switchcase
switchcase
implements a simple Switch-Case construct in Pure Python.
Under the hood, the switch
function works by simply returning a length-1
list containing a matching function. The entire implementation is 3 lines long:
from operator import eq
def switch(value, comp=eq):
return [lambda match: comp(match, value)]
Basic Usage
>>> from switchcase import switch
>>> def func(x):
... for case in switch(x):
... if case(0):
... print("x was 0")
... break
... if case(1):
... print("x was 1")
... break
... else:
... print("x was unmatched")
>>> func(0)
"x was 0"
>>> func(1)
"x was 1"
>>> func(2)
"x was unmatched"
Custom Comparisons
By default, switch
uses operator.eq
to compare the value passed to
switch
and the values subsequently passed to case
. You can override
this behavior by passing a comparator function to switch
as a second
argument.
>>> import re
>>> from switchcase import switch
>>> def f(x):
... out = []
... for case in switch(x, comp=re.match):
... if case("foo_bar"):
... out.append(0)
... break
... if case("foo_.*"):
... out.append(1)
... if case(".*_bar"):
... out.append(2)
... return out
>>> f("foo_bar")
[0]
>>> f("foo_notbar")
[1]
>>> f("notfoo_bar")
[2]
>>> f("foo____bar")
[1, 2]