File size: 3,279 Bytes
c12ef43 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 | # AI-generated module (ChatGPT)
import re
# Escape sequences expanded inside quoted values. Double-quoted values additionally
# expand "\$" to "$"; single-quoted values keep it verbatim.
_ESCAPES = {"n": "\n", "t": "\t", '"': '"', "\\": "\\"}
_DOUBLE_QUOTE_ESCAPES = {**_ESCAPES, "$": "$"}
def _unescape(value: str, escapes: dict[str, str]) -> str:
r"""Expand backslash escapes in a single left-to-right pass.
Processing in one pass (rather than chained `str.replace` calls) ensures an escaped
backslash (`\\`) is consumed as a unit and cannot merge with the following character,
e.g. `\\n` is a backslash followed by `n`, not a newline. Unknown escapes are kept as-is.
"""
return re.sub(r"\\(.)", lambda match: escapes.get(match.group(1), match.group(0)), value)
def load_dotenv(dotenv_str: str, environ: dict[str, str] | None = None) -> dict[str, str]:
"""
Parse a DOTENV-format string and return a dictionary of key-value pairs.
Handles quoted values, comments, export keyword, and blank lines.
"""
env: dict[str, str] = {}
line_pattern = re.compile(
r"""
\s*
(?:export[^\S\n]+)? # optional export
([A-Za-z_][A-Za-z0-9_]*) # key
(?:
[^\S\n]*
(=) # equal sign
(?:
[^\S\n]*
( # quoted value
'(?:\\'|[^'])*' # single-quoted
| \"(?:\\\"|[^\"])*\" # double-quoted
)
[^\S\n]*(?:\#[^\n\r]*)? # inline comment (needs no preceding whitespace after a quote)
|
(?:[^\S\n]+(?!\#))? # whitespace after '=' also separates an inline comment
( # unquoted value (may contain '#')
[^\n\r]*?
)
(?:[^\S\n]+\#[^\n\r]*)? # inline comment (must be preceded by whitespace)
)
|
[^\S\n]*(?:\#[^\n\r]*)? # bare key (no '='), with an optional inline comment
)
""",
re.VERBOSE,
)
for line in dotenv_str.splitlines():
line = line.strip()
if not line or line.startswith("#"):
continue # Skip comments and empty lines
match = line_pattern.fullmatch(line)
if match:
key = match.group(1)
val = None
if match.group(2): # if there is '='
raw_val = match.group(3) or match.group(4) or ""
val = raw_val.strip()
# Remove surrounding quotes if quoted
if val.startswith('"') and val.endswith('"'):
# Double-quoted values expand escape sequences (\n, \t, \", \\, \$).
val = _unescape(val[1:-1], _DOUBLE_QUOTE_ESCAPES)
elif val.startswith("'") and val.endswith("'"):
# Single-quoted values are kept verbatim: no escape expansion.
val = val[1:-1]
elif environ is not None:
# Get it from the current environment
val = environ.get(key)
if val is not None:
env[key] = val
return env
|