pip and PyPI: Install, Upgrade, and Manage Packages

pip and PyPI: Install, Upgrade, Uninstall, and Manage Python Packages

Quick Answer

pip installs Python packages. PyPI is the main public package index where many Python packages are published.

Beginner rule: install packages inside a virtual environment and run pip through Python.

Windows:

py -m pip install package-name

macOS:

python3 -m pip install package-name

Last verified: June 9, 2026. Current pip documentation is in the v26.1.x series.

Official Links

• pip documentation: https://pip.pypa.io/en/stable/
• pip installation docs: https://pip.pypa.io/en/stable/installation/
• pip user guide: https://pip.pypa.io/en/stable/user_guide/
• pip configuration docs: https://pip.pypa.io/en/stable/topics/configuration/
• PyPI: https://pypi.org/
• Python packaging guide: https://packaging.python.org/

What You Will Learn

By the end, you should be able to:

• explain what pip does
• explain what PyPI is
• install packages on Windows and macOS
• upgrade and uninstall packages
• create and use requirements.txt
• avoid global package mistakes
• fix common pip errors

1. What pip Does

Python includes a standard library, but many useful tools are separate packages.

Examples:

pandas
matplotlib
requests
jupyterlab
pytest

pip downloads and installs these packages.

2. What PyPI Is

PyPI is the Python Package Index:

https://pypi.org/

When you run:

python -m pip install requests

pip usually downloads requests from PyPI.

3. Check pip Before Installing

Windows PowerShell:

py -m pip --version

If py is unavailable but python works:

python -m pip --version

macOS:

python3 -m pip --version

Linux:

python3 -m pip --version

The output shows both pip version and the Python environment it belongs to.

4. Create A Safe Practice Environment

Do not install learning packages globally by default.

Windows:

mkdir pip-practice
cd pip-practice
py -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install --upgrade pip

macOS:

mkdir pip-practice
cd pip-practice
python3 -m venv .venv
source .venv/bin/activate
python -m pip install --upgrade pip

After activation, python points to the environment's Python.

Check:

python -c "import sys; print(sys.executable)"

The path should contain .venv.

5. Install A Package

Install requests:

python -m pip install requests

Test it:

python -c "import requests; print(requests.__version__)"

Install multiple packages:

python -m pip install pandas matplotlib

6. Install A Specific Version

Sometimes a project needs a specific package version.

python -m pip install "pandas==2.3.0"

Use quotes because some shells treat symbols specially.

For learning, latest stable packages are usually fine. For projects, record versions in requirements.txt.

7. Upgrade A Package

Upgrade one package:

python -m pip install --upgrade requests

Upgrade pip itself:

python -m pip install --upgrade pip

8. Uninstall A Package

python -m pip uninstall requests

pip asks for confirmation.

Use this carefully inside the right environment.

9. List Installed Packages

python -m pip list

Show package details:

python -m pip show pandas

10. Create requirements.txt

requirements.txt records the packages needed to recreate a project.

python -m pip freeze > requirements.txt

Example file:

pandas==2.3.0
matplotlib==3.10.0
requests==2.32.0

Commit requirements.txt to Git. Do not commit .venv.

11. Install From requirements.txt

When someone downloads your project:

Windows:

py -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install -r requirements.txt

macOS:

python3 -m venv .venv
source .venv/bin/activate
python -m pip install -r requirements.txt

12. Common pip Errors And Fixes

pip is not recognized

Use Python to run pip:

py -m pip --version

or:

python3 -m pip --version

No module named pip

Try:

python -m ensurepip --upgrade
python -m pip install --upgrade pip

On Linux, you may need:

sudo apt install python3-pip python3-venv

Permission denied

You are probably installing globally.

Fix it by using a virtual environment:

python -m venv .venv

Then activate it and install again.

externally-managed-environment

This commonly appears on modern Linux distributions when pip tries to modify system-managed Python.

Beginner-safe fix:

python3 -m venv .venv
source .venv/bin/activate
python -m pip install package-name

Avoid --break-system-packages unless you fully understand the risk. It can damage the system Python package boundary.

Network, proxy, timeout, or SSL errors

Common messages:

ReadTimeoutError
ProxyError
SSLError
certificate verify failed

First check whether your internet connection or office/college network blocks package downloads.

Then upgrade pip inside your virtual environment:

python -m pip install --upgrade pip

If your network requires a proxy, ask your network administrator for the proxy URL and use:

python -m pip install --proxy http://user:password@proxy.example.com:8080 package-name

If your organization uses a custom certificate, ask for the certificate file and use:

python -m pip install --cert path/to/company-ca.pem package-name

Avoid random --trusted-host fixes from forums. They weaken package download security and usually hide the real certificate problem.

Package installs but import fails

Check which Python is running your code:

python -c "import sys; print(sys.executable)"

Then install using that same Python:

python -m pip install package-name

13. Windows And macOS Command Comparison

python -m pip install requests
python -c "import requests; print(requests.__version__)"
python -m pip freeze > requirements.txt

FAQ

Should I type pip install or python -m pip install?

Use python -m pip install after activating a virtual environment. On Windows before activation, use py -m pip. On macOS before activation, use python3 -m pip.

Is PyPI safe?

PyPI is the main public package index, but anyone can publish packages. Install known packages, check spelling, and avoid random packages from tutorials you do not trust.

Should I install packages globally?

Avoid it for projects. Use a virtual environment so each project has its own dependencies.

Should I use pip or uv?

Learn pip because it is fundamental. Use uv for faster modern project workflows after you understand pip and virtual environments.

Final Checklist

Windows:

py -m pip --version
py -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install requests
python -c "import requests; print(requests.__version__)"

macOS:

python3 -m pip --version
python3 -m venv .venv
source .venv/bin/activate
python -m pip install requests
python -c "import requests; print(requests.__version__)"

If this works, you can install Python packages safely.

Next in this series: Mastering Python Virtual Environments: Setup and Best Practices →