Command Line Interface¶

feu provides a command-line interface (CLI) for package management tasks. To use the CLI, you need to install the optional cli dependency:

pip install 'feu[cli]'

Available Commands¶

The CLI provides three main commands:

install - Install a package with version compatibility checks
find-closest-version - Find the closest valid version for a package
check-valid-version - Check if a package version is valid for a Python version

Install Command¶

Install a package with automatic version compatibility handling for your Python environment.

Syntax¶

python -m feu install [OPTIONS]

Options¶

-n, --pkg-name TEXT - Package name (required)
-v, --pkg-version TEXT - Package version (required)
-e, --pkg-extras TEXT - Package extra dependencies (optional, comma-separated)
-i, --installer-name TEXT - Installer name (default: "pip")
-a, --installer-args TEXT - Installer arguments (optional)

Examples¶

Install NumPy version 2.0.2:

python -m feu install --pkg-name=numpy --pkg-version=2.0.2

Install NumPy with specific extras:

python -m feu install --pkg-name=numpy --pkg-version=2.0.2 --pkg-extras=dev,doc

Install with custom installer arguments:

python -m feu install \
  --pkg-name=numpy \
  --pkg-version=2.0.2 \
  --installer-name=pip \
  --installer-args="--upgrade --no-cache-dir"

Find Closest Version Command¶

Find the closest valid version of a package for a specific Python version.

Syntax¶

python -m feu find-closest-version [OPTIONS]

Options¶

-n, --pkg-name TEXT - Package name (required)
-v, --pkg-version TEXT - Package version to check (required)
-p, --python-version TEXT - Python version (required, e.g., "3.10", "3.11")

Examples¶

Find the closest valid NumPy version for Python 3.10:

python -m feu find-closest-version \
  --pkg-name=numpy \
  --pkg-version=2.0.2 \
  --python-version=3.10

Output:

2.0.2

Check what version would be used for an older NumPy version on Python 3.11:

python -m feu find-closest-version \
  --pkg-name=numpy \
  --pkg-version=1.0.0 \
  --python-version=3.11

Output:

1.23.2

This shows that NumPy 1.0.0 is too old for Python 3.11, so the minimum supported version (1.23.2) would be used instead.

Check Valid Version Command¶

Check if a specific package version is valid for a given Python version.

Syntax¶

python -m feu check-valid-version [OPTIONS]

Options¶

-n, --pkg-name TEXT - Package name (required)
-v, --pkg-version TEXT - Package version to check (required)
-p, --python-version TEXT - Python version (required, e.g., "3.10", "3.11")

Examples¶

Check if NumPy 2.0.2 is valid for Python 3.10:

python -m feu check-valid-version \
  --pkg-name=numpy \
  --pkg-version=2.0.2 \
  --python-version=3.10

Output:

True

Check if NumPy 1.0.0 is valid for Python 3.11:

python -m feu check-valid-version \
  --pkg-name=numpy \
  --pkg-version=1.0.0 \
  --python-version=3.11

Output:

False

Practical Workflows¶

Workflow 1: Verify Before Install¶

Before installing a package, check if the version is compatible:

# Check compatibility
VALID=$(python -m feu check-valid-version \
  --pkg-name=numpy \
  --pkg-version=2.0.2 \
  --python-version=3.10)

if [ "$VALID" = "True" ]; then
  echo "Version is compatible, proceeding with installation..."
  python -m feu install --pkg-name=numpy --pkg-version=2.0.2
else
  echo "Version is not compatible, finding closest version..."
  VERSION=$(python -m feu find-closest-version \
    --pkg-name=numpy \
    --pkg-version=2.0.2 \
    --python-version=3.10)
  echo "Installing version $VERSION instead"
  python -m feu install --pkg-name=numpy --pkg-version=$VERSION
fi

Workflow 2: Batch Installation¶

Install multiple packages with compatibility checks:

#!/bin/bash

PACKAGES=(
  "numpy:2.0.2"
  "pandas:2.0.0"
  "scipy:1.10.0"
)

PYTHON_VERSION="3.10"

for pkg in "${PACKAGES[@]}"; do
  IFS=':' read -r name version <<< "$pkg"

  echo "Processing $name $version..."

  closest=$(python -m feu find-closest-version \
    --pkg-name=$name \
    --pkg-version=$version \
    --python-version=$PYTHON_VERSION)

  echo "Installing $name $closest"
  python -m feu install --pkg-name=$name --pkg-version=$closest
done

Workflow 3: CI/CD Integration¶

Use in continuous integration to ensure compatible versions:

# .github/workflows/install-deps.yml
name: Install Dependencies

on: [push, pull_request]

jobs:
  install:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: ['3.10', '3.11', '3.12', '3.13']

    steps:
      - uses: actions/checkout@v4

      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: ${{ matrix.python-version }}

      - name: Install feu
        run: pip install 'feu[cli]'

      - name: Install numpy with version check
        run: |
          python -m feu install \
            --pkg-name=numpy \
            --pkg-version=2.0.2

Tips and Best Practices¶

Always specify Python version: When using find-closest-version or check-valid-version, make sure to specify the correct Python version you're targeting.
Use extras for optional dependencies: When installing packages with optional features, use the --pkg-extras flag to include them.
Combine with pip options: Use --installer-args to pass additional pip options like --upgrade, --no-deps, or --no-cache-dir.
Script automation: The CLI commands are designed to be easily integrated into shell scripts and CI/CD pipelines.
Version checking: Always use check-valid-version before attempting installation in production environments to avoid runtime errors.