Installing specific package versions with pip

Question

I am trying to install version 1.2.2 of MySQL_python, using a fresh virtualenv created with the --no-site-packages option. The current version shown in PyPi is 1.2.3. Is there a way to install the older version? I have tried:

pip install MySQL_python==1.2.2 

However, when installed, it still shows MySQL_python-1.2.3-py2.6.egg-info in the site packages. Is this a problem specific to this package, or am I doing something wrong?

Answer 1

TL;DR:

• pip install -Iv (i.e. pip install -Iv MySQL_python==1.2.2)

What these options mean:

• -I stands for --ignore-installed which will ignore the installed packages, overwriting them.
• -v is for verbose. You can combine for even more verbosity (i.e. -vv) up to 3 times (e.g. -Ivvv).

For more information, see pip install --help

First, I see two issues with what you're trying to do. Since you already have an installed version, you should either uninstall the current existing driver or use pip install -I MySQL_python==1.2.2

However, you'll soon find out that this doesn't work. If you look at pip's installation log, or if you do a pip install -Iv MySQL_python==1.2.2 you'll find that the PyPI URL link does not work for MySQL_python v1.2.2. You can verify this here: http://pypi.python.org/pypi/MySQL-python/1.2.2

The download link 404s and the fallback URL links are re-directing infinitely due to sourceforge.net's recent upgrade and PyPI's stale URL.

So to properly install the driver, you can follow these steps:

pip uninstall MySQL_python pip install -Iv http://sourceforge.net/projects/mysql-python/files/mysql-python/1.2.2/MySQL-python-1.2.2.tar.gz/download 

Answer 2

You can even use a version range with pip install command. Something like this:

pip install 'stevedore>=1.3.0,<1.4.0' 

And if the package is already installed and you want to downgrade it add --force-reinstall like this:

pip install 'stevedore>=1.3.0,<1.4.0' --force-reinstall