This is an attempt at creating a way to do a reliable, not-bug-prone
implementation, for Python, of a switch
thing like other languages
have.
Suppose you have an enum, like this:
class Color(Enum):
RED = 1
GREEN = 2
BLUE = 3
And you want to implement logic which branches based on a value which is of type Color
.
You can do it by subclassing the Switch
class. The syntax should be obvious, but:
- Inherit from Switch
- Implement a method for each value of the Enum
- If you are not implementing them all: add a
default
method. - If you leave any Enum value unaccounted for: it will raise an exception when you instantiate your class.
Then:
- Instantiate your class
- Call it as a function passing it a value from the Enum
- The respective method will be executed and its return value returned
from enum_switch import Switch
class MySwitch(Switch):
def RED(self):
return "Apple"
def GREEN(self):
return "Kiwi"
def BLUE(self):
return "Sky"
switch = MySwitch(Color)
print(switch(Color.RED))
Apple
And that's it.
Some additional notes:
- Passing it something that is not a value of the correct Enum type will raise ValueError
default
is optional
Hope someone finds it useful!