How to work within individual files rather than projects in PyCharm

On Pycharm 5.0.4…

1. Open the file (i.e. by double clicking in explorer)
2. Navigate to File->Settings…
3. Expand the Project tab on the left and select ‘project interpreter’ from the options that appear beneath
4. Set your project interpreter from the dropdown menu, and you should be able now to run your file without creating a project