Skip to main content

How to Solve "ModuleNotFoundError: No module named 'scipy'" in Python

The ModuleNotFoundError: No module named 'scipy' error means that Python can't find the scipy library. This usually happens because SciPy isn't installed, is installed in the wrong environment, or your IDE/Jupyter isn't configured correctly.

This guide will show you how to install SciPy and troubleshoot common installation problems.

Installing SciPy (The Basic Solution)​

The standard way to install SciPy is using pip:

pip install scipy

  • Multiple Python Versions: If you have multiple Python versions, you may need pip3 (or a more specific version):

    pip3 install scipy

  • Permissions Errors: If you get a permissions error, try:

    sudo pip3 install scipy  # Linux/macOS (Use with caution!)
    pip install scipy --user # Installs for the current user

    Using virtual environments (explained below) is the best way to avoid permission issues.

  • python -m pip: If pip isn't directly accessible, use this:

    python -m pip install scipy  # Or python3 -m pip

    This ensures you are using the pip that corresponds to your Python interpreter.

  • Anaconda: If you're using Anaconda, it's generally best to use conda:

    conda install -c anaconda scipy

Verifying the Installation​

After installing, verify the installation with a simple Python script:

from scipy import stats
from scipy.stats import norm

print(dir(stats)) # Prints a list of names defined in the module.

print('bounds of distribution lower: %s, upper: %s' % norm.support())
# Output: bounds of distribution lower: -inf, upper: inf

If this code runs without a ModuleNotFoundError, SciPy is installed and available. If you still get the error, proceed to the troubleshooting section.

Troubleshooting ModuleNotFoundError​

Virtual Environments (Essential)​

Always use virtual environments for your Python projects. This isolates project dependencies, prevents conflicts, and is crucial for reproducibility.

  1. Create a virtual environment (if you haven't already):

    python3 -m venv venv  # Or python -m venv venv , py -m venv venv

  2. Activate the environment:

    • Linux/macOS: source venv/bin/activate
    • Windows (cmd.exe): venv\Scripts\activate.bat
    • Windows (PowerShell): venv\Scripts\Activate.ps1
      • You might get error when running venv\Scripts\Activate.ps1. In this case run the command Set-ExecutionPolicy RemoteSigned -Scope CurrentUser in powershell and try again.

  3. Install SciPy inside the activated environment:

    pip install scipy

Your terminal prompt should now show the active environment (e.g., (venv) $). Now try running your script.

Multiple Python Versions​

Make sure you installed SciPy for the correct Python version.

  • Check your Python version: python --version (or python3 --version)
  • Use the correct pip: Use the pip (or pip3, pip3.x, or python -m pip) that corresponds to the Python version you are using.

IDE Configuration (VS Code, PyCharm)​

Your IDE (VS Code, PyCharm, etc.) needs to be configured to use the correct Python interpreter (and the correct virtual environment).

  • VS Code:

    1. Open the Command Palette (Ctrl+Shift+P or Cmd+Shift+P).
    2. Type "Python: Select Interpreter".
    3. Choose the interpreter associated with your virtual environment.

  • PyCharm:

    1. Go to "File" -> "Settings" -> "Project" -> "Python Interpreter".
    2. Select the correct interpreter from the dropdown (or add it if it's not listed).

Jupyter Notebook​

In a Jupyter Notebook cell, install with:

!pip install scipy
  • The ! is used to execute a terminal command within a notebook cell.
note

This installs SciPy into the environment Jupyter itself is running in. Make sure your Jupyter kernel is using the same environment as your project.

Naming Conflicts​

Never name your own files or directories scipy.py or scipy. Python might try to import your file/directory instead of the installed SciPy library. Rename your file/directory.

Reinstalling SciPy​

As a last resort, try uninstalling and reinstalling:

pip uninstall scipy
pip install scipy

Installation Instructions for Specific Environments​

Windows:​

  • Open Command Prompt or PowerShell.
  • Use pip install scipy (or py -m pip install scipy).

macOS / Linux:​

  • Open your Terminal
  • Use pip3 install scipy

Anaconda:​

  • Use conda install -c anaconda scipy

Jupyter Notebook (within a cell):​

!pip install scipy

Import Errors After Successful Installation​

Even if pip install scipy succeeds, you might still get import errors within your code if you aren't importing SciPy correctly. The following import statements are valid:

  • import scipy: imports the top-level SciPy package. You'll need to use scipy.submodule.function to access functions.
  • from scipy import submodule: imports a specific submodule (e.g., from scipy import stats). You can then use stats.function.
  • from scipy.submodule import function: imports a specific function (e.g., from scipy.stats import norm). You can then use function directly.

The code example below imports stats from scipy and uses the cdf method for cumulative distribution:

from scipy import stats
from scipy.stats import norm
print(stats.norm.cdf(0)) # Output: 0.5

Conclusion​

The ModuleNotFoundError: No module named 'scipy' error almost always indicates an installation or environment issue. The key is to:

  1. Use virtual environments.
  2. Install SciPy using the correct pip for your Python version.
  3. Ensure your IDE or Jupyter kernel is using the correct environment.
  4. Avoid naming conflicts.

By following these steps, you should be able to resolve the error and use SciPy successfully.

Table of Contents