Since Python doesn't have a switch statement, what should I use?
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Replacements for switch statement in python?
I'm making a little console based application in Python and I wanted to use a Switch statement to handle the users choice of a menu selection.
What do you vets suggest I use. Thanks!
Dispatch tables, or rather dictionaries.
You map keys aka. values of the menu selection to functions performing said choices:
def AddRecordHandler():
print("added")
def DeleteRecordHandler():
print("deleted")
def CreateDatabaseHandler():
print("done")
def FlushToDiskHandler():
print("i feel flushed")
def SearchHandler():
print("not found")
def CleanupAndQuit():
print("byez")
menuchoices = {'a':AddRecordHandler, 'd':DeleteRecordHandler, 'c':CreateDatabaseHandler, 'f':FlushToDiskHandler, 's':SearchHandler, 'q':CleanupAndQuit}
ret = menuchoices[input()]()
if ret is None:
print("Something went wrong! Call the police!")
menuchoices['q']()
Remember to validate your input! :)
There are two choices, first is the standard if ... elif ... chain. The other is a dictionary mapping selections to callables (of functions are a subset). Depends on exactly what you're doing which one is the better idea.
elif chain
selection = get_input()
if selection == 'option1':
handle_option1()
elif selection == 'option2':
handle_option2()
elif selection == 'option3':
some = code + that
[does(something) for something in range(0, 3)]
else:
I_dont_understand_you()
dictionary:
# Somewhere in your program setup...
def handle_option3():
some = code + that
[does(something) for something in range(0, 3)]
seldict = {
'option1': handle_option1,
'option2': handle_option2,
'option3': handle_option3
}
# later on
selection = get_input()
callable = seldict.get(selection)
if callable is None:
I_dont_understand_you()
else:
callable()
Use a dictionary to map input to functions.
switchdict = { "inputA":AHandler, "inputB":BHandler}
Where the handlers can be any callable. Then you use it like this:
switchdict[input]()