Multiple spaces
Input
normalize_whitespace(' Hello world ')
Output
Hello world
All extra spaces are collapsed to single spaces and trimmed.
Full lesson preview
Normalize whitespace in a string
Collapse all runs of whitespace into single spaces and trim ends.
Python practice10 minString PatternsBeginnerLast updated March 18, 2026
Problem statement
Write normalize_whitespace(s) that returns a new string where every contiguous run of whitespace characters (spaces, tabs, newlines, etc.) is replaced by a single ASCII space (' '), and leading/trailing whitespace is removed. If the input contains only whitespace, return an empty string.
Task
Implement a function that normalizes any whitespace sequences into single spaces and trims leading/trailing whitespace.
Examples
Mixed whitespace
Input
normalize_whitespace('line1\nline2\tline3')
Output
line1 line2 line3
Newlines and tabs are converted to single spaces between tokens.
Input format
A call to normalize_whitespace(s) where s is a string.
Output format
The normalized string returned.
Constraints
Do not import external libraries; use built-in string methods. Aim for a solution that handles arbitrary Unicode whitespace correctly via built-in behavior.
Samples
Sample 1
Input
normalize_whitespace('already clean')
Output
already clean
No change needed.