Python Can't Install New Packages from PyPI

John D K -

In this tutorial, we'll deep dive into several reasons why you can't install new packages from PyPI.

This post will describe the different kinds of errors and their solution in Python - tested in Linux and Windows.

Documentation about installing Python packages with Pip: pip install

Reason 1: Dependency Error - "Installing build dependencies ... error"

The first reason that prevents you from installing the latest package versions is dependency error.

In the example below we are trying to install black==20.8b1

pip install black

but the installation fails due to next error:

 pip install black==20.8b1
Collecting black==20.8b1
  Using cached black-20.8b1.tar.gz (1.1 MB)
  Installing build dependencies ... error

A possible solution is to check the latest versions of the package and to install one which is:

  • supported by your version
  • doesn't have dependency issues
pip install black==19.10b0

Reason 2: Upgrade pip/setuptools before installation of new packages

In case of errors or getting the wrong package version you can try to upgrade your package manager.

In case of a pip:

python -m pip install --upgrade pip

Latest package versions might require features which are present in the latest versions of pip, conda etc.

Some package require also package setuptools which can be upgraded by:

pip install setuptools --upgrade

or

pip install -U setuptools

Reason 3: Package is not supported by Python version

When a new Python version is released (i.e. 3.8, 3.9 etc) the package needs updates in order to support it.

You will face errors like:

running dist_info
        running build_src
        build_src
        building py_modules sources
        creating build
        creating build\src.win-amd64-3.9
        creating build\src.win-amd64-3.9\numpy
        creating build\src.win-amd64-3.9\numpy\distutils
        building library "npymath" sources
        error: Microsoft Visual C++ 14.0 is required. Get it with "Build Tools for Visual Studio": https://visualstudio.microsoft.com/downloads/

or

error: Microsoft Visual C++ 14.0 is required (Unable to find vcvarsall.bat)

or

ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

If you install a brand new version there is a high probability that many packages will fail to be installed.

There are two things you can do in this case:

  1. Verify the latest stable and secure Python version from:

You can find - end-of-life, security and bugfix. Take the latest security one.

  1. Check if the problematic package support your Python version:

Bonus for Windows: Windows Pip version - pipwin

Pipwin is advertised as:

pipwin is a complementary tool for pip on Windows. pipwin installs unofficial python package binaries for windows

It can help if you use Windows and Python:

pip install pipwin
pipwin install black