The new case_when method in Pandas 2.2.0

Pandas 2.2.0 includes a new method, case_when. What is it, and how can you use it? I give an overview, with a number of examples.

Note: In my excitement to get this video done, I showed a different example than I had planned for passing a method; the call to str.contains returns a boolean series, and isn't actually a callable.

Here's a simple example of passing a callable, albeit not the most interesting one:

s.case_when(caselist=[(lambda s_: s_.lt(500), 'low'),
(lambda s_: …

call example examples overview pandas returns video