Import Profile Viewer
A VS Code extension for viewing Python module import profiling results as an interactive, collapsible tree — right inside the editor.
When you run a Python script with the -X importtime flag, Python prints a detailed breakdown of every module import and how long each one takes. This extension parses that output and presents it as a clean, searchable tree view so you can quickly spot slow imports.
Features
- Collapsible tree view — expand and collapse modules to explore the import hierarchy
- Color-coded timing indicators — modules are marked with colored dots based on cumulative import time:
- 🟢 Green: < 2 ms
- 🟡 Yellow: 2–10 ms
- 🟠 Orange: 10–50 ms
- 🔴 Red: > 50 ms
- Self & cumulative time — see both the module's own import time and the total time including sub-imports
- Search / filter — quickly find any module by name
- Supports raw text and JSON — load the original
-X importtime output or a pre-parsed JSON tree
How to Generate an Import Profile
Run your Python script with the -X importtime flag and redirect stderr to a file:
python -X importtime your_script.py 2> import_profile.txt
This produces a file like:
import time: self [us] | cumulative | imported package
import time: 170 | 170 | _io
import time: 30 | 30 | marshal
import time: 514 | 924 | _frozen_importlib_external
...
How to Open the Result File
- In VS Code, open the Explorer panel (file tree)
- Right-click on your
import_profile.txt (or .json / .log) file
- Select "Open with Import Profile Viewer" from the context menu
- The profiling tree opens in an editor tab
You can also use the Command Palette (Ctrl+Shift+P / Cmd+Shift+P):
- Type "Open with Import Profile Viewer"
- Pick your profile file from the file dialog
Example
Given a profile from python -X importtime, the viewer shows:
▶ numpy (self: 1.2 ms | cumul: 156.3 ms) 🔴
▶ numpy.core (self: 1.2 ms | cumul: 49.9 ms) 🟠
▶ numpy.core.multiarray ...
▶ numpy.core.numeric ...
▶ numpy.lib (self: 1.0 ms | cumul: 30.8 ms) 🟠
▶ numpy.fft (self: 0.6 ms | cumul: 2.9 ms) 🟡
▶ pandas (self: 3.8 ms | cumul: 234.5 ms) 🔴
▶ sqlite3 (self: 15.7 ms | cumul: 30.4 ms) 🟠
Requirements
- VS Code 1.80.0 or later
- A Python import profile file generated with
python -X importtime
License
MIT
