Python Time & Space Complexity Reference¶
Welcome to the comprehensive guide for Python operation complexity. This resource documents the time and space complexity of Python's built-in operations, standard library functions, and their behavior across different Python versions and implementations.
Quick Start¶
- Built-in Types - Complexity analysis for lists, dicts, sets, strings, and tuples
- Standard Library - Modules like collections, heapq, bisect, and more
- Implementations - CPython, PyPy, Jython, and other implementation details
- Versions - Changes and optimizations by Python version
Why This Matters¶
Understanding complexity helps you:
- Write performant Python code
- Choose the right data structure for your use case
- Predict how your code scales with larger inputs
- Optimize algorithms effectively
Example: List Operations¶
The complexity of list operations varies:
| Operation | Time Complexity | Space |
|---|---|---|
append() |
O(1) amortized | - |
insert(0, x) |
O(n) | - |
pop() |
O(1) | - |
pop(0) |
O(n) | - |
in (search) |
O(n) | - |
sort() |
O(n log n) | O(n) |
See Built-in Types for detailed analysis.
How to Use This Guide¶
- Search - Use the search bar to find specific operations
- Browse - Navigate by type or module
- Filter - Select Python version or implementation
- Check Notes - Read implementation-specific considerations
Coverage¶
- Python Versions: 3.9-3.14
- Implementations: CPython, PyPy, Jython, IronPython
- Operations: Over 100+ built-in and stdlib operations
- Updates: Regularly updated with new Python releases
Why Trust This Documentation?¶
This documentation has been reviewed and refined through 100+ commits by multiple AI coding agents (Amp, Claude, Antigravity) working alongside human contributors. Each agent brings different perspectives and catches different issues, resulting in thorough cross-validation.
It's also fully open source—anyone can review the content, file issues, or submit improvements. All sources are cited, and claims are based on official Python documentation and CPython source code.
Contributing¶
Found an inaccuracy or want to add content? See our Contributing Guidelines.
Sources¶
- Python Official Documentation
- TimeComplexity Wiki
- CPython source code and implementation details
- Performance testing and benchmarking
Disclaimer: While we strive for accuracy, complexity characteristics may vary based on specific contexts, input sizes, and implementation details. Always verify with benchmarks for performance-critical code.