
    Vm internally converted to mL/mol.
    [1]_ is not the latest form as presented in [1]_.
    Association factor is assumed 0. Relates to the polarity of the gas.

    Coefficients as follows:
    ais = [2.4166E+0, -5.0924E-1, 6.6107E+0, 1.4543E+1, 7.9274E-1, -5.8634E+0, 9.1089E+1]

    bis = [7.4824E-1, -1.5094E+0, 5.6207E+0, -8.9139E+0, 8.2019E-1, 1.2801E+1, 1.2811E+2]

    cis = [-9.1858E-1, -4.9991E+1, 6.4760E+1, -5.6379E+0, -6.9369E-1, 9.5893E+0, -5.4217E+1]

    dis = [1.2172E+2, 6.9983E+1, 2.7039E+1, 7.4344E+1, 6.3173E+0, 6.5529E+1, 5.2381E+2]

    Examples
    --------
    >>> chung_dense(T=473., MW=42.081, Tc=364.9, Vc=184.6E-6, omega=0.142,
    ... Cvm=82.67, Vm=172.1E-6, mu=134E-7, dipole=0.4)
    0.06160570379787278

    References
    ----------
    .. [1] Chung, Ting Horng, Mohammad Ajlan, Lloyd L. Lee, and Kenneth E.
       Starling. "Generalized Multiparameter Correlation for Nonpolar and Polar
       Fluid Transport Properties." Industrial & Engineering Chemistry Research
       27, no. 4 (April 1, 1988): 671-79. doi:10.1021/ie00076a024.
    .. [2] Poling, Bruce E. The Properties of Gases and Liquids. 5th edition.
       New York: McGraw-Hill Professional, 2000.
    '''
    ais = [2.4166E+0, -5.0924E-1, 6.6107E+0, 1.4543E+1, 7.9274E-1, -5.8634E+0, 9.1089E+1]
    bis = [7.4824E-1, -1.5094E+0, 5.6207E+0, -8.9139E+0, 8.2019E-1, 1.2801E+1, 1.2811E+2]
    cis = [-9.1858E-1, -4.9991E+1, 6.4760E+1, -5.6379E+0, -6.9369E-1, 9.5893E+0, -5.4217E+1]
    dis = [1.2172E+2, 6.9983E+1, 2.7039E+1, 7.4344E+1, 6.3173E+0, 6.5529E+1, 5.2381E+2]
    Tr = T/Tc
    mur = 131.3*dipole/(Vc*1E6*Tc)**0.5

    # From Chung Method
    alpha = Cvm/R - 1.5
    beta = 0.7862 - 0.7109*omega + 1.3168*omega**2
    Z = 2 + 10.5*(T/Tc)**2
    psi = 1 + alpha*((0.215 + 0.28288*alpha - 1.061*beta + 0.26665*Z)/(0.6366 + beta*Z + 1.061*alpha*beta))

    y = Vc/(6*Vm)
    B1, B2, B3, B4, B5, B6, B7 = [ais[i] + bis[i]*omega + cis[i]*mur**4 + dis[i]*association for i in range(7)]
    G1 = (1 - 0.5*y)/(1. - y)**3
    G2 = (B1/y*(1 - exp(-B4*y)) + B2*G1*exp(B5*y) + B3*G1)/(B1*B4 + B2 + B3)
    q = 3.586E-3*(Tc/(MW/1000.))**0.5/(Vc*1E6)**(2/3.)
    return 31.2*mu*psi/(MW/1000.)*(G2**-1 + B6*y) + q*B7*y**2*Tr**0.5*G2

Response: Chung - Dense Thermal Conductivity of a system in a single phase.


Instruction:
How would you explain what the following Python 3 function does
def calculate(self, T, method):
        r'''Method to calculate low-pressure liquid thermal conductivity at
        tempearture `T` with a given method.

        This method has no exception handling; see `T_dependent_property`
        for that.

        Parameters
        ----------
        T : float
            Temperature of the liquid, [K]
        method : str
            Name of the method to use

        Returns
        -------
        kl : float
            Thermal conductivity of the liquid at T and a low pressure, [W/m/K]
        '''
        if method == SHEFFY_JOHNSON:
            kl = Sheffy_Johnson(T, self.MW, self.Tm)
        elif method == SATO_RIEDEL:
            kl = Sato_Riedel(T, self.MW, self.Tb, self.Tc)
        elif method == GHARAGHEIZI_L:
            kl = Gharagheizi_liquid(T, self.MW, self.Tb, self.Pc, self.omega)
        elif method == NICOLA:
            kl = Nicola(T, self.MW, self.Tc, self.Pc, self.omega)
        elif method == NICOLA_ORIGINAL:
            kl = Nicola_original(T, self.MW, self.Tc, self.omega, self.Hfus)
        elif method == LAKSHMI_PRASAD:
            kl = Lakshmi_Prasad(T, self.MW)
        elif method == BAHADORI_L:
            kl = Bahadori_liquid(T, self.MW)
        elif method == DIPPR_PERRY_8E:
            kl = EQ100(T, *self.Perrys2_315_coeffs)
        elif method == VDI_PPDS:
            kl = horner(self.VDI_PPDS_coeffs, T)
        elif method == COOLPROP:
            kl = CoolProp_T_dependent_property(T, self.CASRN, 'L', 'l')
        elif method in self.tabular_data:
            kl = self.interpolate(T, method)
        return kl

Response: r This method calculates the low - pressure liquid thermal conductivity at a given temperature at a given method.


Instruction:
Here you have a function in Python 3, explain what it does
def calculate(self, T, P, zs, ws, method):
        r'''Method to calculate thermal conductivity of a liquid mixture at
        temperature `T`, pressure `P`, mole fractions `zs` and weight fractions
        `ws` with a given method.

        This method has no exception handling; see `mixture_property`
        for that.

        Parameters
        ----------
        T : float
            Temperature at which to calculate the property, [K]
        P : float
            Pressure at which to calculate the property, [Pa]
        zs : list[float]
            Mole fractions of all species in the mixture, [-]
        ws : list[float]
            Weight fractions of all species in the mixture, [-]
        method : str
            Name of the method to use

        Returns
        -------
        k : float
            Thermal conductivity of the liquid mixture, [W/m/K]
        '''
        if method == SIMPLE:
            ks = [i(T, P) for i in self.ThermalConductivityLiquids]
            return mixing_simple(zs, ks)
        elif method == DIPPR_9H:
            ks = [i(T, P) for i in self.ThermalConductivityLiquids]
            return DIPPR9H(ws, ks)
        elif method == FILIPPOV:
            ks = [i(T, P) for i in self.ThermalConductivityLiquids]
            return Filippov(ws, ks)
        elif method == MAGOMEDOV:
            k_w = self.ThermalConductivityLiquids[self.index_w](T, P)
            ws = list(ws) ; ws.pop(self.index_w)
            return thermal_conductivity_Magomedov(T, P, ws, self.wCASs, k_w)
        else:
            raise Exception('Method not valid')

Response:
r Calculates the thermal conductivity of a liquid mixture at
 temperature pressure mole fractions and weight fractions of all species in the mixture at
 zs and ws.


Instruction:
Can you generate a brief explanation for the following Python 3 code
def load_all_methods(self):
        r'''Method which picks out coefficients for the specified chemical
        from the various dictionaries and DataFrames storing it. All data is
        stored as attributes. This method also sets :obj:`Tmin`, :obj:`Tmax`,
        :obj:`all_methods` and obj:`all_methods_P` as a set of methods for
        which the data exists for.

        Called on initialization only. See the source code for the variables at
        which the coefficients are stored. The coefficients can safely be
        altered once the class is initialized. This method can be called again
        to reset the parameters.
        '''
        methods, methods_P = [], []
        Tmins, Tmaxs = [], []
        if self.CASRN in _VDISaturationDict:
            methods.append(VDI_TABULAR)
            Ts, props = VDI_tabular_data(self.CASRN, 'K (g)')
            self.VDI_Tmin = Ts[0]
            self.VDI_Tmax = Ts[-1]
            self.tabular_data[VDI_TABULAR] = (Ts, props)
            Tmins.append(self.VDI_Tmin); Tmaxs.append(self.VDI_Tmax)
        if has_CoolProp and self.CASRN in coolprop_dict:
            methods.append(COOLPROP); methods_P.append(COOLPROP)
            self.CP_f = coolprop_fluids[self.CASRN]
            Tmins.append(self.CP_f.Tmin); Tmaxs.append(self.CP_f.Tc)
        if self.CASRN in Perrys2_314.index:
            methods.append(DIPPR_PERRY_8E)
            _, C1, C2, C3, C4, self.Perrys2_314_Tmin, self.Perrys2_314_Tmax = _Perrys2_314_values[Perrys2_314.index.get_loc(self.CASRN)].tolist()
            self.Perrys2_314_coeffs = [C1, C2, C3, C4]
            Tmins.append(self.Perrys2_314_Tmin); Tmaxs.append(self.Perrys2_314_Tmax)
        if self.CASRN in VDI_PPDS_10.index:
            _,  A, B, C, D, E = _VDI_PPDS_10_values[VDI_PPDS_10.index.get_loc(self.CASRN)].tolist()
            self.VDI_PPDS_coeffs = [A, B, C, D, E]
            self.VDI_PPDS_coeffs.reverse()
            methods.append(VDI_PPDS)
        if all((self.MW, self.Tb, self.Pc, self.omega)):
            methods.append(GHARAGHEIZI_G)
            # Turns negative at low T; do not set Tmin
            Tmaxs.append(3000)
        if all((self.Cvgm, self.mug, self.MW, self.Tc)):
            methods.append(DIPPR_9B)
            Tmins.append(0.01); Tmaxs.append(1E4)  # No limit here
        if all((self.Cvgm, self.mug, self.MW, self.Tc, self.omega)):
            methods.append(CHUNG)
            Tmins.append(0.01); Tmaxs.append(1E4)  # No limit
        if all((self.Cvgm, self.MW, self.Tc, self.Vc, self.Zc, self.omega)):
            methods.append(ELI_HANLEY)
            Tmaxs.append(1E4)  # Numeric error at low T
        if all((self.Cvgm, self.mug, self.MW)):
            methods.append(EUCKEN_MOD)
            methods.append(EUCKEN)
            Tmins.append(0.01); Tmaxs.append(1E4)  # No limits
        if self.MW:
            methods.append(BAHADORI_G)
            # Terrible method, so don't set methods
        if all([self.MW, self.Tc, self.Vc, self.Zc, self.omega]):
            methods_P.append(ELI_HANLEY_DENSE)
        if all([self.MW, self.Tc, self.Vc, self.omega, self.dipole]):
            methods_P.append(CHUNG_DENSE)
        if all([self.MW, self.Tc, self.Pc, self.Vc, self.Zc]):
            methods_P.append(STIEL_THODOS_DENSE)
        self.all_methods = set(methods)
        self.all_methods_P = set(methods_P)
        if Tmins and Tmaxs:
            self.Tmin, self.Tmax = min(Tmins), max(Tmaxs)

Response: r This method loads all methods for the specified chemicalicalCOOKIE.


Instruction:
Make a summary of the following Python 3 code
def calculate(self, T, method):
        r'''Method to calculate low-pressure gas thermal conductivity at
        tempearture `T` with a given method.

        This method has no exception handling; see `T_dependent_property`
        for that.

        Parameters
        ----------
        T : float
            Temperature of the gas, [K]
        method : str
            Name of the method to use

        Returns
        -------
        kg : float
            Thermal conductivity of the gas at T and a low pressure, [W/m/K]
        '''
        if method == GHARAGHEIZI_G:
            kg = Gharagheizi_gas(T, self.MW, self.Tb, self.Pc, self.omega)
        elif method == DIPPR_9B:
            Cvgm = self.Cvgm(T) if hasattr(self.Cvgm, '__call__') else self.Cvgm
            mug = self.mug(T) if hasattr(self.mug, '__call__') else self.mug
            kg = DIPPR9B(T, self.MW, Cvgm, mug, self.Tc)
        elif method == CHUNG:
            Cvgm = self.Cvgm(T) if hasattr(self.Cvgm, '__call__') else self.Cvgm
            mug = self.mug(T) if hasattr(self.mug, '__call__') else self.mug
            kg = Chung(T, self.MW, self.Tc, self.omega, Cvgm, mug)
        elif method == ELI_HANLEY:
            Cvgm = self.Cvgm(T) if hasattr(self.Cvgm, '__call__') else self.Cvgm
            kg = eli_hanley(T, self.MW, self.Tc, self.Vc, self.Zc, self.omega, Cvgm)
        elif method == EUCKEN_MOD:
            Cvgm = self.Cvgm(T) if hasattr(self.Cvgm, '__call__') else self.Cvgm
            mug = self.mug(T) if hasattr(self.mug, '__call__') else self.mug
            kg = Eucken_modified(self.MW, Cvgm, mug)
        elif method == EUCKEN:
            Cvgm = self.Cvgm(T) if hasattr(self.Cvgm, '__call__') else self.Cvgm
            mug = self.mug(T) if hasattr(self.mug, '__call__') else self.mug
            kg = Eucken(self.MW, Cvgm, mug)
        elif method == DIPPR_PERRY_8E:
            kg = EQ102(T, *self.Perrys2_314_coeffs)
        elif method == VDI_PPDS:
            kg = horner(self.VDI_PPDS_coeffs, T)
        elif method == BAHADORI_G:
            kg = Bahadori_gas(T, self.MW)
        elif method == COOLPROP:
            kg = CoolProp_T_dependent_property(T, self.CASRN, 'L', 'g')
        elif method in self.tabular_data:
            kg = self.interpolate(T, method)
        return kg

Response: r Method to calculate the low - pressure thermal conductivity at a given temperature.


Instruction:
How would you explain what the following Python 3 function does
def calculate(self, T, P, zs, ws, method):
        r'''Method to calculate thermal conductivity of a gas mixture at
        temperature `T`, pressure `P`, mole fractions `zs` and weight fractions
        `ws` with a given method.

        This method has no exception handling; see `mixture_property`
        for that.

        Parameters
        ----------
        T : float
            Temperature at which to calculate the property, [K]
        P : float
            Pressure at which to calculate the property, [Pa]
        zs : list[float]
            Mole fractions of all species in the mixture, [-]
        ws : list[float]
            Weight fractions of all species in the mixture, [-]
        method : str
            Name of the method to use

        Returns
        -------
        kg : float
            Thermal conductivity of gas mixture, [W/m/K]
        '''
        if method == SIMPLE:
            ks = [i(T, P) for i in self.ThermalConductivityGases]
            return mixing_simple(zs, ks)
        elif method == LINDSAY_BROMLEY:
            ks = [i(T, P) for i in self.ThermalConductivityGases]
            mus = [i(T, P) for i in self.ViscosityGases]
            return Lindsay_Bromley(T=T, ys=zs, ks=ks, mus=mus, Tbs=self.Tbs, MWs=self.MWs)
        else:
            raise Exception('Method not valid')

Response:
Method to calculate thermal conductivity of a gas mixture at
 temperature pressure mole fractions and weight fractions of all species in the mixture at these times.


Instruction:
Given the following Python 3 function, write the documentation
def atom_fractions(atoms):
    r'''Calculates the atomic fractions of each element in a compound,
    given a dictionary of its atoms and their counts, in the format
    {symbol: count}.

    .. math::
        a_i =  \frac{n_i}{\sum_i n_i}

    Parameters
    ----------
    atoms : dict
        dictionary of counts of individual atoms, indexed by symbol with
        proper capitalization, [-]

    Returns
    -------
    afracs : dict
        dictionary of atomic fractions of individual atoms, indexed by symbol
        with proper capitalization, [-]

    Notes
    -----
    No actual data on the elements is used, so incorrect or custom compounds
    would not raise an error.

    Examples
    --------
    >>> atom_fractions({'H': 12, 'C': 20, 'O': 5})
    {'H': 0.32432432432432434, 'C': 0.5405405405405406, 'O': 0.13513513513513514}

    References
    ----------
    .. [1] RDKit: Open-source cheminformatics; http://www.rdkit.org
    '''
    count = sum(atoms.values())
    afracs = {}
    for i in atoms:
        afracs[i] = atoms[i]/count
    return afracs

Response: r Returns the atomic fractions of each element in a compound.


Instruction:
Can you generate a brief explanation for the following Python 3 code
def similarity_variable(atoms, MW=None):
    r'''Calculates the similarity variable of an compound, as defined in [1]_.
    Currently only applied for certain heat capacity estimation routines.

    .. math::
        \alpha = \frac{N}{MW} = \frac{\sum_i n_i}{\sum_i n_i MW_i}

    Parameters
    ----------
    atoms : dict
        dictionary of counts of individual atoms, indexed by symbol with
        proper capitalization, [-]
    MW : float, optional
        Molecular weight, [g/mol]

    Returns
    -------
    similarity_variable : float
        Similarity variable as defined in [1]_, [mol/g]

    Notes
    -----
    Molecular weight is optional, but speeds up the calculation slightly. It
    is calculated using the function `molecular_weight` if not specified.

    Examples
    --------
    >>> similarity_variable({'H': 32, 'C': 15})
    0.2212654140784498

    References
    ----------
    .. [1] Laštovka, Václav, Nasser Sallamie, and John M. Shaw. "A Similarity
       Variable for Estimating the Heat Capacity of Solid Organic Compounds:
       Part I. Fundamentals." Fluid Phase Equilibria 268, no. 1-2
       (June 25, 2008): 51-60. doi:10.1016/j.fluid.2008.03.019.
    '''
    if not MW:
        MW = molecular_weight(atoms)
    return sum(atoms.values())/MW

Response: r Calculates the similarity variable of an object.


Instruction:
Here you have a function in Python 3, explain what it does
def simple_formula_parser(formula):
    r'''Basic formula parser, primarily for obtaining element counts from
    formulas as formated in PubChem. Handles formulas with integer counts,
    but no brackets, no hydrates, no charges, no isotopes, and no group
    multipliers.

    Strips charges from the end of a formula first. Accepts repeated chemical
    units. Performs no sanity checking that elements are actually elements.
    As it uses regular expressions for matching, errors are mostly just ignored.

    Parameters
    ----------
    formula : str
        Formula string, very simply formats only.

    Returns
    -------
    atoms : dict
        dictionary of counts of individual atoms, indexed by symbol with
        proper capitalization, [-]

    Notes
    -----
    Inspiration taken from the thermopyl project, at
    https://github.com/choderalab/thermopyl.

    Examples
    --------
    >>> simple_formula_parser('CO2')
    {'C': 1, 'O': 2}
    '''
    formula = formula.split('+')[0].split('-')[0]
    groups = _formula_p1.split(formula)[1::2]
    cnt = Counter()
    for group in groups:
        ele, count = _formula_p2.split(group)[1:]
        cnt[ele] += int(count) if count.isdigit() else 1
    return dict(cnt)

Response: Basic formula parser primarily for obtaining element counts from a single formula.


Instruction:
Given the following Python 3 function, write the documentation
def nested_formula_parser(formula, check=True):
    r'''Improved formula parser which handles braces and their multipliers,
    as well as rational element counts.

    Strips charges from the end of a formula first. Accepts repeated chemical
    units. Performs no sanity checking that elements are actually elements.
    As it uses regular expressions for matching, errors are mostly just ignored.

    Parameters
    ----------
    formula : str
        Formula string, very simply formats only.
    check : bool
        If `check` is True, a simple check will be performed to determine if
        a formula is not a formula and an exception will be raised if it is
        not, [-]

    Returns
    -------
    atoms : dict
        dictionary of counts of individual atoms, indexed by symbol with
        proper capitalization, [-]

    Notes
    -----
    Inspired by the approach taken by CrazyMerlyn on a reddit DailyProgrammer
    challenge, at https://www.reddit.com/r/dailyprogrammer/comments/6eerfk/20170531_challenge_317_intermediate_counting/

    Examples
    --------
    >>> pprint(nested_formula_parser('Pd(NH3)4.0001+2'))
    {'H': 12.0003, 'N': 4.0001, 'Pd': 1}
    '''
    formula = formula.replace('[', '').replace(']', '')
    charge_splits = bracketed_charge_re.split(formula)
    if len(charge_splits) > 1:
        formula = charge_splits[0]
    else:
        formula = formula.split('+')[0].split('-')[0]

    stack = [[]]
    last = stack[0]
    tokens = formula_token_matcher_rational.findall(formula)
    # The set of letters in the tokens should match the set of letters
    if check:
        token_letters = set([j for i in tokens for j in i if j in letter_set])
        formula_letters = set(i for i in formula if i in letter_set)
        if formula_letters != token_letters:
            raise Exception('Input may not be a formula; extra letters were detected')

    for token in tokens:
        if token == "(":
            stack.append([])
            last = stack[-1]
        elif token == ")":
            temp_dict = {}
            for d in last:
                for ele, count in d.items():
                    if ele in temp_dict:
                        temp_dict[ele] = temp_dict[ele] + count
                    else:
                        temp_dict[ele] = count
            stack.pop()
            last = stack[-1]
            last.append(temp_dict)
        elif token.isalpha():
            last.append({token: 1})
        else:
            v = float(token)
            v_int = int(v)
            if v_int == v:
                v = v_int
            last[-1] = {ele: count*v for ele, count in last[-1].items()}
    ans = {}
    for d in last:
        for ele, count in d.items():
            if ele in ans:
                ans[ele] = ans[ele] + count
            else:
                ans[ele] = count
    return ans

Response: Improved formula parser which handles braces and multipliers and rational element counts.


Instruction:
Can you implement a function in Python 3 that
establishes a connection to the chat server. Returns when an error has occurred or a disconnect has been called.

Response:
async def connect(self):
        """Establish a connection to the chat server.

        Returns when an error has occurred, or :func:`disconnect` has been
        called.
        """
        proxy = os.environ.get('HTTP_PROXY')
        self._session = http_utils.Session(self._cookies, proxy=proxy)
        try:
            self._channel = channel.Channel(
                self._session, self._max_retries, self._retry_backoff_base
            )

            # Forward the Channel events to the Client events.
            self._channel.on_connect.add_observer(self.on_connect.fire)
            self._channel.on_reconnect.add_observer(self.on_reconnect.fire)
            self._channel.on_disconnect.add_observer(self.on_disconnect.fire)
            self._channel.on_receive_array.add_observer(self._on_receive_array)

            # Wrap the coroutine in a Future so it can be cancelled.
            self._listen_future = asyncio.ensure_future(self._channel.listen())
            # Listen for StateUpdate messages from the Channel until it
            # disconnects.
            try:
                await self._listen_future
            except asyncio.CancelledError:
                # If this task is cancelled, we need to cancel our child task
                # as well. We don't need an additional yield because listen
                # cancels immediately.
                self._listen_future.cancel()
            logger.info(
                'Client.connect returning because Channel.listen returned'
            )
        finally:
            await self._session.close()


Instruction:
Implement a function in Python 3 to
return the request header for use when constructing requests.

Response:
def get_request_header(self):
        """Return ``request_header`` for use when constructing requests.

        Returns:
            Populated request header.
        """
        # resource is allowed to be null if it's not available yet (the Chrome
        # client does this for the first getentitybyid call)
        if self._client_id is not None:
            self._request_header.client_identifier.resource = self._client_id
        return self._request_header


Instruction:
How would you implement a function in Python 3 that
sets this client as active.

Response:
async def set_active(self):
        """Set this client as active.

        While a client is active, no other clients will raise notifications.
        Call this method whenever there is an indication the user is
        interacting with this client. This method may be called very
        frequently, and it will only make a request when necessary.
        """
        is_active = (self._active_client_state ==
                     hangouts_pb2.ACTIVE_CLIENT_STATE_IS_ACTIVE)
        timed_out = (time.time() - self._last_active_secs >
                     SETACTIVECLIENT_LIMIT_SECS)
        if not is_active or timed_out:
            # Update these immediately so if the function is called again
            # before the API request finishes, we don't start extra requests.
            self._active_client_state = (
                hangouts_pb2.ACTIVE_CLIENT_STATE_IS_ACTIVE
            )
            self._last_active_secs = time.time()

            # The first time this is called, we need to retrieve the user's
            # email address.
            if self._email is None:
                try:
                    get_self_info_request = hangouts_pb2.GetSelfInfoRequest(
                        request_header=self.get_request_header(),
                    )
                    get_self_info_response = await self.get_self_info(
                        get_self_info_request
                    )
                except exceptions.NetworkError as e:
                    logger.warning('Failed to find email address: {}'
                                   .format(e))
                    return
                self._email = (
                    get_self_info_response.self_entity.properties.email[0]
                )

            # If the client_id hasn't been received yet, we can't set the
            # active client.
            if self._client_id is None:
                logger.info(
                    'Cannot set active client until client_id is received'
                )
                return

            try:
                set_active_request = hangouts_pb2.SetActiveClientRequest(
                    request_header=self.get_request_header(),
                    is_active=True,
                    full_jid="{}/{}".format(self._email, self._client_id),
                    timeout_secs=ACTIVE_TIMEOUT_SECS,
                )
                await self.set_active_client(set_active_request)
            except exceptions.NetworkError as e:
                logger.warning('Failed to set active client: {}'.format(e))
            else:
                logger.info('Set active client for {} seconds'
                            .format(ACTIVE_TIMEOUT_SECS))


Instruction:
Create a Python 3 function to
upload an image to the chat message.

Response:
async def upload_image(self, image_file, filename=None, *,
                           return_uploaded_image=False):
        """Upload an image that can be later attached to a chat message.

        Args:
            image_file: A file-like object containing an image.
            filename (str): (optional) Custom name for the uploaded file.
            return_uploaded_image (bool): (optional) If True, return
                :class:`.UploadedImage` instead of image ID. Defaults to False.

        Raises:
            hangups.NetworkError: If the upload request failed.

        Returns:
            :class:`.UploadedImage` instance, or ID of the uploaded image.
        """
        image_filename = filename or os.path.basename(image_file.name)
        image_data = image_file.read()

        # request an upload URL
        res = await self._base_request(
            IMAGE_UPLOAD_URL,
            'application/x-www-form-urlencoded;charset=UTF-8', 'json',
            json.dumps({
                "protocolVersion": "0.8",
                "createSessionRequest": {
                    "fields": [{
                        "external": {
                            "name": "file",
                            "filename": image_filename,
                            "put": {},
                            "size": len(image_data)
                        }
                    }]
                }
            })
        )

        try:
            upload_url = self._get_upload_session_status(res)[
                'externalFieldTransfers'
            ][0]['putInfo']['url']
        except KeyError:
            raise exceptions.NetworkError(
                'image upload failed: can not acquire an upload url'
            )

        # upload the image data using the upload_url to get the upload info
        res = await self._base_request(
            upload_url, 'application/octet-stream', 'json', image_data
        )

        try:
            raw_info = (
                self._get_upload_session_status(res)['additionalInfo']
                ['uploader_service.GoogleRupioAdditionalInfo']
                ['completionInfo']['customerSpecificInfo']
            )
            image_id = raw_info['photoid']
            url = raw_info['url']
        except KeyError:
            raise exceptions.NetworkError(
                'image upload failed: can not fetch upload info'
            )

        result = UploadedImage(image_id=image_id, url=url)
        return result if return_uploaded_image else result.image_id


Instruction:
Explain what the following Python 3 code does
def _get_upload_session_status(res):
        response = json.loads(res.body.decode())
        if 'sessionStatus' not in response:
            try:
                info = (
                    response['errorMessage']['additionalInfo']
                    ['uploader_service.GoogleRupioAdditionalInfo']
                    ['completionInfo']['customerSpecificInfo']
                )
                reason = '{} : {}'.format(info['status'], info['message'])
            except KeyError:
                reason = 'unknown reason'
            raise exceptions.NetworkError('image upload failed: {}'.format(
                reason
            ))
        return response['sessionStatus']

Response: Parse the response to obtain status.


Instruction:
Given the following Python 3 function, write the documentation
async def _on_receive_array(self, array):
        if array[0] == 'noop':
            pass  # This is just a keep-alive, ignore it.
        else:
            wrapper = json.loads(array[0]['p'])
            # Wrapper appears to be a Protocol Buffer message, but encoded via
            # field numbers as dictionary keys. Since we don't have a parser
            # for that, parse it ad-hoc here.
            if '3' in wrapper:
                # This is a new client_id.
                self._client_id = wrapper['3']['2']
                logger.info('Received new client_id: %r', self._client_id)
                # Once client_id is received, the channel is ready to have
                # services added.
                await self._add_channel_services()
            if '2' in wrapper:
                pblite_message = json.loads(wrapper['2']['2'])
                if pblite_message[0] == 'cbu':
                    # This is a (Client)BatchUpdate containing StateUpdate
                    # messages.
                    batch_update = hangouts_pb2.BatchUpdate()
                    pblite.decode(batch_update, pblite_message,
                                  ignore_first_item=True)
                    for state_update in batch_update.state_update:
                        logger.debug('Received StateUpdate:\n%s', state_update)
                        header = state_update.state_update_header
                        self._active_client_state = header.active_client_state
                        await self.on_state_update.fire(state_update)
                else:
                    logger.info('Ignoring message: %r', pblite_message[0])

Response: Parse the channel array and call the appropriate events.


Instruction:
Can you generate the documentation for the following Python 3 function
async def _add_channel_services(self):
        logger.info('Adding channel services...')
        # Based on what Hangouts for Chrome does over 2 requests, this is
        # trimmed down to 1 request that includes the bare minimum to make
        # things work.
        services = ["babel", "babel_presence_last_seen"]
        map_list = [
            dict(p=json.dumps({"3": {"1": {"1": service}}}))
            for service in services
        ]
        await self._channel.send_maps(map_list)
        logger.info('Channel services added')

Response: Add services to the channel.


Instruction:
Can you generate a brief explanation for the following Python 3 code
async def _pb_request(self, endpoint, request_pb, response_pb):
        logger.debug('Sending Protocol Buffer request %s:\n%s', endpoint,
                     request_pb)
        res = await self._base_request(
            'https://clients6.google.com/chat/v1/{}'.format(endpoint),
            'application/x-protobuf',  # Request body is Protocol Buffer.
            'proto',  # Response body is Protocol Buffer.
            request_pb.SerializeToString()
        )
        try:
            response_pb.ParseFromString(base64.b64decode(res.body))
        except binascii.Error as e:
            raise exceptions.NetworkError(
                'Failed to decode base64 response: {}'.format(e)
            )
        except google.protobuf.message.DecodeError as e:
            raise exceptions.NetworkError(
                'Failed to decode Protocol Buffer response: {}'.format(e)
            )
        logger.debug('Received Protocol Buffer response:\n%s', response_pb)
        status = response_pb.response_header.status
        if status != hangouts_pb2.RESPONSE_STATUS_OK:
            description = response_pb.response_header.error_description
            raise exceptions.NetworkError(
                'Request failed with status {}: \'{}\''
                .format(status, description)
            )

Response: Send a Protocol Buffer formatted chat API request.


Instruction:
Can you generate a brief explanation for the following Python 3 code
async def _base_request(self, url, content_type, response_type, data):
        headers = {
            'content-type': content_type,
            # This header is required for Protocol Buffer responses. It causes
            # them to be base64 encoded:
            'X-Goog-Encode-Response-If-Executable': 'base64',
        }
        params = {
            # "alternative representation type" (desired response format).
            'alt': response_type,
            # API key (required to avoid 403 Forbidden "Daily Limit for
            # Unauthenticated Use Exceeded. Continued use requires signup").
            'key': API_KEY,
        }
        res = await self._session.fetch(
            'post', url, headers=headers, params=params, data=data,
        )
        return res

Response: Send a generic authenticated POST request.


Instruction:
Make a summary of the following Python 3 code
async def add_user(self, add_user_request):
        response = hangouts_pb2.AddUserResponse()
        await self._pb_request('conversations/adduser',
                               add_user_request, response)
        return response

Response: Invite users to join an existing group conversation.


Instruction:
Can you implement a function in Python 3 that
creates a new conversation.

Response:
async def create_conversation(self, create_conversation_request):
        """Create a new conversation."""
        response = hangouts_pb2.CreateConversationResponse()
        await self._pb_request('conversations/createconversation',
                               create_conversation_request, response)
        return response


Instruction:
Write a Python 3 script to
leave a one - to - one conversation.

Response:
async def delete_conversation(self, delete_conversation_request):
        """Leave a one-to-one conversation.

        One-to-one conversations are "sticky"; they can't actually be deleted.
        This API clears the event history of the specified conversation up to
        ``delete_upper_bound_timestamp``, hiding it if no events remain.
        """
        response = hangouts_pb2.DeleteConversationResponse()
        await self._pb_request('conversations/deleteconversation',
                               delete_conversation_request, response)
        return response


Instruction:
Given the following Python 3 function, write the documentation
async def easter_egg(self, easter_egg_request):
        response = hangouts_pb2.EasterEggResponse()
        await self._pb_request('conversations/easteregg',
                               easter_egg_request, response)
        return response

Response: Send an easter egg event to a conversation.


Instruction:
Here you have a function in Python 3, explain what it does
async def get_conversation(self, get_conversation_request):
        response = hangouts_pb2.GetConversationResponse()
        await self._pb_request('conversations/getconversation',
                               get_conversation_request, response)
        return response

Response: Get conversation info and recent events.


Instruction:
Write a Python 3 function that can
return one or more user entities.

Response:
async def get_entity_by_id(self, get_entity_by_id_request):
        """Return one or more user entities.

        Searching by phone number only finds entities when their phone number
        is in your contacts (and not always even then), and can't be used to
        find Google Voice contacts.
        """
        response = hangouts_pb2.GetEntityByIdResponse()
        await self._pb_request('contacts/getentitybyid',
                               get_entity_by_id_request, response)
        return response


Instruction:
Write a Python 3 function for
getting URL to allow others to join a group conversation.

Response:
async def get_group_conversation_url(self,
                                         get_group_conversation_url_request):
        """Get URL to allow others to join a group conversation."""
        response = hangouts_pb2.GetGroupConversationUrlResponse()
        await self._pb_request('conversations/getgroupconversationurl',
                               get_group_conversation_url_request,
                               response)
        return response


Instruction:
Here you have a function in Python 3, explain what it does
async def get_self_info(self, get_self_info_request):
        response = hangouts_pb2.GetSelfInfoResponse()
        await self._pb_request('contacts/getselfinfo',
                               get_self_info_request, response)
        return response

Response: Returns info about the current user.


Instruction:
Implement a Python 3 function for
returning presence status for a list of users.

Response:
async def query_presence(self, query_presence_request):
        """Return presence status for a list of users."""
        response = hangouts_pb2.QueryPresenceResponse()
        await self._pb_request('presence/querypresence',
                               query_presence_request, response)
        return response


Instruction:
Create a Python 3 function for
removing a participant from a group conversation.

Response:
async def remove_user(self, remove_user_request):
        """Remove a participant from a group conversation."""
        response = hangouts_pb2.RemoveUserResponse()
        await self._pb_request('conversations/removeuser',
                               remove_user_request, response)
        return response


Instruction:
Can you tell what is the following Python 3 function doing
async def rename_conversation(self, rename_conversation_request):
        response = hangouts_pb2.RenameConversationResponse()
        await self._pb_request('conversations/renameconversation',
                               rename_conversation_request, response)
        return response

Response:
Rename a conversation.

        Both group and one-to-one conversations may be renamed, but the
        official Hangouts clients have mixed support for one-to-one
        conversations with custom names.


Instruction:
Create a Python 3 function for
returning user entities based on a query.

Response:
async def search_entities(self, search_entities_request):
        """Return user entities based on a query."""
        response = hangouts_pb2.SearchEntitiesResponse()
        await self._pb_request('contacts/searchentities',
                               search_entities_request, response)
        return response


Instruction:
Can you create a Python 3 function that
sends a chat message to a conversation.

Response:
async def send_chat_message(self, send_chat_message_request):
        """Send a chat message to a conversation."""
        response = hangouts_pb2.SendChatMessageResponse()
        await self._pb_request('conversations/sendchatmessage',
                               send_chat_message_request, response)
        return response


Instruction:
How would you code a function in Python 3 to
enable or disable message history in a conversation.

Response:
async def modify_otr_status(self, modify_otr_status_request):
        """Enable or disable message history in a conversation."""
        response = hangouts_pb2.ModifyOTRStatusResponse()
        await self._pb_request('conversations/modifyotrstatus',
                               modify_otr_status_request, response)
        return response


Instruction:
Can you generate the documentation for the following Python 3 function
async def send_offnetwork_invitation(
            self, send_offnetwork_invitation_request
    ):
        """Send an email to invite a non-Google contact to Hangouts."""
        response = hangouts_pb2.SendOffnetworkInvitationResponse()
        await self._pb_request('devices/sendoffnetworkinvitation',
                               send_offnetwork_invitation_request,
                               response)
        return response

Response: Send an email to invite a non - Google contact to Hangouts.


Instruction:
How would you code a function in Python 3 to
set the active client.

Response:
async def set_active_client(self, set_active_client_request):
        """Set the active client."""
        response = hangouts_pb2.SetActiveClientResponse()
        await self._pb_request('clients/setactiveclient',
                               set_active_client_request, response)
        return response


Instruction:
Given the following Python 3 function, write the documentation
async def set_conversation_notification_level(
            self, set_conversation_notification_level_request
    ):
        """Set the notification level of a conversation."""
        response = hangouts_pb2.SetConversationNotificationLevelResponse()
        await self._pb_request(
            'conversations/setconversationnotificationlevel',
            set_conversation_notification_level_request, response
        )
        return response

Response: Set the notification level of a conversation.


Instruction:
Create a Python 3 function for
setting focus to a conversation.

Response:
async def set_focus(self, set_focus_request):
        """Set focus to a conversation."""
        response = hangouts_pb2.SetFocusResponse()
        await self._pb_request('conversations/setfocus',
                               set_focus_request, response)
        return response


Instruction:
Can you generate a brief explanation for the following Python 3 code
async def set_group_link_sharing_enabled(
            self, set_group_link_sharing_enabled_request
    ):
        """Set whether group link sharing is enabled for a conversation."""
        response = hangouts_pb2.SetGroupLinkSharingEnabledResponse()
        await self._pb_request('conversations/setgrouplinksharingenabled',
                               set_group_link_sharing_enabled_request,
                               response)
        return response

Response: Sets whether group link sharing is enabled for a conversation.


Instruction:
Can you generate the documentation for the following Python 3 function
async def set_presence(self, set_presence_request):
        response = hangouts_pb2.SetPresenceResponse()
        await self._pb_request('presence/setpresence',
                               set_presence_request, response)
        return response

Response: Set the presence status.


Instruction:
Explain what the following Python 3 code does
async def set_typing(self, set_typing_request):
        response = hangouts_pb2.SetTypingResponse()
        await self._pb_request('conversations/settyping',
                               set_typing_request, response)
        return response

Response: Sets the typing status of a conversation.


Instruction:
Can you write a function in Python 3 where it
lists all events occurring at or after a timestamp.

Response:
async def sync_all_new_events(self, sync_all_new_events_request):
        """List all events occurring at or after a timestamp."""
        response = hangouts_pb2.SyncAllNewEventsResponse()
        await self._pb_request('conversations/syncallnewevents',
                               sync_all_new_events_request, response)
        return response


Instruction:
Explain what the following Python 3 code does
async def sync_recent_conversations(
            self, sync_recent_conversations_request
    ):
        """Return info on recent conversations and their events."""
        response = hangouts_pb2.SyncRecentConversationsResponse()
        await self._pb_request('conversations/syncrecentconversations',
                               sync_recent_conversations_request,
                               response)
        return response

Response: Return info on recent conversations and their events.


Instruction:
Here you have a function in Python 3, explain what it does
async def update_watermark(self, update_watermark_request):
        response = hangouts_pb2.UpdateWatermarkResponse()
        await self._pb_request('conversations/updatewatermark',
                               update_watermark_request, response)
        return response

Response: Update the watermark ( read timestamp of a conversation.


Instruction:
Can you tell what is the following Python 3 function doing
def from_timestamp(microsecond_timestamp):
    # Create datetime without losing precision from floating point (yes, this
    # is actually needed):
    return datetime.datetime.fromtimestamp(
        microsecond_timestamp // 1000000, datetime.timezone.utc
    ).replace(microsecond=(microsecond_timestamp % 1000000))

Response: Convert a microsecond timestamp to a UTC datetime instance.


Instruction:
Write a Python 3 function for
converting hangouts_pb2. ParticipantId to UserID.

Response:
def from_participantid(participant_id):
    """Convert hangouts_pb2.ParticipantId to UserID."""
    return user.UserID(
        chat_id=participant_id.chat_id,
        gaia_id=participant_id.gaia_id
    )


Instruction:
Given the following Python 3 function, write the documentation
def to_participantid(user_id):
    return hangouts_pb2.ParticipantId(
        chat_id=user_id.chat_id,
        gaia_id=user_id.gaia_id
    )

Response: Convert a userID to a ParticipantId.


Instruction:
How would you explain what the following Python 3 function does
def parse_typing_status_message(p):
    return TypingStatusMessage(
        conv_id=p.conversation_id.id,
        user_id=from_participantid(p.sender_id),
        timestamp=from_timestamp(p.timestamp),
        status=p.type,
    )

Response: Return TypingStatusMessage from hangouts_pb2. SetTypingNotification.


Instruction:
Make a summary of the following Python 3 code
def parse_watermark_notification(p):
    return WatermarkNotification(
        conv_id=p.conversation_id.id,
        user_id=from_participantid(p.sender_id),
        read_timestamp=from_timestamp(
            p.latest_read_timestamp
        ),
    )

Response: Return WatermarkNotification from hangouts_pb2. WatermarkNotification.


Instruction:
How would you implement a function in Python 3 that
returns the authorization headers for API request.

Response:
def _get_authorization_headers(sapisid_cookie):
    """Return authorization headers for API request."""
    # It doesn't seem to matter what the url and time are as long as they are
    # consistent.
    time_msec = int(time.time() * 1000)
    auth_string = '{} {} {}'.format(time_msec, sapisid_cookie, ORIGIN_URL)
    auth_hash = hashlib.sha1(auth_string.encode()).hexdigest()
    sapisidhash = 'SAPISIDHASH {}_{}'.format(time_msec, auth_hash)
    return {
        'authorization': sapisidhash,
        'x-origin': ORIGIN_URL,
        'x-goog-authuser': '0',
    }


Instruction:
Make a summary of the following Python 3 code
async def fetch(self, method, url, params=None, headers=None, data=None):
        logger.debug('Sending request %s %s:\n%r', method, url, data)
        for retry_num in range(MAX_RETRIES):
            try:
                async with self.fetch_raw(method, url, params=params,
                                          headers=headers, data=data) as res:
                    async with async_timeout.timeout(REQUEST_TIMEOUT):
                        body = await res.read()
                logger.debug('Received response %d %s:\n%r',
                             res.status, res.reason, body)
            except asyncio.TimeoutError:
                error_msg = 'Request timed out'
            except aiohttp.ServerDisconnectedError as err:
                error_msg = 'Server disconnected error: {}'.format(err)
            except (aiohttp.ClientError, ValueError) as err:
                error_msg = 'Request connection error: {}'.format(err)
            else:
                break
            logger.info('Request attempt %d failed: %s', retry_num, error_msg)
        else:
            logger.info('Request failed after %d attempts', MAX_RETRIES)
            raise exceptions.NetworkError(error_msg)

        if res.status != 200:
            logger.info('Request returned unexpected status: %d %s',
                        res.status, res.reason)
            raise exceptions.NetworkError(
                'Request return unexpected status: {}: {}'
                .format(res.status, res.reason)
            )

        return FetchResponse(res.status, body)

Response: Make an HTTP request to the specified URL and return the response.


Instruction:
How would you code a function in Python 3 to
make an HTTP request using aiohttp directly.

Response:
def fetch_raw(self, method, url, params=None, headers=None, data=None):
        """Make an HTTP request using aiohttp directly.

        Automatically uses configured HTTP proxy, and adds Google authorization
        header and cookies.

        Args:
            method (str): Request method.
            url (str): Request URL.
            params (dict): (optional) Request query string parameters.
            headers (dict): (optional) Request headers.
            data: (str): (optional) Request body data.

        Returns:
            aiohttp._RequestContextManager: ContextManager for a HTTP response.

        Raises:
            See ``aiohttp.ClientSession.request``.
        """
        # Ensure we don't accidentally send the authorization header to a
        # non-Google domain:
        if not urllib.parse.urlparse(url).hostname.endswith('.google.com'):
            raise Exception('expected google.com domain')

        headers = headers or {}
        headers.update(self._authorization_headers)
        return self._session.request(
            method, url, params=params, headers=headers, data=data,
            proxy=self._proxy
        )


Instruction:
Write a Python 3 script for
searching for entities by phone number email or gaia_id.

Response:
async def lookup_entities(client, args):
    """Search for entities by phone number, email, or gaia_id."""
    lookup_spec = _get_lookup_spec(args.entity_identifier)
    request = hangups.hangouts_pb2.GetEntityByIdRequest(
        request_header=client.get_request_header(),
        batch_lookup_spec=[lookup_spec],
    )
    res = await client.get_entity_by_id(request)

    # Print the list of entities in the response.
    for entity_result in res.entity_result:
        for entity in entity_result.entity:
            print(entity)


Instruction:
How would you explain what the following Python 3 function does
def _get_lookup_spec(identifier):
    if identifier.startswith('+'):
        return hangups.hangouts_pb2.EntityLookupSpec(
            phone=identifier, create_offnetwork_gaia=True
        )
    elif '@' in identifier:
        return hangups.hangouts_pb2.EntityLookupSpec(
            email=identifier, create_offnetwork_gaia=True
        )
    else:
        return hangups.hangouts_pb2.EntityLookupSpec(gaia_id=identifier)

Response: Return EntityLookupSpec from phone number email address or gaia ID.


Instruction:
How would you implement a function in Python 3 that
returns a readable name for a conversation.

Response:
def get_conv_name(conv, truncate=False, show_unread=False):
    """Return a readable name for a conversation.

    If the conversation has a custom name, use the custom name. Otherwise, for
    one-to-one conversations, the name is the full name of the other user. For
    group conversations, the name is a comma-separated list of first names. If
    the group conversation is empty, the name is "Empty Conversation".

    If truncate is true, only show up to two names in a group conversation.

    If show_unread is True, if there are unread chat messages, show the number
    of unread chat messages in parentheses after the conversation name.
    """
    num_unread = len([conv_event for conv_event in conv.unread_events if
                      isinstance(conv_event, hangups.ChatMessageEvent) and
                      not conv.get_user(conv_event.user_id).is_self])
    if show_unread and num_unread > 0:
        postfix = ' ({})'.format(num_unread)
    else:
        postfix = ''
    if conv.name is not None:
        return conv.name + postfix
    else:
        participants = sorted(
            (user for user in conv.users if not user.is_self),
            key=lambda user: user.id_
        )
        names = [user.first_name for user in participants]
        if not participants:
            return "Empty Conversation" + postfix
        if len(participants) == 1:
            return participants[0].full_name + postfix
        elif truncate and len(participants) > 2:
            return (', '.join(names[:2] + ['+{}'.format(len(names) - 2)]) +
                    postfix)
        else:
            return ', '.join(names) + postfix


Instruction:
How would you explain what the following Python 3 function does
def add_color_to_scheme(scheme, name, foreground, background, palette_colors):
    if foreground is None and background is None:
        return scheme

    new_scheme = []
    for item in scheme:
        if item[0] == name:
            if foreground is None:
                foreground = item[1]
            if background is None:
                background = item[2]
            if palette_colors > 16:
                new_scheme.append((name, '', '', '', foreground, background))
            else:
                new_scheme.append((name, foreground, background))
        else:
            new_scheme.append(item)
    return new_scheme

Response: Add foreground and background colours to a color scheme


Instruction:
Given the following Python 3 function, write the documentation
async def build_user_conversation_list(client):
    conv_states, sync_timestamp = await _sync_all_conversations(client)

    # Retrieve entities participating in all conversations.
    required_user_ids = set()
    for conv_state in conv_states:
        required_user_ids |= {
            user.UserID(chat_id=part.id.chat_id, gaia_id=part.id.gaia_id)
            for part in conv_state.conversation.participant_data
        }
    required_entities = []
    if required_user_ids:
        logger.debug('Need to request additional users: {}'
                     .format(required_user_ids))
        try:
            response = await client.get_entity_by_id(
                hangouts_pb2.GetEntityByIdRequest(
                    request_header=client.get_request_header(),
                    batch_lookup_spec=[
                        hangouts_pb2.EntityLookupSpec(
                            gaia_id=user_id.gaia_id,
                            create_offnetwork_gaia=True,
                        )
                        for user_id in required_user_ids
                    ],
                )
            )
            for entity_result in response.entity_result:
                required_entities.extend(entity_result.entity)
        except exceptions.NetworkError as e:
            logger.warning('Failed to request missing users: {}'.format(e))

    # Build list of conversation participants.
    conv_part_list = []
    for conv_state in conv_states:
        conv_part_list.extend(conv_state.conversation.participant_data)

    # Retrieve self entity.
    get_self_info_response = await client.get_self_info(
        hangouts_pb2.GetSelfInfoRequest(
            request_header=client.get_request_header(),
        )
    )
    self_entity = get_self_info_response.self_entity

    user_list = user.UserList(client, self_entity, required_entities,
                              conv_part_list)
    conversation_list = ConversationList(client, conv_states,
                                         user_list, sync_timestamp)
    return (user_list, conversation_list)

Response: Builds a list of conversations and participants for a user.


Instruction:
Can you create a Python 3 function that
lists of users in the conversation.

Response:
def users(self):
        """List of conversation participants (:class:`~hangups.user.User`)."""
        return [self._user_list.get_user(user.UserID(chat_id=part.id.chat_id,
                                                     gaia_id=part.id.gaia_id))
                for part in self._conversation.participant_data]


Instruction:
Given the following Python 3 function, write the documentation
def unread_events(self):
        return [conv_event for conv_event in self._events
                if conv_event.timestamp > self.latest_read_timestamp]

Response: Returns a list of all unread event items in the event cache sorted oldest to newest.


Instruction:
Implement a function in Python 3 to
true if the notification level for this conversation is quiet.

Response:
def is_quiet(self):
        """``True`` if notification level for this conversation is quiet."""
        level = self._conversation.self_conversation_state.notification_level
        return level == hangouts_pb2.NOTIFICATION_LEVEL_QUIET


Instruction:
Can you write a function in Python 3 where it
handles a watermark notification.

Response:
def _on_watermark_notification(self, notif):
        """Handle a watermark notification."""
        # Update the conversation:
        if self.get_user(notif.user_id).is_self:
            logger.info('latest_read_timestamp for {} updated to {}'
                        .format(self.id_, notif.read_timestamp))
            self_conversation_state = (
                self._conversation.self_conversation_state
            )
            self_conversation_state.self_read_state.latest_read_timestamp = (
                parsers.to_timestamp(notif.read_timestamp)
            )
        # Update the participants' watermarks:
        previous_timestamp = self._watermarks.get(
            notif.user_id,
            datetime.datetime.min.replace(tzinfo=datetime.timezone.utc)
        )
        if notif.read_timestamp > previous_timestamp:
            logger.info(('latest_read_timestamp for conv {} participant {}' +
                         ' updated to {}').format(self.id_,
                                                  notif.user_id.chat_id,
                                                  notif.read_timestamp))
            self._watermarks[notif.user_id] = notif.read_timestamp


Instruction:
Given the following Python 3 function, write the documentation
def update_conversation(self, conversation):
        # StateUpdate.conversation is actually a delta; fields that aren't
        # specified are assumed to be unchanged. Until this class is
        # refactored, hide this by saving and restoring previous values where
        # necessary.

        new_state = conversation.self_conversation_state
        old_state = self._conversation.self_conversation_state
        self._conversation = conversation

        # delivery_medium_option
        if not new_state.delivery_medium_option:
            new_state.delivery_medium_option.extend(
                old_state.delivery_medium_option
            )

        # latest_read_timestamp
        old_timestamp = old_state.self_read_state.latest_read_timestamp
        new_timestamp = new_state.self_read_state.latest_read_timestamp
        if new_timestamp == 0:
            new_state.self_read_state.latest_read_timestamp = old_timestamp

        # user_read_state(s)
        for new_entry in conversation.read_state:
            tstamp = parsers.from_timestamp(new_entry.latest_read_timestamp)
            if tstamp == 0:
                continue
            uid = parsers.from_participantid(new_entry.participant_id)
            if uid not in self._watermarks or self._watermarks[uid] < tstamp:
                self._watermarks[uid] = tstamp

Response: Updates the internal state of the conversation.


Instruction:
How would you explain what the following Python 3 function does
def _wrap_event(event_):
        cls = conversation_event.ConversationEvent
        if event_.HasField('chat_message'):
            cls = conversation_event.ChatMessageEvent
        elif event_.HasField('otr_modification'):
            cls = conversation_event.OTREvent
        elif event_.HasField('conversation_rename'):
            cls = conversation_event.RenameEvent
        elif event_.HasField('membership_change'):
            cls = conversation_event.MembershipChangeEvent
        elif event_.HasField('hangout_event'):
            cls = conversation_event.HangoutEvent
        elif event_.HasField('group_link_sharing_modification'):
            cls = conversation_event.GroupLinkSharingModificationEvent
        return cls(event_)

Response: Wrap hangouts_pb2. Event in ConversationEvent subclass.


Instruction:
Write a Python 3 function that can
add an event to the conversation.

Response:
def add_event(self, event_):
        """Add an event to the conversation.

        This method is used by :class:`.ConversationList` to maintain this
        instance.

        Args:
            event_: ``Event`` message.

        Returns:
            :class:`.ConversationEvent` representing the event.
        """
        conv_event = self._wrap_event(event_)
        if conv_event.id_ not in self._events_dict:
            self._events.append(conv_event)
            self._events_dict[conv_event.id_] = conv_event
        else:
            # If this happens, there's probably a bug.
            logger.info('Conversation %s ignoring duplicate event %s',
                        self.id_, conv_event.id_)
            return None
        return conv_event


Instruction:
How would you implement a function in Python 3 that
returns default delivery medium to use for sending messages.

Response:
def _get_default_delivery_medium(self):
        """Return default DeliveryMedium to use for sending messages.

        Use the first option, or an option that's marked as the current
        default.
        """
        medium_options = (
            self._conversation.self_conversation_state.delivery_medium_option
        )
        try:
            default_medium = medium_options[0].delivery_medium
        except IndexError:
            logger.warning('Conversation %r has no delivery medium', self.id_)
            default_medium = hangouts_pb2.DeliveryMedium(
                medium_type=hangouts_pb2.DELIVERY_MEDIUM_BABEL
            )
        for medium_option in medium_options:
            if medium_option.current_default:
                default_medium = medium_option.delivery_medium
        return default_medium


Instruction:
How would you code a function in Python 3 to
return EventRequestHeader for conversation.

Response:
def _get_event_request_header(self):
        """Return EventRequestHeader for conversation."""
        otr_status = (hangouts_pb2.OFF_THE_RECORD_STATUS_OFF_THE_RECORD
                      if self.is_off_the_record else
                      hangouts_pb2.OFF_THE_RECORD_STATUS_ON_THE_RECORD)
        return hangouts_pb2.EventRequestHeader(
            conversation_id=hangouts_pb2.ConversationId(id=self.id_),
            client_generated_id=self._client.get_client_generated_id(),
            expected_otr=otr_status,
            delivery_medium=self._get_default_delivery_medium(),
        )


Instruction:
Given the following Python 3 function, write the documentation
async def send_message(self, segments, image_file=None, image_id=None,
                           image_user_id=None):
        """Send a message to this conversation.

        A per-conversation lock is acquired to ensure that messages are sent in
        the correct order when this method is called multiple times
        asynchronously.

        Args:
            segments: List of :class:`.ChatMessageSegment` objects to include
                in the message.
            image_file: (optional) File-like object containing an image to be
                attached to the message.
            image_id: (optional) ID of an Picasa photo to be attached to the
                message. If you specify both ``image_file`` and ``image_id``
                together, ``image_file`` takes precedence and ``image_id`` will
                be ignored.
            image_user_id: (optional) Picasa user ID, required only if
                ``image_id`` refers to an image from a different Picasa user,
                such as Google's sticker user.

        Raises:
            .NetworkError: If the message cannot be sent.
        """
        async with self._send_message_lock:
            if image_file:
                try:
                    uploaded_image = await self._client.upload_image(
                        image_file, return_uploaded_image=True
                    )
                except exceptions.NetworkError as e:
                    logger.warning('Failed to upload image: {}'.format(e))
                    raise
                image_id = uploaded_image.image_id
            try:
                request = hangouts_pb2.SendChatMessageRequest(
                    request_header=self._client.get_request_header(),
                    event_request_header=self._get_event_request_header(),
                    message_content=hangouts_pb2.MessageContent(
                        segment=[seg.serialize() for seg in segments],
                    ),
                )
                if image_id is not None:
                    request.existing_media.photo.photo_id = image_id
                if image_user_id is not None:
                    request.existing_media.photo.user_id = image_user_id
                    request.existing_media.photo.is_custom_user_id = True
                await self._client.send_chat_message(request)
            except exceptions.NetworkError as e:
                logger.warning('Failed to send message: {}'.format(e))
                raise

Response: Sends a message to the current conversation.


Instruction:
Make a summary of the following Python 3 code
async def leave(self):
        is_group_conversation = (self._conversation.type ==
                                 hangouts_pb2.CONVERSATION_TYPE_GROUP)
        try:
            if is_group_conversation:
                await self._client.remove_user(
                    hangouts_pb2.RemoveUserRequest(
                        request_header=self._client.get_request_header(),
                        event_request_header=self._get_event_request_header(),
                    )
                )
            else:
                await self._client.delete_conversation(
                    hangouts_pb2.DeleteConversationRequest(
                        request_header=self._client.get_request_header(),
                        conversation_id=hangouts_pb2.ConversationId(
                            id=self.id_
                        ),
                        delete_upper_bound_timestamp=parsers.to_timestamp(
                            datetime.datetime.now(tz=datetime.timezone.utc)
                        )
                    )
                )
        except exceptions.NetworkError as e:
            logger.warning('Failed to leave conversation: {}'.format(e))
            raise

Response: Leaves the current conversation.


Instruction:
Write a Python 3 script to
rename this conversation. Hangouts only officially supports renaming group conversations, so custom names for one-to-one conversations may or may not appear in all first party clients. Args: name (str): New name. Raises: .NetworkError: If conversation cannot be renamed.

Response:
async def rename(self, name):
        """Rename this conversation.

        Hangouts only officially supports renaming group conversations, so
        custom names for one-to-one conversations may or may not appear in all
        first party clients.

        Args:
            name (str): New name.

        Raises:
            .NetworkError: If conversation cannot be renamed.
        """
        await self._client.rename_conversation(
            hangouts_pb2.RenameConversationRequest(
                request_header=self._client.get_request_header(),
                new_name=name,
                event_request_header=self._get_event_request_header(),
            )
        )


Instruction:
Implement a function in Python 3 to
set the notification level of this conversation.

Response:
async def set_notification_level(self, level):
        """Set the notification level of this conversation.

        Args:
            level: ``NOTIFICATION_LEVEL_QUIET`` to disable notifications, or
                ``NOTIFICATION_LEVEL_RING`` to enable them.

        Raises:
            .NetworkError: If the request fails.
        """
        await self._client.set_conversation_notification_level(
            hangouts_pb2.SetConversationNotificationLevelRequest(
                request_header=self._client.get_request_header(),
                conversation_id=hangouts_pb2.ConversationId(id=self.id_),
                level=level,
            )
        )


Instruction:
Explain what the following Python 3 code does
async def set_typing(self, typing=hangouts_pb2.TYPING_TYPE_STARTED):
        # TODO: Add rate-limiting to avoid unnecessary requests.
        try:
            await self._client.set_typing(
                hangouts_pb2.SetTypingRequest(
                    request_header=self._client.get_request_header(),
                    conversation_id=hangouts_pb2.ConversationId(id=self.id_),
                    type=typing,
                )
            )
        except exceptions.NetworkError as e:
            logger.warning('Failed to set typing status: {}'.format(e))
            raise

Response: Sets the typing status in this conversation.