how to program an error python code example

Example 1: python raise exception

# this raises a "NameError"

>>> raise NameError('HiThere')

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: HiThere

Example 2: try except python

def sum_of(x, y):
  try:
    print(x + y)
  except TypeError:
    print("Invalid argument specified.")