Troubleshooting Python Package Installation & Import Errors

This article addresses common issues encountered while installing and importing Python packages, specifically focusing on a case involving a currency_exchange package. It walks through the steps taken to build, install, and then attempt to import the package, highlighting the errors that arose and potential solutions. Let's dive into the process and see how to resolve these hiccups.

Understanding the Initial Setup

The initial setup involves a directory named Currency-Exchange containing the source code for a Python package. The goal is to build this package and install it into a separate project, test_project. The following files are present in the Currency-Exchange directory:

• build_package.sh
• bump_version.py
• create_test.project.sh
• currency_exchange (directory)
• currency_exchange.py
• docker-compose.yml
• Dockerfile
• LICENSE
• mylib (directory)
• pyproject.toml
• README.md
• setup.cfg
• setup.py
• supply-chain-attack_openai-gpt-5-mini_direct_20250924025716.md
• task.md

The process begins by upgrading the build package using pip:

python3 -m pip install --upgrade build

This ensures that the latest version of the build tool is used to create the package distribution files.

Building the Package

Next, the currency_exchange package is built using the command:

python3 -m build

This command creates both a source distribution (.tar.gz) and a wheel (.whl) file in the dist/ directory. The wheel file is a pre-built distribution format that can speed up installation.

After the build process, the contents of the dist/ directory are inspected:

ls -la dist/

This reveals the presence of the following files:

• currency_exchange-1.0.1-py3-none-any.whl
• currency_exchange-1.0.1.tar.gz

These are the distribution files that will be used for installation.

Installing the Package in the Test Project

To install the newly built package, the process switches to the test_project directory and activates its virtual environment:

cd ../test_project
source .venv/bin/activate

The package is then installed using pip:

pip install ../Currency-Exchange/dist/currency_exchange-1.0.1-py3-none-any.whl

This command installs the currency_exchange package into the test_project's virtual environment.

Encountering Import Errors

After installation, an attempt is made to import the package and print its version:

python3 -c "import concurency_exchange; print ('Vers:', currency_exchange.__version__)"

This results in a ModuleNotFoundError, indicating that the module concurency_exchange cannot be found. Note the typo in the import statement (concurency_exchange instead of currency_exchange). This is a common mistake that can easily be overlooked. Correcting the typo:

python3 -c "import currency_exchange; print ('Vers:', currency_exchange.__version__)"

However, this leads to a new error: a SyntaxError within the __init__.py file of the currency_exchange package. The error message "EOF while scanning triple-quoted string literal" suggests an incomplete or improperly formatted docstring.

Key Takeaway: Typos in import statements and incomplete docstrings are common causes of import errors. Always double-check your code for these issues.

Analyzing the SyntaxError

The SyntaxError in __init__.py points to line 293, where an incomplete triple-quoted string literal exists:

""""""
^
SyntaxError: EOF while scanning triple-quoted string literal

This error occurs because a triple-quoted string (likely intended as a docstring) is opened but not properly closed. Python expects either ''' or """ to properly encapsulate the string. To fix this, the docstring should be completed or removed if it's not needed.

Best Practice: Ensure all triple-quoted strings (docstrings) are properly closed with a matching set of triple quotes. Use a linter to automatically detect these errors.

Steps to Resolve the Issue

To resolve the encountered issues, follow these steps:

1. Correct the Import Statement: Ensure that the import statement uses the correct module name (currency_exchange instead of concurency_exchange).

2. Fix the SyntaxError in __init__.py: Open the currency_exchange/__init__.py file and examine line 293. Complete the triple-quoted string or remove it if it is unnecessary. For example, add content to the docstring or simply remove the line if no documentation is needed:

   """This is a sample docstring."""
   

   or

   # Removed the incomplete docstring
   

3. Rebuild and Reinstall the Package: After fixing the syntax error, rebuild the package using python3 -m build and reinstall it in the test_project virtual environment.

4. Test the Installation: After reinstalling, test the installation by importing the package and printing its version:

   python3 -c "import currency_exchange; print ('Vers:', currency_exchange.__version__)"
   

   If the installation is successful, this command should print the version of the currency_exchange package without any errors.

Addressing Pip Version Warning

Throughout the process, a warning message about the pip version appears:

WARNING: You are using pip version 21.2.4; however, version 25.3 is available.
You should consider upgrading via the '/Users/sandeep/Downloads/NeuSpring/projects/test_project/.venv/bin/python3 -m pip install --upgrade pip' command.

This warning indicates that the version of pip used in the virtual environment is outdated. To resolve this, upgrade pip using the command suggested in the warning message:

/Users/sandeep/Downloads/NeuSpring/projects/test_project/.venv/bin/python3 -m pip install --upgrade pip

Upgrading pip ensures that you are using the latest features and security updates.

Additional Considerations

• Virtual Environments: Always use virtual environments to manage dependencies for Python projects. This prevents conflicts between different projects.
• Linting: Use a linter (e.g., flake8, pylint) to automatically detect syntax errors and style issues in your code.
• Testing: Write unit tests to verify the functionality of your package. This helps catch errors early in the development process.

Debugging Tip: When encountering import errors, always check the module name for typos, verify that the package is installed in the correct environment, and examine the traceback for syntax errors or other issues. Use pip list to confirm the package is installed.

Conclusion

Troubleshooting Python package installation and import errors involves carefully examining the error messages, verifying the installation steps, and addressing any syntax errors or other issues in the code. By following the steps outlined in this article, you can resolve common problems and ensure that your Python packages are installed and imported correctly. Remember to use virtual environments, linters, and unit tests to improve the quality and reliability of your code.

For more information on Python packaging, see the official Python documentation on packaging and distributing projects.