How to change the message in a Python AssertionError?

Question

I\'m writing per the following, in which I try to produce a decent error message when comparing two multiline blocks of Unicode text. The interior method that does the compa

Answer 1

Use e.args, e.message is deprecated.

try:
    assert False, "Hello!"
except AssertionError as e:
    e.args += ('some other', 'important', 'information', 42)
    raise

This preserves the original traceback. Its last part then looks like this:

AssertionError: ('Hello!', 'some other', 'important', 'information', 42)

Works in both Python 2.7 and Python 3.