Strings & text
Format, split, join, parse, and clean text — everyday Python string patterns.
Build CSV row from Python list with proper quoting
Converts a list of fields into a properly quoted CSV row string using the csv module.
import csv
import io
def build_csv_row(fields):
output = io.StringIO()
writer = csv.writer(output)
writer.writerow(fields)
return output.getvalue().rstrip("\r\n")
if __name__ == "__main__":
fields = ["Alice", "Smith", "123 Main St, Apt 4B", "alice@example.com"]
print(build_csv_row(fields))Extract Data from Strings in Python: Beginner's Guide
A beginner-friendly helper that splits a comma-separated string into a list, shows word count, and extracts the first and last words using Python's split() and join() methods.
text = "python,string,extract,beginner"
words = text.split(",")
print("Full text:", text)
print("Word count:", len(words))
print("First word:", words[0])
print("Last word:", words[-1])
joined = " | ".join(words)
print("Joined with separator:", joined)Extract URLs from text with regex in Python
Uses a regular expression to find and print HTTP/HTTPS URLs from a block of text.
import re
text = """
Visit https://www.example.com for docs.
Contact support@mysite.org.
Check http://localhost:8000/api or ftp://files.example.net.
"""
url_pattern = r'https?://[^\s]+'
urls = re.findall(url_pattern, text)
for url in urls:
print(url)Find the Longest Word in a Sentence in Python
Splits a sentence into words and returns the longest one using the built-in max() function with len as the key.
def find_longest_word(sentence: str) -> str:
words = sentence.split()
if not words:
return ""
return max(words, key=len)
if __name__ == "__main__":
test_sentence = "The quick brown fox jumps over the lazy dog"
longest = find_longest_word(test_sentence)
print(f"Longest word: '{longest}'…How to Align Text in Two Columns with ljust in Python
Format pairs of strings into two aligned columns using ljust padding.
items = [
("apple", "red"),
("banana", "yellow"),
("cherry", "dark red"),
("date", "brown")
]
col1_width = max(len(name) for name, _ in items) + 2
for name, color in items:
print(name.ljust(col1_width) + color)How to Build a Basic Text Processor in Python
Split text into sentences, count words, find the longest word, and convert text to uppercase — all with pure Python string methods.
text = """The quick brown fox jumps over the lazy dog.
Python is a powerful programming language.
Keep practicing every single day!"""
sentences = text.split(". ")
word_count = 0
longest_word = ""
for sentence in sentences:
words = sentence.split()
word_count += len(words)
for word in words:
clea…How to Build a Text Processor in Python
This code defines functions to count words, sentences, and find the longest word in a text, then prints basic statistics like uppercase and lowercase versions.
def count_words(text):
return len(text.split())
def count_sentences(text):
sentence_endings = ".!?"
count = 0
for char in text:
if char in sentence_endings:
count += 1
return count
def longest_word(text):
words = text.split()
if not words:
return ""
retur…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 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 Group Data by Category in Python
Group a list of (category, value) tuples into a dictionary of lists using the setdefault method.
def group_by_category(data):
"""Group list of (category, value) tuples into dictionaries of lists."""
groups = {}
for category, value in data:
groups.setdefault(category, []).append(value)
return groups
if __name__ == "__main__":
items = [
("fruit", "apple"),
("veg", "carro…How to Join List of Words into a Sentence in Python
Concatenate a list of strings into a single sentence with spaces using the Python string join() method.
words = ["Hello", "world", "this", "is", "Python"]
sentence = " ".join(words)
print(sentence)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 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 Merge Two Strings Character by Character in Python
Interleave characters from two strings, appending any surplus characters from the longer string at the end.
def merge_texts(left: str, right: str) -> str:
"""
Merges two strings by interleaving their characters:
first char from left, first from right, then second from left,
second from right, and so on. If one string is longer, the
remaining characters are appended at the end.
Example:
merge_tex…How to Parse and Clean Text in Python
This code defines three helper functions to parse text into lowercase words, count unique word frequencies, and clean text by removing punctuation and extra whitespace.
def extract_words(text: str) -> list[str]:
"""Return a list of lowercase words from the given text."""
return [word.lower() for word in text.split() if word.isalpha()]
def count_unique_words(text: str) -> dict[str, int]:
"""Return a dictionary with unique words and their frequencies."""
words = extra…How to Partition a String on the First Delimiter in Python
Split a string into a tuple of (before, delimiter, after) at the first occurrence of a given delimiter, using a custom function or the built-in str.partition.
def partition_string(s, delimiter):
"""Split string into (before, delimiter, after) on the first occurrence."""
for i, ch in enumerate(s):
if ch == delimiter:
return s[:i], ch, s[i+1:]
return s, "", ""
if __name__ == "__main__":
# Single-character delimiter
s1 = "hello,world,h…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 Remove Duplicate Adjacent Spaces in Python
This Python function collapses any sequence of two or more adjacent spaces into a single space, preserving all other characters.
def remove_duplicate_adjacent_spaces(text):
"""Replace sequences of 2+ spaces with a single space."""
result = []
prev_was_space = False
for char in text:
if char == " ":
if not prev_was_space:
result.append(char)
prev_was_space = True
else:
…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 Round Numbers with f-strings in Python
Round numbers directly inside f-string expressions using the built-in round() function for clean, readable output formatting.
def main():
# Values to format with expression-based rounding
price = 19.995
tax_rate = 0.0825
distance = 1234.56789
# Round inside the f-string expression using round()
print(f"Price rounded to cents: ${round(price, 2)}")
# Combine rounding with arithmetic inside the expression
total…How to Slugify a String in Python
Convert any text into a URL-friendly slug using the standard library's unicodedata and re modules.
import re
import unicodedata
def slugify(text):
text = unicodedata.normalize('NFKD', text)
text = text.encode('ascii', 'ignore').decode('ascii')
text = re.sub(r'[^\w\s-]', '', text).strip().lower()
text = re.sub(r'[-\s]+', '-', text)
return text
if __name__ == "__main__":
title = "Hello, Worl…How to Sort Text in Python with a Simple Helper Function
A compact helper function that sorts a list of strings or splits a string into words and sorts them alphabetically, with optional reverse ordering.
def sort_text(data, reverse=False):
"""
Sort a list of strings (or a single string split into words) alphabetically.
"""
if isinstance(data, str):
words = data.split()
else:
words = [str(item) for item in data]
return sorted(words, reverse=reverse)
if __name__ == "__main__":
…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…Browse by section
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Strings & text — Python code examples
What you will find here
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.
Samples vs tutorials and challenges
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.