Secure Password Generator
This utility generates cryptographically strong passwords using the secrets module. It allows customization of password length and character sets (symbols, numbers).
Modules Used:
- secrets: For generating cryptographically strong random numbers.
string: For accessing pre-defined character sets (letters, digits, punctuation).- argparse: To handle command-line arguments.
Quick Start (Tokens)
If you just need a secure random string (e.g., for an API key or a password where specific character classes aren't required), the simplest method is secrets.token_urlsafe().
import secrets
# Generates a random URL-safe text string, containing nbytes random bytes.
print(secrets.token_urlsafe(16)) The Code
Save this as passgen.py.
import secrets
import string
import argparse
def generate_password(length, use_symbols, use_numbers):
# 1. Define Character Sets
letters = string.ascii_letters # a-z, A-Z
digits = string.digits # 0-9
symbols = string.punctuation # ! " # $ % ...
# 2. Build the Pool
pool = letters
if use_numbers:
pool += digits
if use_symbols:
pool += symbols
# 3. Generate until constraints are met
# We use a loop to ensure the password contains at least one of each selected type
while True:
password = ''.join(secrets.choice(pool) for _ in range(length))
# Check constraints
has_letter = any(c in letters for c in password)
has_digit = any(c in digits for c in password) if use_numbers else True
has_symbol = any(c in symbols for c in password) if use_symbols else True
if has_letter and has_digit and has_symbol:
return password
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Secure Password Generator")
parser.add_argument("-l", "--length", type=int, default=16, help="Length of the password (default: 16)")
parser.add_argument("--no-symbols", action="store_true", help="Exclude symbols")
parser.add_argument("--no-numbers", action="store_true", help="Exclude numbers")
args = parser.parse_args()
# Note: Arguments are negative flags (--no-X), so we invert them for the function
pwd = generate_password(args.length, not args.no_symbols, not args.no_numbers)
print(f"Generated Password: {pwd}")Usage
# Default (16 chars, symbols and numbers included)
python passgen.py
# 20 characters, no symbols
python passgen.py --length 20 --no-symbols