Package Installation

# Install latest version
pip install package_name

# Install specific version
pip install package_name==1.2.3

# Install version with constraints
pip install "package_name>=1.0,<2.0"
pip install "package_name~=1.2.0"  # Compatible release

# Install multiple packages
pip install package1 package2 package3

# Install from requirements file
pip install -r requirements.txt

# Install from multiple requirements files
pip install -r requirements.txt -r dev-requirements.txt

# Install with constraints
pip install -r requirements.txt -c constraints.txt

# Direct dependencies
requests==2.28.1
django>=4.0,<5.0

# VCS dependencies
git+https://github.com/user/repo.git@v1.0#egg=package_name

# Local dependencies
-e ./local_package
/path/to/local/package.tar.gz

# Index options
--index-url https://pypi.org/simple/
--extra-index-url https://test.pypi.org/simple/

# Installation options
--no-deps
--force-reinstall

# Git repositories
pip install git+https://github.com/user/repo.git
pip install git+https://github.com/user/repo.git@branch_name
pip install git+https://github.com/user/repo.git@tag_name
pip install git+https://github.com/user/repo.git@commit_hash

# With subdirectory
pip install "git+https://github.com/user/repo.git#subdirectory=pkg_dir"

# With specific name
pip install "git+https://github.com/user/repo.git#egg=package_name"

# SSH URLs
pip install git+ssh://git@github.com/user/repo.git

# Other VCS systems
pip install svn+https://svn.example.com/repo/trunk/
pip install hg+https://bitbucket.org/user/repo
pip install bzr+https://launchpad.net/user/repo

# Install from local directory
pip install /path/to/package/

# Install from archive
pip install /path/to/package.tar.gz
pip install /path/to/package.whl

# Editable/development installation
pip install -e /path/to/package/
pip install -e .  # Current directory

# Install from URL
pip install https://example.com/package.tar.gz

# Installation modes
pip install --user package_name           # User installation
pip install --system package_name         # System installation
pip install --target /path/to/dir package_name  # Target directory

# Dependency handling
pip install --no-deps package_name        # Skip dependencies
pip install --force-reinstall package_name  # Force reinstall
pip install --upgrade package_name        # Upgrade to latest
pip install --upgrade-strategy eager package_name  # Upgrade dependencies

# Build options
pip install --no-binary :all: package_name     # Build from source
pip install --only-binary :all: package_name   # Only use wheels
pip install --prefer-binary package_name       # Prefer wheels
pip install --no-build-isolation package_name  # Disable build isolation

# Index options
pip install --index-url https://pypi.org/simple/ package_name
pip install --extra-index-url https://test.pypi.org/simple/ package_name
pip install --trusted-host pypi.org package_name
pip install --find-links /path/to/dir package_name

# Caching
pip install --no-cache-dir package_name   # Disable cache
pip install --cache-dir /path/to/cache package_name  # Custom cache

# Verbosity and output
pip install --verbose package_name        # Verbose output
pip install --quiet package_name          # Minimal output
pip install --progress-bar off package_name  # Disable progress bar

# Using requirements file with hashes
pip install --require-hashes -r requirements.txt

requests==2.28.1 \
    --hash=sha256:7c5599b102feddaa661c826c56ab4fee28bfd17f5abca1ebbe3e7f19d7c97ddf \
    --hash=sha256:8fefa2a1a1365bf5520aac41836fbee479da67864514bdb821f31ce07ce65349

# Index configuration
export PIP_INDEX_URL=https://pypi.org/simple/
export PIP_EXTRA_INDEX_URL=https://test.pypi.org/simple/
export PIP_TRUSTED_HOST=pypi.org

# Installation options
export PIP_USER=1                    # User installation
export PIP_NO_CACHE_DIR=1           # Disable cache
export PIP_REQUIRE_VIRTUALENV=1     # Require virtual environment

# Timeouts and retries
export PIP_TIMEOUT=60
export PIP_RETRIES=3

# Proxy configuration
export PIP_PROXY=http://user:password@proxy.server:port

# Using venv
python -m venv myenv
source myenv/bin/activate  # On Windows: myenv\Scripts\activate
pip install package_name

# Using conda
conda create -n myenv python=3.9
conda activate myenv
pip install package_name

# Require virtual environment
pip install --require-virtualenv package_name
export PIP_REQUIRE_VIRTUALENV=1

import subprocess
import sys

def install_package(package_name, upgrade=False, user=False):
    """Install a Python package using pip."""
    cmd = [sys.executable, '-m', 'pip', 'install']
    
    if upgrade:
        cmd.append('--upgrade')
    if user:
        cmd.append('--user')
        
    cmd.append(package_name)
    
    try:
        subprocess.check_call(cmd)
        print(f"Successfully installed {package_name}")
    except subprocess.CalledProcessError as e:
        print(f"Failed to install {package_name}: {e}")
        raise

def install_requirements(requirements_file):
    """Install packages from requirements file."""
    cmd = [sys.executable, '-m', 'pip', 'install', '-r', requirements_file]
    
    try:
        subprocess.check_call(cmd)
        print(f"Successfully installed from {requirements_file}")
    except subprocess.CalledProcessError as e:
        print(f"Failed to install from {requirements_file}: {e}")
        raise

# Usage examples
install_package('requests')
install_package('django', upgrade=True)
install_requirements('requirements.txt')