{"library":"mutmut","title":"Mutmut","description":"Mutmut is a mutation testing system for Python, currently at version 3.5.0. It helps identify weaknesses in test suites by making small, automated changes (mutations) to your code and running your tests against them. If tests still pass after a mutation, it indicates a potential gap in the test coverage. It primarily operates as a command-line tool with a focus on ease of use and incremental workflow.","language":"python","status":"active","last_verified":"Sat May 16","install":{"commands":["pip install mutmut"],"cli":{"name":"mutmut","version":"mutmut, version 3.5.0"}},"imports":["mutmut run"],"auth":{"required":false,"env_vars":[]},"quickstart":{"code":"# 1. Install mutmut\n# pip install mutmut\n\n# 2. Navigate to your project directory\n# cd your_project\n\n# 3. (Optional) Configure mutmut via setup.cfg for specific paths or test runners\n# [mutmut]\n# paths_to_mutate=src/\n# runner=python -m unittest discover tests \"*_test.py\"\n# tests_dir=tests/\n\n# 4. Run mutation tests\nprint('Running mutmut run (simulated)')\n# mutmut run\n\n# 5. Browse results (interactive UI)\nprint('Running mutmut browse (simulated)')\n# mutmut browse\n\n# 6. View a non-interactive summary of results\nprint('Running mutmut results (simulated)')\n# mutmut results\n\n# 7. Show a specific mutation (e.g., mutant ID 4)\nprint('Running mutmut show 4 (simulated)')\n# mutmut show 4","lang":"bash","description":"After installation, navigate to your project root. Run `mutmut run` to execute mutation tests. You can then use `mutmut browse` for an interactive review of mutants, `mutmut results` for a summary, or `mutmut show <id>` to inspect a specific mutation. Configuration can be done in `setup.cfg`.","tag":null,"tag_description":null,"last_tested":null,"results":[]},"compatibility":{"tag":null,"tag_description":null,"last_tested":"2026-05-16","installed_version":"3.3.1","pypi_latest":"3.5.0","is_stale":true,"summary":{"python_range":"3.10–3.9","success_rate":100,"avg_install_s":5.2,"avg_import_s":null,"wheel_type":"wheel"},"results":[{"runtime":"python:3.10-alpine","python_version":"3.10","os_libc":"alpine (musl)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":"59.0M"},{"runtime":"python:3.10-slim","python_version":"3.10","os_libc":"slim (glibc)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":5.7,"import_time_s":null,"mem_mb":null,"disk_size":"60M"},{"runtime":"python:3.11-alpine","python_version":"3.11","os_libc":"alpine (musl)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":"66.1M"},{"runtime":"python:3.11-slim","python_version":"3.11","os_libc":"slim (glibc)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":5.1,"import_time_s":null,"mem_mb":null,"disk_size":"67M"},{"runtime":"python:3.12-alpine","python_version":"3.12","os_libc":"alpine (musl)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":"56.8M"},{"runtime":"python:3.12-slim","python_version":"3.12","os_libc":"slim (glibc)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":4.7,"import_time_s":null,"mem_mb":null,"disk_size":"58M"},{"runtime":"python:3.13-alpine","python_version":"3.13","os_libc":"alpine (musl)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":"56.7M"},{"runtime":"python:3.13-slim","python_version":"3.13","os_libc":"slim (glibc)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":4.8,"import_time_s":null,"mem_mb":null,"disk_size":"58M"},{"runtime":"python:3.9-alpine","python_version":"3.9","os_libc":"alpine (musl)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":null,"import_time_s":null,"mem_mb":null,"disk_size":"56.3M"},{"runtime":"python:3.9-slim","python_version":"3.9","os_libc":"slim (glibc)","variant":"mutmut","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"broken","install_time_s":5.6,"import_time_s":null,"mem_mb":null,"disk_size":"57M"}]}}