Strings &amp; text

import re

COMMON_PASSWORDS_FILE = "common_passwords.txt"

def is_weak(password):
    # Check length
    if len(password) < 8:
        return True
    # Check for common patterns
    if password.lower() in {"password", "123456", "qwerty", "letmein", "admin", "welcome"}:
        return True
    # Check for sequential c…

54 0 Open

Build a Secure Password Strength Checker in Python

A Python function that evaluates password strength based on length and character diversity, returning Weak, Moderate, or Strong.

password security regex

import re

def password_strength(password: str) -> str:
    score = 0
    if len(password) >= 8:
        score += 1
    if re.search(r'[a-z]', password):
        score += 1
    if re.search(r'[A-Z]', password):
        score += 1
    if re.search(r'\d', password):
        score += 1
    if re.search(r'[!@#$%^&*(),.?":…

55 0 Open

string alphanumeric validation

How to Check if a String is Alphanumeric in Python

Uses the built-in str.isalnum() method to test whether a string contains only letters and numbers.

def is_alphanumeric(s: str) -> bool:
    return s.isalnum()

if __name__ == "__main__":
    test_cases = ["Hello123", "Hello World", "12345", "", "Hello@World", "Python3"]
    for case in test_cases:
        result = is_alphanumeric(case)
        print(f"{case!r:15} -> {result}")

numeric validation strings

How to Check if a String is Numeric in Python

This code provides a function to determine if a string represents a valid numeric value using Python's built-in float() conversion.

def is_numeric(s):
    """Check if a string represents a valid numeric value."""
    try:
        float(s)
        return True
    except (ValueError, TypeError):
        return False

if __name__ == "__main__":
    test_cases = ["123", "-45.67", "3.14e10", "0x1A", "abc", "12.5.6", "  42  ", ""]
    for case in test_c…

How to Detect if a String Contains Only ASCII in Python

This code defines a function that checks whether every character in a given string is an ASCII character (Unicode code point < 128) and demonstrates it with multiple test cases.

ascii string validation

def is_ascii_only(text: str) -> bool:
    """Return True if all characters in text are ASCII, False otherwise."""
    return all(ord(char) < 128 for char in text)


if __name__ == "__main__":
    # Test cases
    samples = [
        "Hello, world!",
        "Café au lait",
        "日本語テキスト",
        "ASCII only 123",
…

17 0 Open

text-validation strings input-checking

How to Validate Text Input in Python: A Simple Text Processor

A Python function that validates a text string by trimming whitespace, then returns a dictionary with character, word, and sentence counts.

def validate_text(text: str) -> dict:
    """Analyze a text string and return basic validation statistics."""
    stripped = text.strip()
    if not stripped:
        return {
            "valid": False,
            "reason": "Text is empty or only whitespace",
            "characters": 0,
            "words": 0,
    …

11 0 Open

validation strings helper-function

How to Validate Text Strings in Python

Validate strings with a reusable helper that checks type, length limits, and empty string handling.

def is_valid_text(value, min_length=1, max_length=None, allow_empty=False):
    """
    Validate if a value is a string and meets length requirements.
    
    Args:
        value: The value to validate
        min_length: Minimum allowed length (default 1)
        max_length: Maximum allowed length (None = no limit)
…

string isalpha validation

Python String isalpha() Method: Check if String is Alphabetic

This code defines a function that uses Python's str.isalpha() method to determine if a string contains only alphabetic characters, with a demonstration on several test strings.

def is_alphabetic(s):
    return s.isalpha()

if __name__ == "__main__":
    test_strings = ["Hello", "Hello123", "World!", "Python", ""]
    for s in test_strings:
        print(f"{s!r}: {is_alphabetic(s)}")

Validate email format with regex in Python

A Python function using a regex pattern to validate simple email formats, returning True or False for each input.

regex email validation