Python Language groupby()


In Python, the itertools.groupby() method allows developers to group values of an iterable class based on a specified property into another iterable set of values.


  • itertools.groupby(iterable, key=None or some function)


iterableAny python iterable
keyFunction(criteria) on which to group the iterable


groupby() is tricky but a general rule to keep in mind when using it is this:

Always sort the items you want to group with the same key you want to use for grouping

It is recommended that the reader take a look at the documentation here and see how it is explained using a class definition.