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Strings & text

Format, split, join, parse, and clean text — everyday Python string patterns.

5 matches
Strings & text easy

Find Most Frequent Character in a String in Python

Count character frequencies in a Python string using a dictionary and return the character that appears most often with a max() key function.

string dictionary counting
Python
def most_frequent_char(s: str) -> str:
    if not s:
        return ""
    
    char_count = {}
    for ch in s:
        char_count[ch] = char_count.get(ch, 0) + 1
    
    max_char = max(char_count, key=char_count.get)
    return max_char

if __name__ == "__main__":
    text = "programming"
    result = most_frequent…
12 0 Open
Strings & text easy

How to Format Strings with Named Placeholders in Python

Format a template string using named placeholders with the str.format() method and a dictionary.

string format placeholders
Python
def format_named(template, data):
    """Format a template string using named placeholders."""
    return template.format(**data)


if __name__ == "__main__":
    template = "Hello {name}, you are {age} years old and live in {city}."
    data = {"name": "Alice", "age": 30, "city": "London"}
    result = format_named(t…
15 0 Open
Strings & text easy

How to Group Data by Category in Python

Group a list of (category, value) tuples into a dictionary of lists using the setdefault method.

grouping dictionaries setdefault
Python
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…
12 0 Open
Strings & text easy

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.

text-validation strings input-checking
Python
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
Strings & text easy

How to parse key=value pairs in Python

Parse a single line of key=value pairs separated by a delimiter into a Python dictionary.

parsing key-value dictionary
Python
def parse_key_value_pairs(line: str, delimiter: str = "&") -> dict:
    """Parse a single line of key=value pairs into a dictionary."""
    pairs = {}
    for token in line.split(delimiter):
        if not token.strip():
            continue
        key, _, value = token.partition("=")
        pairs[key.strip()] = val…
11 0 Open

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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.