[Tut] Fix Installation Error of ‘unittest’

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Fix Installation Error of ‘unittest’

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The

Code:

unittest

module is part of Python’s standard library for a long time. So in most cases, there’s no need to install it using something like

Code:

pip install unittest

. Simply run

Code:

import unittest

in your Python code and it works without installation.

In your Python code:

Code:

import unittest

If you try to

Code:

pip install

it, you’ll get the following error

Code:

Could not find a version that satisfies the requirement unittest

that you can fix by not installing it in the first place (it already is)!

Code:

PS C:\Users\xcent> pip install unittest ERROR: Could not find a version that satisfies the requirement unittest (from versions: none) ERROR: No matching distribution found for unittest

Recommended Tutorial: How to Check ‘

Code:

unittest

‘ Package Version in Python?

Feel free to also check out our full guide on the PyTest framework which is great for testing purposes too!

Python 2 Backport UnitTest2

If you’re using Python 2, you can try installing the

Code:

unittest2

package that is a backport for unit testing in Python 2.7. Then

Code:

pip install unittest2

Then add the following line to your Python code instead of

Code:

import unittest

:

Code:

import unittest2

Legacy Solutions to Install UnitTest Module

For some very old Python versions, you may want to try this approach:

Quick Fix: Python raises the

Code:

ImportError: No module named 'unittest'

when it cannot find the library

Code:

unittest

. The most frequent source of this error is that you haven’t installed

Code:

unittest

explicitly with

Code:

pip install unittest

. Alternatively, you may have different Python versions on your computer, and

Code:

unittest

is not installed for the particular version you’re using.

To fix this error, you can run the following command in your Windows shell:

Code:

$ pip install unittest

This simple command installs

Code:

unittest

in your virtual environment on Windows, Linux, and MacOS. It assumes that your

Code:

pip

version is updated. If it isn’t, use the following two commands in your terminal, command line, or shell (there’s no harm in doing it anyways):

Code:

$ python -m pip install – upgrade pip $ pip install pandas

Note: Don’t copy and paste the

Code:

$

symbol. This is just to illustrate that you run it in your shell/terminal/command line.

The error might persist even after you have installed the

Code:

unittest

library. This likely happens because

Code:

pip

is installed but doesn’t reside in the path you can use. Although

Code:

pip

may be installed on your system the script is unable to locate it. Therefore, it is unable to install the library using

Code:

pip

in the correct path.

To fix the problem with the path in Windows follow the steps given next.

Step 1: Open the folder where you installed Python by opening the command prompt and typing

Code:

where python

Step 2: Once you have opened the

Code:

Python

folder, browse and open the

Code:

Scripts

folder and copy its location. Also verify that the folder contains the

Code:

pip

file.



Step 3: Now open the

Code:

Scripts

directory in the command prompt using the

Code:

cd

command and the location that you copied previously.



Step 4: Now install the library using

Code:

pip install unittest

command. Here’s an analogous example:



After having followed the above steps, execute our script once again. And you should get the desired output.

Other Solution Ideas

• The
  Code:

  ModuleNotFoundError
  may appear due to relative imports. You can learn everything about relative imports and how to create your own module in this article.
  
  
• You may have mixed up Python and pip versions on your machine. In this case, to install
  Code:

  unittest
  for Python 3, you may want to try
  Code:

  python3 -m pip install unittest
  or even
  Code:

  pip3 install unittest
  instead of
  Code:

  pip install unittest
  
  
• If you face this issue server-side, you may want to try the command
  Code:

  pip install – user unittest
  
  
• If you’re using Ubuntu, you may want to try this command:
  Code:

  sudo apt install unittest
  
  
• You can check out our in-depth guide on installing
  Code:

  unittest
  here.
  
  
• You can also check out this article to learn more about possible problems that may lead to an error when importing a library.
  

Understanding the “import” Statement

Code:

import unittest

In Python, the

Code:

import

statement serves two main purposes:

• Search the module by its name, load it, and initialize it.
  
  
• Define a name in the local namespace within the scope of the
  Code:

  import
  statement. This local name is then used to reference the accessed module throughout the code.
  

What’s the Difference Between ImportError and ModuleNotFoundError?

What’s the difference between

Code:

ImportError

and

Code:

ModuleNotFoundError

?

Python defines an error hierarchy, so some error classes inherit from other error classes. In our case, the

Code:

ModuleNotFoundError

is a subclass of the

Code:

ImportError

class.

You can see this in this screenshot from the docs:



You can also check this relationship using the

Code:

issubclass()

built-in function:

Code:

>>> issubclass(ModuleNotFoundError, ImportError) True

Specifically, Python raises the

Code:

ModuleNotFoundError

if the module (e.g.,

Code:

unittest

) cannot be found. If it can be found, there may be a problem loading the module or some specific files within the module. In those cases, Python would raise an

Code:

ImportError

.

If an import statement cannot import a module, it raises an

Code:

ImportError

. This may occur because of a faulty installation or an invalid path. In Python 3.6 or newer, this will usually raise a

Code:

ModuleNotFoundError

.

Related Videos

The following video shows you how to resolve the

Code:

ImportError

:



The following video shows you how to import a function from another folder—doing it the wrong way often results in the

Code:

ModuleNotFoundError

:



Here’s a full guide on how to install a library on PyCharm.

• How to Install a Library on PyCharm