Install Python Package into Different Directory using pip

Python's ecosystem has libraries and tools that help developers build powerful applications. The pip package manager simplifies the installation of Python packages from the Python Package Index (PyPI), typically placing them in the default system-wide site-packages directory.

However, there are instances when installing packages into different directories is beneficial, particularly for managing dependencies more effectively and avoiding conflicts. In this article, we'll explore several methods to install Python packages into a different directory using pip.

• Using the ??target Option with pip
• Setting the PYTHONPATH Environment Variable
• Using a Virtual Environment

Using the ??target Option with pip

The simplest way to install a package into a specific directory is by using the --target option in your pip command. This method installs the specified package and its dependencies into the designated directory.

Syntax

Open your terminal or command prompt. Run the following command:

export PYTHONPATH=/path/to/custom_directory:$PYTHONPATH
pip install package_name --target /path/to/custom_directory

Example

In the following example, we are going to install the 'requests' package into a custom directory, 'my_packages', using the --target option set to '~/my_packages'. This directs Pip to install the package files into that specific location. After execution, you can confirm the successful installation by checking the contents of the 'my_packages' directory.

export PYTHONPATH=/path/to/custom_directory:$PYTHONPATH
pip install requests --target ~/my_packages

Setting the PYTHONPATH Environment Variable

Another method to install packages into a custom directory is by modifying the PYTHONPATH environment variable. This approach enables Python to recognize packages located in the specified directory.

Syntax

Set the 'PYTHONPATH' variable. Install the desired package by using the following command.

export PYTHONPATH=/path/to/custom_directory:$PYTHONPATH
pip install package_name

Example

Here, 'export PYTHONPATH' adds '~/custom_lib' to the existing path, allowing Python to search that directory for packages. After installation, Python will search the default site-packages and your custom directory for the NumPy package.

export PYTHONPATH=~/custom_lib:$PYTHONPATH
pip install numpy

Using a Virtual Environment

Creating and using a virtual environment is one of the best practices in Python development. It allows you to create isolated environments for your projects, with distinct packages for each one.

Setting up a Virtual Environment

Create a virtual environment. Activate the virtual environment. Install your desired package.

python -m venv /path/to/custom_virtualenv
python -m venv /path/to/custom_virtualenv
source /path/to/custom_virtualenv/bin/activate
pip install package_name

Example

In the following examples, the command 'python -m venv ~/my_env' sets up a new virtual environment in the specified directory. Activating the environment using 'source ~/my_env/bin/activate' switches your terminal to use this environment.

After activation, running 'pip install flask' installs Flask exclusively within 'my_env', leaving your system-wide packages untouched.

python -m venv ~/my_env
source ~/my_env/bin/activate
pip install flask