Installing specific package version with pip

TL;DR:

Update as of 2022-12-28:

pip install --force-reinstall -v

For example: pip install --force-reinstall -v "MySQL_python==1.2.2"

What these options mean:

• --force-reinstall is an option to reinstall all packages even if they are already up-to-date.
• -v is for verbose. You can combine for even more verbosity (i.e. -vv) up to 3 times (e.g. --force-reinstall -vvv).

Thanks to @Peter for highlighting this (and it seems that the context of the question has broadened given the time when the question was first asked!), the documentation for Python discusses a caveat with using -I, in that it can break your installation if it was installed with a different package manager or if if your package is/was a different version.

Original answer:

• 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

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

One way, as suggested in this post, is to mention version in pip as:

pip install -Iv MySQL_python==1.2.2

i.e. Use == and mention the version number to install only that version. -I, --ignore-installed ignores already installed packages.

I believe that if you already have a package it installed, pip will not overwrite it with another version. Use -I to ignore previous versions.