{"id":9233,"library":"pyprof2calltree","title":"pyprof2calltree","description":"pyprof2calltree is a Python utility that facilitates the visualization of profiling data collected with Python's standard `cProfile` module. It converts `cProfile` output into the calltree format, which can then be graphically analyzed using tools like KCachegrind or QCachegrind. The library, currently at version 1.4.5, is actively maintained with updates primarily focusing on Python version compatibility and minor improvements.","status":"active","version":"1.4.5","language":"en","source_language":"en","source_url":"https://github.com/pwaller/pyprof2calltree/","tags":["profiling","cprofile","kcachegrind","qcachegrind","performance","visualization","developer-tool"],"install":[{"cmd":"pip install pyprof2calltree","lang":"bash","label":"Install with pip"},{"cmd":"sudo apt install kcachegrind pyprof2calltree","lang":"bash","label":"Install on Debian/Ubuntu (includes kcachegrind)"}],"dependencies":[{"reason":"Standard Python profiling module whose output pyprof2calltree processes.","package":"cProfile","optional":false},{"reason":"External graphical tool required to visualize the calltree output. QCachegrind is an alternative for Windows/macOS.","package":"kcachegrind","optional":false}],"imports":[{"symbol":"convert","correct":"from pyprof2calltree import convert"},{"symbol":"visualize","correct":"from pyprof2calltree import visualize"}],"quickstart":{"code":"import cProfile\nimport os\nfrom pyprof2calltree import convert, visualize\n\ndef my_expensive_function():\n    total = 0\n    for i in range(1_000_000):\n        total += i * i\n    return total\n\ndef main_app_logic():\n    _ = my_expensive_function()\n    return \"Done profiling.\"\n\nprofiler = cProfile.Profile()\nprofiler.enable()\nmain_app_logic()\nprofiler.disable()\n\n# Option 1: Save to a file for later viewing\noutput_filename = 'profiling_results.kgrind'\nwith open(output_filename, 'w') as f:\n    convert(profiler.getstats(), f)\nprint(f\"Profiling data saved to {output_filename}. Open with kcachegrind {output_filename}\")\n\n# Option 2: Directly visualize (requires kcachegrind in PATH)\n# try:\n#     visualize(profiler.getstats())\n#     print(\"KCachegrind launched with profiling data.\")\n# except Exception as e:\n#     print(f\"Could not launch KCachegrind directly: {e}. Ensure it's installed and in your PATH.\")\n\n# Example of running a script directly and converting via command line:\n# 1. python -m cProfile -o my_app.prof your_script.py\n# 2. pyprof2calltree -i my_app.prof -o callgrind.out","lang":"python","description":"This quickstart demonstrates how to profile a Python function using `cProfile`, then convert the profiling data to the KCachegrind-compatible calltree format using `pyprof2calltree.convert`. The resulting file can be opened with KCachegrind or QCachegrind for interactive visualization. An alternative `visualize()` function can attempt to launch KCachegrind directly if it's in your system's PATH."},"warnings":[{"fix":"Upgrade to a supported Python version (e.g., Python 3.7+ for latest releases) if encountering compatibility issues.","message":"Older Python versions are no longer officially supported. Version 1.4.4 dropped official support for Python 2.5, 2.6, 3.2, and 3.3. Ensure you are using a compatible Python version (3.4+).","severity":"breaking","affected_versions":">=1.4.4"},{"fix":"Install KCachegrind (e.g., `sudo apt install kcachegrind` on Debian/Ubuntu, `brew install qcachegrind` on macOS) or QCachegrind for your operating system.","message":"pyprof2calltree only *converts* profiling data. You must separately install a visualization tool like `kcachegrind` (Linux) or `qcachegrind` (Windows/macOS) to view the generated `.kgrind` or `.out` files.","severity":"gotcha","affected_versions":"*"},{"fix":"Use `python -m pyprof2calltree` or the installed `pyprof2calltree` command-line script instead of older `eggsecutable` methods.","message":"The `eggsecutable` script for running `pyprof2calltree` was removed in v1.4.5. Rely on `pip install` and the `pyprof2calltree` command-line entry point or direct library imports.","severity":"deprecated","affected_versions":">=1.4.5"}],"env_vars":null,"last_verified":"2026-04-16T00:00:00.000Z","next_check":"2026-07-15T00:00:00.000Z","problems":[{"fix":"Always convert `cProfile` output files (e.g., `my_app.prof`) into the `callgrind` format using `pyprof2calltree` first: `pyprof2calltree -i my_app.prof -o callgrind.out`. Then open `callgrind.out` in KCachegrind.","cause":"KCachegrind cannot directly read the raw output from Python's `cProfile` module. It requires data in the `callgrind` format.","error":"KCachegrind: 'Unknown File Format' error when opening a .prof or .pstat file."},{"fix":"Ensure KCachegrind or QCachegrind is installed and its executable path is included in your system's PATH. On Linux, `sudo apt install kcachegrind` or equivalent is common. On macOS, `brew install qcachegrind` is often used.","cause":"The `kcachegrind` (or `qcachegrind`) executable is not installed on your system or is not located in any directory listed in your system's PATH environment variable.","error":"Could not find kcachegrind. Tried: /usr/bin/kcachegrind, /usr/local/bin/kcachegrind, ..."},{"fix":"When analyzing performance, 'Self' time (or 'tottime' in `cProfile`) often indicates where the function *itself* is spending time, making it crucial for identifying bottlenecks within that specific function's code. 'Incl.' time (or 'cumtime') shows the total time spent in a function *and all its children*, which is useful for understanding the overall cost of a call path. Focus on functions with high 'Self' time for direct optimization within that function.","cause":"Misinterpretation of KCachegrind's 'Self' (tottime) and 'Incl.' (cumtime) metrics. 'Incl.' time includes time spent in child calls, while 'Self' time is exclusive to the function itself.","error":"Profiling data in KCachegrind appears confusing, or a 'fast' function shows high 'Incl.' (Inclusive) time."}]}