how to get the key information from a KeyError

Question

Is there a way to get the key that raised a KeyError?

or in general, where can I find (if available) properties of an Exception?

Answer 1

Exceptions have a .args attribute which is a tuple; for a KeyError exception that tuple contains the key that triggered the exception:

>>> try:
...     {}['foo']
... except KeyError as ex:
...     print(ex.args[0])
... 
foo