How to Audit Environment Variable Files for Missing Values in Python

import os
import re
from pathlib import Path

def audit_env_file(filepath: str) -> None:
    """
    Audit an environment variable file for missing values.
    Prints file status and lists variables that have empty values.
    """
    path = Path(filepath)
    if not path.exists():
        print(f"Error: File '{filepath}' not found.")
        return

    missing = []
    with open(path, 'r') as f:
        for i, line in enumerate(f, 1):
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            match = re.match(r'^([A-Za-z_]\w*)=(.*)$', line)
            if match:
                var_name = match.group(1)
                var_value = match.group(2).strip()
                if not var_value or var_value in ('""', "''"):
                    missing.append((i, var_name))
            else:
                print(f"Warning: malformed line {i}: '{line}'")

    print(f"Audit of '{filepath}' ({len(missing)} missing value(s)):")
    if missing:
        for line_num, var in missing:
            print(f"  Line {line_num}: '{var}' is empty")
    else:
        print("  All variables have assigned values.")

if __name__ == "__main__":
    audit_env_file(".env.example")