switch case in python doesn't work; need another pattern

Question

I need a help with a code here, i wanted to implement the switch case pattern in python so like some tutorial said , i can use a dictionary for that but here is my problem:<

Answer 1

Since the code you want to execute in each case is from a safe source, you could store each snippet in a separate string expression in a dictionary and do something along these lines:

message = { 'create': '"blabla %s" % msg(some_data)',
            'update': '"blabla %s" % msg(other_data)',
            'delete': '"blabla %s" % diff(other_data, some_data)'
          }

return eval(message[type_])

The expression on the last line could also be eval(message.get(type_, '"unknown type_"')) to provide a default. Either way, to keep things readable the ugly details could be hidden:

switch = lambda type_: eval(message.get(type_, '"unknown type_"'))

return switch(type_)

The code snippets can even be precompiled for a little more speed:

from compiler import compile # deprecated since version 2.6: Removed in Python 3

for k in message:
    message[k] = compile(message[k], 'message case', 'eval')