Kindly explain why should we use the raise statement.

Question

I clearly understood exception handling with try/except statement. But, not able understand what is meant by the raise statement. Please explain

Answer 1

Suppose you are writing an adventure text game, and a function to react to a direction order from user:

def go_dir(d):
if s.lower() in ('north','south','east','west'):
/* do the stuff */
else:
raise ValueError('Unknown direction')

... later in code you can call it and usually catch the exception if user set a bad value more easily ( and the verification code is factorized at value using place ):

try:
cmd = input('Command? ')
cmd = cmd.split(' ')
if cmd[0].lower() == 'go'
go_dir(cmd[1])
elif:
# do other commands treatments
except:
# do some error handling