raise an error python code example

Example 1: throwing an exception python

raise Exception("message")

Example 2: raise exception in python

raise Exception('I know Python!') # Don't! If you catch, likely to hide bugs.

Example 3: raise exception in python

#raise exception
raise ValueError('A very specific bad thing happened.')

Example 4: python exception

try:
  # code block
except ValueError as ve:
  print(ve)

Example 5: python raise error exit

# There are 3 approaches, the first as lvc mentioned is using sys.exit
sys.exit('My error message')

# The second way is using print, print can write almost anything including an error message
print >>sys.stderr, "fatal error"     # Python 2.x
print("fatal error", file=sys.stderr) # Python 3.x

# The third way is to rise an exception which I don't like because it can be try-catch
raise SystemExit('error in code want to exit')

# it can be ignored like this
try:
  raise SystemExit('error in code want to exit')
except:
  print("program is still open")

Example 6: python: raise error

class MyError(TypeError):
    pass

raise MyError('An error happened')