There are different ways to use Python in SPSS. The easiest is to just copy-paste-run the syntax you need. However, most users will at some point want to write their own Python syntax. Even more efficiency can be gained by passing code into functions and eventually modules. This tutorial walks you through the options from most basic to most advanced.
1. Copy Paste Run
2. Write Your Own Syntax
3. Write Your Own Functions
4. Write Your Own ModuleA Useful SPSS Python Module can be as Short as Five Lines of Code
This is where it gets really interesting. A module is a simple text file containing functions and/or other statements. By moving functions into a module, you don't need their code in your SPSS syntax files anymore. After importing your module, you can use each of its functions with a single line of code. This will render your SPSS syntax much shorter and more readable. Another advantage is that if you discover some mistake in one of your functions, you need to correct it just once (in your module). All syntax files that use this function will now use the corrected version and there's no need to correct each of them individually.
5. Create Custom Dialogs and Toolbar Tools
SPSS Syntax - including SPSS Python syntax - can be Pasted and/or run from the GUI (Graphical User Interface, the 'point-click menu'). There are two basic ways to do this.
- Attach a toolbar item to a syntax file. Also, see SPSS Toolbar Tool Building. You can now run your syntax with a single left mouse click. However, this syntax won't be pasted in your syntax window and you can't pass any parameters into it.
- Create an SPSS custom dialog. In this case, you'll need more than a single mouse click to run this syntax but you can pass one or more parameters (such as variables) into it and paste the result.
Three Reasons for Creating your Own Menu Items
- Accessibility. If you're working with a client, he may be not entirely comfortable with SPSS (Python) syntax. However, most users are at ease with using menu items regardless of what code is lying underneath them.
- Ease. If you want to run a function from your own module, the function call should be exactly correct. That is, you must the exact function name (including the capitalization - if any) and the way parameters should be specified. By having a dialog window generate the function call for you, you don't need to memorize any of that.
- Speed. A single mouse click is probably the fastest possible way to run syntax.