What is pip

Introduction

pip is Python's package installer. It lets you download and install third-party libraries from the Python Package Index (PyPI) — a public repository of over 500,000 packages.

Basic Usage

# Install a package
pip install requests

# Install a specific version
pip install requests==2.31.0

# Install the latest compatible version within a range
pip install "requests>=2.28,<3"

# Upgrade an installed package
pip install --upgrade requests

# Uninstall a package
pip uninstall requests

# List installed packages
pip list

# Show details about a specific package
pip show requests

Searching for Packages

Rather than searching from the command line (the search command was removed), go to pypi.org and search there. Check:

• How recently it was updated
• How many downloads it has
• Whether it has a linked GitHub repo with active maintenance

pip and Virtual Environments

Always activate your virtual environment before running pip install. Packages installed without an active environment go into the system Python, which can cause version conflicts between projects.

# Activate first
source .venv/bin/activate      # macOS/Linux
.venv\Scripts\activate         # Windows

# Then install
pip install requests

Grade 8 covers virtual environments in detail.

Commonly Used Packages in Data Roles

Package	Use
pandas	Tabular data manipulation
polars	Fast DataFrames (modern alternative to pandas)
requests	HTTP requests and APIs
sqlalchemy	Database connections and ORM
boto3	AWS SDK
pydantic	Data validation
pytest	Testing
black	Code formatting

Practice Exercises

• Run pip list and note which packages are currently installed.
• Install the requests package and verify it appears in pip list.
• Run pip show requests and note the version, author, and homepage.
• Uninstall requests and confirm it no longer appears in pip list.