Fixing Python aiohttp Error ‘Could Not Build Wheels’

Understanding the Error

The error ‘Could not build wheels‘ that appears when you’re working with Python and aiohttp is usually related to the installation process. It indicates that Python cannot compile the aiohttp package into a wheel, a built-package format. Common causes for this error include incompatible Python/pip versions, issues with system dependencies, or a lack of required build tools.

Solutions to the Error

Update pip and setuptools

Keeping pip, setuptools, and wheel up to date often solves errors related to the building or installation of packages:

1. Run pip install --upgrade pip setuptools wheel in your terminal.
2. Try reinstalling aiohttp.

Code Example:

python -m pip install --upgrade pip setuptools wheel
python -m pip install aiohttp

Advantages:

• Simple to execute.
• Addresses the most common cause.

Limitations: May not resolve system-specific dependency issues.

Install build dependencies

Some packages require specific build dependencies that need to be installed on the system. Below is the process to follow:

1. Install system-level packages. On Ubuntu, you would typically use apt:
2. sudo apt-get install build-essential install the essential compiling tools.
3. sudo apt-get install python3-dev install the Python development headers.
4. Reattempt the aiohttp installation.

Code Example:

sudo apt-get update
sudo apt-get install build-essential python3-dev
python -m pip install aiohttp

Advantages: Ensures all necessary build tools and headers are available.

Limitations: Dependent on the type of system (the example is specific to Debian-based systems like Ubuntu).

Use a Virtual Environment

Isolating your development environment can sidestep conflicts with system-wide packages. The steps to get the job done are shown below:

1. Create a virtual environment using python -m venv /path/to/new/virtual/environment.
2. Activate the virtual environment:
3. For Windows: \path\to\env\Scripts\activate
4. For Unix or MacOS: source /path/to/env/bin/activate
5. Install aiohttp within the virtual environment.

Code Example:

python -m venv myenv
cd myenv
source bin/activate  # For Unix/MacOS
cd Scripts & activate  # For Windows
pip install aiohttp

Advantages:

• Prevents package version conflicts.
• Makes your project portable and easier to deploy.

Limitations: Some learning curve for those new to virtual environments.