Python (re)

.env File Key-Value Line in PY

Parse KEY=value lines from .env config files, handling quoted values and trailing comments.

Try it in the PY tester →

Pattern

regexPY
^([A-Z_][A-Z0-9_]*)\s*=\s*(?:"([^"]*)"|'([^']*)'|([^#\s]*))(?:\s*#.*)?$   (flags: m)

Python (re) code

pyPython
import re

pattern = re.compile(r"^([A-Z_][A-Z0-9_]*)\\s*=\\s*(?:\"([^\"]*)\"|'([^']*)'|([^#\\s]*))(?:\\s*#.*)?$", re.MULTILINE)
input_text = "DATABASE_URL=postgres://localhost/db"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

How the pattern works

([A-Z_][A-Z0-9_]*) captures the variable name (uppercase + underscores by convention). The value alternation supports double-quoted, single-quoted, and unquoted values. (?:\s*#.*)? allows an optional inline comment. The m flag lets ^ and $ match individual lines in a multi-line file.

Examples

Input

DATABASE_URL=postgres://localhost/db

Matches

  • DATABASE_URL=postgres://localhost/db

Input

API_KEY="sk_live_abc123" # production

Matches

  • API_KEY="sk_live_abc123" # production

Input

lowercase=bad

No match

—

Same pattern, other engines

JavaScript / ECMAScript

Supported

See how this pattern looks (and behaves) in JavaScript's built-in RegExp.

Go (RE2)

Supported

See how this pattern looks (and behaves) in Go's `regexp` package (RE2 engine).

← Back to .env File Key-Value Line overview (all engines)