I have PyCharm 1.5.4 and have used the "Open Directory" option to open the contents of a folder in the IDE.
I have Python version 3.2 selected (it shows up under the "External Libraries" node).
How can I select another version of Python (that I already have installed on my machine) so that PyCharm uses that version instead?
File -> Settings
Preferences->Project Interpreter->Python Interpreters
If it's not listed add it.
I think you are saying that you have python2 and python3 installed and have added a reference to each version under Pycharm > Settings > Project Interpreter
What I think you are asking is how do you have some projects run with Python 2 and some projects running with Python 3.
If so, you can look under Run > Edit Configurations