Strings & text
Format, split, join, parse, and clean text — everyday Python string patterns.
Automatically Detect Weak Passwords from Large Password Lists in Python
This Python script identifies weak passwords from a list by checking length, common patterns, sequential characters, and uniform characters, returning those that fail the security checks.
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…
How to Check and Manipulate Strings in Python
Demonstrates core string inspection and transformation methods like case conversion, trimming, splitting, and membership checks on a sample string.
text = " Hello, Python Learners! "
print(f"Original: '{text}'")
print(f"Lowercase: '{text.lower()}'")
print(f"Uppercase: '{text.upper()}'")
print(f"Title case: '{text.title()}'")
print(f"Stripped: '{text.strip()}'")
print(f"Length: {len(text)}")
print(f"Replace: '{text.replace('Python', 'Programming')}'")
print(f"S…
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.
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",
…
How to Extract Digits Only from a String in Python
This code uses a regular expression to remove all non-digit characters from a mixed string, returning only the digits.
import re
def extract_digits(text):
"""Return only the digits from the given text as a string."""
return re.sub(r'\D', '', text)
if __name__ == "__main__":
mixed = "abc123def456!@#789"
result = extract_digits(mixed)
print(result)
How to Format Text in Python (Beginner's Guide)
This beginner-friendly Python script demonstrates text formatting basics: stripping whitespace, converting to title case, replacing substrings, splitting into words, and generating a snippet.
text = " hello world, welcome to python skillset! "
cleaned = text.strip()
title_cased = cleaned.title()
replaced = title_cased.replace("Python", "PYTHON")
words = replaced.split()
word_count = len(words)
first_three = " ".join(words[:3])
snippet = first_three + "..."
print("Original:", repr(text))
print("Stripped:"…
How to Join Multiline Text with a Semicolon Separator in Python
This code joins non-empty lines of multiline text into a single string separated by semicolons, stripping leading and trailing whitespace from each line.
def join_multiline_text_with_semicolon(text):
"""Join lines of multiline text with a semicolon separator."""
lines = [line.strip() for line in text.splitlines() if line.strip()]
return "; ".join(lines)
if __name__ == "__main__":
sample_text = """First line
Second line
Third line"""
result = join_…
How to Mask Credit Card Middle Digits in Python
Mask the middle digits of credit card numbers in a string, keeping only the first 8 and last 4 digits, using regular expressions.
import re
def mask_credit_card(text: str) -> str:
pattern = re.compile(r'(\d{4}[-\s]?)(\d{4}[-\s]?)(\d{4}[-\s]?)(\d{4})')
return pattern.sub(lambda m: m.group(1) + m.group(2) + '****' + m.group(4), text)
if __name__ == "__main__":
sample = "Card: 1234-5678-9012-3456 and 1111 2222 3333 4444"
print(mas…
How to Merge Strings in Python
Merge multiple strings or a list of text lines into one string with a custom separator
def merge_strings(*parts, separator=" "):
"""Merge multiple string parts into one string with a separator."""
return separator.join(parts)
def merge_text_lines(lines, separator="\n"):
"""Merge a list of text lines into a single string."""
return separator.join(lines)
if __name__ == "__main__":
…
How to Process Lines of Text in Python
Strip whitespace, split a multi-line string, count words per line, and print structured summaries using basic string methods and loops.
text = """ Python is great!
Coding is fun.
Python skills help you grow. """
lines = text.strip().splitlines()
line_count = len(lines)
processed = []
for line in lines:
stripped = line.strip()
word_count = len(stripped.split())
processed.append({
"original": line,
"stripped": stripp…
How to Process Text in Python
This code processes multiline text by splitting lines, stripping whitespace, counting words and characters, and converting to lowercase.
def process_text(text):
lines = text.split("\n")
clean_lines = []
for line in lines:
stripped = line.strip()
if stripped:
tokens = stripped.split()
title_case = stripped.lower()
clean_lines.append({
"raw": stripped,
"word_c…
How to Remove HTML Tags in Python with Regex
Strips all HTML tags from a string using a regular expression and cleans extra whitespace.
import re
def remove_html_tags(text: str) -> str:
"""Remove all HTML tags from the given text using regex."""
# Remove opening and closing tags
clean = re.sub(r'<[^>]+>', '', text)
# Remove any extra whitespace left behind
clean = re.sub(r'\s+', ' ', clean).strip()
return clean
if __name__ ==…
How to Replace Multiple Spaces with a Single Space in Python
This snippet uses the `re` module to collapse runs of consecutive spaces in a string into a single space, cleaning up whitespace.
import re
def collapse_spaces(text):
"""Replace multiple consecutive spaces with a single space."""
return re.sub(r' +', ' ', text)
if __name__ == "__main__":
sample = "This has multiple spaces between words."
result = collapse_spaces(sample)
print(f"Original: '{sample}'")
print(f"Co…
How to Split Lines and Strip Blank Lines in Python
Split a multiline string into non-empty lines and strip surrounding whitespace using a list comprehension.
import sys
def split_and_strip(text):
"""Split text into non-blank lines, stripping whitespace."""
return [line.strip() for line in text.splitlines() if line.strip()]
if __name__ == "__main__":
sample_text = """ First line
Second line
Third line """
result = split_and_strip(…
How to Split Strings in Python (Beginner-Friendly)
Split Python strings by a delimiter into lists, plus a cleanup variant that strips whitespace and filters empty parts.
def split_text(text, delimiter=" "):
"""Split a string by a delimiter and return a list of parts."""
return text.split(delimiter)
def split_text_with_cleanup(text, delimiter=" "):
"""Split a string, stripping whitespace and filtering empty parts."""
parts = text.split(delimiter)
cleaned = [part.s…
How to Strip Whitespace in Python
This code demonstrates how to remove leading and trailing whitespace from a string using the built-in strip() method.
def strip_whitespace(text: str) -> str:
return text.strip()
if __name__ == "__main__":
sample = " Hello, world! "
result = strip_whitespace(sample)
print(f"Original: '{sample}'")
print(f"Stripped: '{result}'")
How to Transform Text in Python with a Helper Function
Build a simple Python helper to strip extra whitespace and convert text to upper, lower, or title case.
def transform_text(text, upper=False, lower=False, strip_whitespace=False, title_case=False):
"""Apply common string transformations for beginners."""
result = text
if strip_whitespace:
result = " ".join(result.split())
if upper and lower:
raise ValueError("Cannot apply both upper and…
How to Truncate a String with Ellipsis in Python
A function that shortens text to a maximum length and appends an ellipsis when truncation occurs, handling edge cases.
def truncate_with_ellipsis(text: str, max_length: int) -> str:
"""Truncate text to max_length, appending ellipsis if truncated."""
if len(text) <= max_length:
return text
if max_length <= 3:
return text[:max_length]
return text[: max_length - 3] + "..."
if __name__ == "__main__":
t…
How to build a text helper in Python for beginners
This code provides easy-to-use functions for cleaning text, removing punctuation, counting word frequencies, and summarizing strings — perfect for beginners.
def clean_text(text: str) -> str:
"""Clean and normalize a text string."""
text = text.strip()
text = text.replace(" ", " ")
text = text.capitalize()
text = text.replace(".", ".")
return text
def remove_punctuation(text: str) -> str:
"""Remove common punctuation marks from a string."""
…
Python String Helper Functions for Beginners
A set of beginner-friendly Python functions that count words, reverse text, convert to title case, strip punctuation, and compute character frequency from a string.
def count_words(text):
"""Count the number of words in a string."""
return len(text.split())
def reverse_text(text):
"""Reverse the entire string."""
return text[::-1]
def title_case(text):
"""Capitalize the first letter of each word."""
return text.title()
def remove_punctuation(text):
…
Python: Replace Spaces with Hyphens for Slug
Transform a string by stripping surrounding whitespace and replacing each space with a hyphen to create a simple slug.
def slugify(text):
return text.strip().replace(" ", "-")
if __name__ == "__main__":
title = "Hello World Python Example"
result = slugify(title)
print(result)
String helpers in Python: stats, reverse, and remove vowels
Three beginner-friendly Python functions compute text statistics, reverse word order, and strip vowels from a string.
def text_stats(text: str) -> dict:
"""Return basic statistics for a given text string."""
words = text.split()
return {
"characters": len(text),
"words": len(words),
"sentences": text.count(".") + text.count("!") + text.count("?"),
"uppercase": sum(1 for c in text if c.isupp…
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This page collects strings & text snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.
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Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.