dotenv-mini

A strict, predictable .env reader/writer for Python 3.10+. Zero dependencies.

• Round-trip safe: loads(dumps(d)) == d for every dict of strings.
• No $VAR / ${VAR} interpolation — values are always literal.
• Strict grammar — malformed lines raise DotenvError, never silently swallowed.
• Single-quoted values are verbatim. Double-quoted values support \n, \r, \t, \", \\.

Install

pip install dotenv-mini

Or from a clone:

pip install -e .

Quick start

from dotenv_mini import loads, dumps, load, dump

d = loads("""
# Database
DB_HOST=localhost
DB_PORT=5432
DB_PASS="se cr et"
""")
# {'DB_HOST': 'localhost', 'DB_PORT': '5432', 'DB_PASS': 'se cr et'}

print(dumps({"NAME": "alice", "GREETING": "hello\nworld"}))
# NAME=alice
# GREETING="hello\nworld"

API reference

Symbol	Purpose
loads(text)	Parse .env text → dict.
dumps(d)	Serialize dict → .env text.
load(path)	Read file at path, return dict.
dump(d, path)	Write dict to file at path.
parse(text)	Yield (key, value, raw_line) tuples.
DotenvError	ValueError subclass for any malformed input.

Grammar

line       := blank | comment | assignment
comment    := whitespace* '#' anything
assignment := whitespace* ['export' whitespace+] KEY whitespace* '=' value
KEY        := [A-Za-z_][A-Za-z0-9_]*
value      := '' | bare | single-quoted | double-quoted

A trailing inline comment after a bare value requires at least one space before the #.

Running tests

pip install -e ".[dev]"
pytest -q

License

MIT.