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?
pip install -Iv(i.e.
pip install -Iv MySQL_python==1.2.2)
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 install -Iv MySQL_python==1.2.2
== and mention the version number to install only that version.
-I, --ignore-installed ignores already installed packages.
To install a specific python package version whether it is the first time, an upgrade or a downgrade use:
pip install --force-reinstall MySQL_python==1.2.4
MySQL_python version 1.2.2 is not available so I used a different version. To view all available package versions from an index exclude the version:
pip install MySQL_python==
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.
Sometimes, the previously installed version is cached.
~$ pip install pillow==5.2.0
It returns the followings:
Requirement already satisfied: pillow==5.2.0 in /home/ubuntu/anaconda3/lib/python3.6/site-packages (5.2.0)
We can use –no-cache-dir together with -I to overwrite this
~$ pip install --no-cache-dir -I pillow==5.2.0
Since this appeared to be a breaking change introduced in version 10 of pip, I downgraded to a compatible version:
pip install 'pip<10'
This command tells pip to install a version of the module lower than version 10. Do this in a virutalenv so you don’t screw up your site installation of Python.
This below command worked for me
Python version – 2.7
package – python-jenkins
$ pip install 'python-jenkins>=1.1.1'
I recently ran into an issue when using
-I flag that I wanted to document somewhere:
-I will not uninstall the existing package before proceeding; it will just install it on top of the old one. This means that any files that should be deleted between versions will instead be left in place. This can cause weird behavior if those files share names with other installed modules.
For example, let’s say there’s a package named
package. In one of
packages files, they use
import datetime. Now, in
[email protected], this points to the standard library
datetime module, but in
[email protected], they added a local
datetime.py as a replacement for the standard library version (for whatever reason).
Now lets say I run
pip install package==3.0.0, but then later realize that I actually wanted version
2.0.0. If I now run
pip install -I package==2.0.0, the old
datetime.py file will not be removed, so any calls to
import datetime will import the wrong module.
In my case, this manifested with strange syntax errors because the newer version of the package added a file that was only compatible with Python 3, and when I downgraded package versions to support Python 2, I continued importing the Python-3-only module.
Based on this, I would argue that uninstalling the old package is always preferable to using
-I when updating installed package versions.
There are 2 ways you may install any package with version:-
A). pip install -Iv package-name == version
B). pip install -v package-name == version
Here, if you’re using -I option while installing(when you don’t know if the package is already installed) (like ‘pip install -Iv pyreadline == 2.* ‘or something), you would be installing a new separate package with the same existing package having some different version.
- At first, you may want to check for no broken requirements.
2.and then see what’s already installed by
3.if the list of the packages contain any package that you wish to install with specific version then the better option is to uninstall the package of this version first, by
pip uninstall package-name
4.And now you can go ahead to reinstall the same package with a specific version, by
pip install -v package-name==version
e.g. pip install -v pyreadline == 2.*
If you want to update to latest version and you don’t know what is the latest version you can type.
pip install MySQL_python –upgrade
This will update the MySQL_python for latest version available, you can use for any other package version.