Determining what version of Flask is installed

It's quite simple !

In your terminal:

pip freeze | grep Flask

The output should be something like this:

Output: Flask==0.12

Via the python interpreter.

>> import flask
>> flask.__version__
'0.7.2'

If flask was installed via pip or easy_install, you can always use the 'pip freeze' command.

More general way of doing it is :

pip freeze

It will list all installed python packages and their versions. If you want to see just flask then try :

pip freeze | grep flask

As of flask 0.7 (June 28th, 2011), a __version__ attribute can be found on the flask module.

>> import flask
>> flask.__version__

Keep in mind that because prior to flask 0.7 there was no __version__ attribute, the preceding code will result in an attribute error on those older versions.

For versions older than flask 0.7, you might be able to determine it using pkg_resources as shown below:

>>> import pkg_resources
>>> pkg_resources.get_distribution('flask').version
'0.6.1'

This won't work 100% though. It depends on the user having the pkg_resources library installed (it might come by default with a Linux distribution's python installation, but since it's not part of the standard library you can't be positive), and also that the user installed flask in a way that pkg_resources can find it (for example, just copying the full flask source code into your directory puts it out of the range of pkg_resources).