pip - Package Installer

Learn how to use pip, Python's package installer, to install, manage, and work with third-party packages.

By Ali Berro

January 9, 2026 5 min read Section 2

From: Python Fundamentals: From Zero to Hero

python pip packages installation

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pip - Package Installer

pip (Pip Installs Packages) is Python’s standard package manager. It allows you to install and manage third-party packages from the Python Package Index (PyPI) and other sources.

What is pip?

pip is a command-line tool that comes with Python (version 3.4+) and allows you to:

Install packages from PyPI
Uninstall packages
List installed packages
Show package information
Search for packages
Manage package versions

Checking pip Installation

First, verify that pip is installed:

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pip --version
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# or
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pip3 --version

If pip is not installed, you can install it using:

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python -m ensurepip --upgrade

Basic pip Commands

Install a Package

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pip install package_name

Example:

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pip install requests
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pip install numpy pandas matplotlib

Install Specific Version

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pip install package_name==version
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pip install requests==2.28.0

Install from Version Range

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pip install "package_name>=2.0,<3.0"
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pip install "requests>=2.25.0,<3.0.0"

Upgrade a Package

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pip install --upgrade package_name
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# or
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pip install -U package_name

Uninstall a Package

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pip uninstall package_name

List Installed Packages

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pip list

Show Package Information

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pip show package_name

Search for Packages

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pip search query

Note
The pip search command has been disabled on PyPI. Use the web interface at https://pypi.org/ to search for packages.

Installing from Requirements File

Create a requirements.txt file:

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requests==2.28.0
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numpy>=1.20.0
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pandas==1.5.0
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matplotlib

Install all packages from the file:

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pip install -r requirements.txt

Common pip Options

Install to User Directory

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pip install --user package_name

Install in Development Mode

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pip install -e .

Ignore Installed Packages

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pip install --ignore-installed package_name

No Cache

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pip install --no-cache-dir package_name

Verbose Output

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pip install -v package_name

Popular Python Packages

Here are some commonly used packages:

Data Science

NumPy: Numerical computing
Pandas: Data manipulation and analysis
Matplotlib: Plotting and visualization
SciPy: Scientific computing

Web Development

Flask: Lightweight web framework
Django: Full-featured web framework
Requests: HTTP library

Machine Learning

scikit-learn: Machine learning library
TensorFlow: Deep learning framework
PyTorch: Deep learning framework

Utilities

Pillow: Image processing
BeautifulSoup4: HTML/XML parsing
python-dotenv: Environment variables

Installing Packages

Example: Installing NumPy

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pip install numpy

Then use it in Python:

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import numpy as np
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# Create an array
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arr = np.array([1, 2, 3, 4, 5])
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print(arr)  # [1 2 3 4 5]
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# Perform operations
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print(arr.mean())  # 3.0
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print(arr.sum())   # 15

Example: Installing Requests

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pip install requests

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import requests
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# Make HTTP request
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response = requests.get('https://api.github.com')
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print(response.status_code)  # 200

Managing Package Versions

Check Installed Version

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pip show package_name

Install Latest Version

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pip install --upgrade package_name

Install Specific Version

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pip install package_name==2.1.0

Downgrade Package

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pip install package_name==1.9.0

Requirements Files

Creating requirements.txt

Generate a requirements file from installed packages:

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pip freeze > requirements.txt

This creates a file with all installed packages and their versions:

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numpy==1.24.0
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pandas==1.5.3
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matplotlib==3.6.2
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requests==2.28.0

Installing from requirements.txt

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pip install -r requirements.txt

Virtual Environments and pip

It’s recommended to use pip within virtual environments:

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# Create virtual environment
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python -m venv myenv
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# Activate (Windows)
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myenv\Scripts\activate
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# Activate (Linux/Mac)
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source myenv/bin/activate
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# Install packages
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pip install package_name

Troubleshooting pip

Upgrade pip

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python -m pip install --upgrade pip

Clear pip Cache

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pip cache purge

Check pip Configuration

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pip config list

Install from Alternative Source

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pip install -i https://pypi.org/simple/ package_name

pip Best Practices

Use virtual environments: Isolate project dependencies
Pin versions: Use requirements.txt with specific versions
Keep pip updated: Regularly upgrade pip itself
Use requirements files: Track all dependencies
Test after installation: Verify packages work correctly

Exercises

Exercise 1: Understanding pip Commands

Write the pip command to install the requests package. Then write code to import requests and make a simple GET request to ‘https://httpbin.org/get’, printing the status code.

Answer:

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# Command: pip install requests
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import requests
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response = requests.get('https://httpbin.org/get')
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print(response.status_code)

Exercise 2: Requirements File

Create a requirements.txt content with numpy version 1.24.0 and pandas version 1.5.3. Then write the pip command to install from this file.

Answer:

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# requirements.txt content:
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# numpy==1.24.0
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# pandas==1.5.3
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# Command: pip install -r requirements.txt
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print("requirements.txt created")
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print("Command: pip install -r requirements.txt")

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Section 57 of 61

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Table of Contents

Table of Contents

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Exercise 1: Understanding pip Commands

Exercise 2: Requirements File

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