depvex 0.1.1

Dependency and environment checker tool

depvex

Depvex is a small Python tool that helps manage a project's dependencies based on the imports used in its Python source code.

It performs three main tasks:

1. Scans Python files in the project and detects third-party imports.
2. Creates or updates the requirements.txt file based on the modules found.
3. Watches the project for changes and re-runs the scan automatically.

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What it does

This tool is especially useful when you want to generate requirements.txt quickly and accurately without writing it manually.

It works like this:

• Reads all .py files in the project
• Extracts imports that are not part of the Python standard library
• Tries to resolve each module into a requirements entry
  • If the module is installed locally, it uses the locally installed version
  • If it is not installed and the network is available, it checks the latest version on PyPI
  • Otherwise, it writes just the module name without a version

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Main features

• Automatic detection of Python imports
• Creation and updating of requirements.txt
• Watch mode support for automatic re-scanning on file changes
• Ignores directories such as .git, pycache, .venv, venv, and node_modules
• Supports version resolution from local installs or PyPI

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Project structure

• cli.py – CLI entry point
• parser.py – Extracts imports from Python code
• resolver.py – Resolves modules into requirements entries
• watcher.py – Watches files for changes

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System requirements

• Python 3.11
• pip
• Internet access (optional, only needed if you want to query PyPI for versions)

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Installation

1) Clone the project

git clone <repository-url>
cd depix

2) Create a virtual environment (recommended)

python3.11 -m venv .venv
source .venv/bin/activate

3) Install the project

python3.11 -m pip install --upgrade pip
python3.11 -m pip install -e .

This will also install the required dependencies, including:

• watchdog
• requests
• typer

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How to run it

Basic mode: one-time scan

If you want to create or update requirements.txt based on the code currently in the project, run:

depvex watch .

This will start watching your code for changes and update requirements.txt whenever a Python file changes.

Running against another path

depvex watch ./my-project

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Example

Suppose you have a Python file like this:

import requests
import os
from pathlib import Path

After running depvex, requirements.txt may be updated to something like:

requests==2.32.3

The exact output depends on the locally installed version or the latest version available on PyPI.

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How watch mode works

In this mode:

• The tool listens for changes in files ending in .py
• When it detects a change, it re-scans the project
• It regenerates requirements.txt

This is especially useful during development when you add or remove imports frequently.

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requirements.txt format

The tool writes entries in the form:

package-name==1.2.3

or, if no version is found:

package-name

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Packaging and publishing to PyPI

The project includes a GitHub Actions workflow that publishes it to PyPI when a tag starting with v is pushed.

To use this, you need:

• a secret named PYPI_TOKEN
• a tag in the following format:

git tag v0.0.1
git push origin v0.0.1

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Important notes

• The tool is based on static analysis of imports, so it does not always detect dynamic imports perfectly.
• If a module is not installed and the network is unavailable, it will write only the module name without a version.
• This is a useful tool for generating an initial requirements.txt, but it is not a full replacement for dependency management tools such as poetry or uv in large projects.

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Common issues

No depvex command found

The most common cause is that the project was not installed with pip install -e .

requirements.txt is not updated

Check whether:

• the file you changed is a .py file
• there is no syntax error in your code
• you are running watch mode from the correct project root

No version is shown for a module

This usually happens when:

• the module is not installed locally
• there is no internet access
• PyPI did not return version information for the module

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Summary

Depvex is a simple and useful tool for generating requirements.txt automatically from Python source code, especially in fast-moving development environments.

If you want to get started quickly, run:

python3.11 -m pip install -e .
depvex watch .