Python is a programming language that can be integrated with SPSS versions 14 and higher. By using Python in SPSS you can automate basically any SPSS task such as batch processing data files or output tables and charts.
Recent SPSS versions allow you to add SPSS extensions similarly to apps on a smartphone. Most extensions can be used from SPSS’ menu and use Python under the hood. So even if you're not planning to learn any Python, installing it may turn out very useful anyway.