Switch-case replacement | Python Fiddle

"""
Pythonic switch/case implementation

Switch/case is faster than condition list because it is converted into a hash table
look up when compiled to machine code.
Python already offers easy and fast and flexible access to hash table usage that you
can use. Mind, however, principles of simplicity and readability so use this way of
implementation only in case of high number of choices.
"""

__author__ = "Bárdos Dávid"

unknown = "X"

# Step by step implementation
cases = {"A": "a",  # adding values
         "B": "b",
         "X": "x"}

def switch(expression):
    """lightning fast switch=>case implementation"""
    return cases[expression]

# usage
result = switch(unknown)
print(result)

# -------------------------------------------------------------------------------------

# The same in only 2 lines. Note that it is shorter than it would un switch/case syntax
cases_a = {"A": "aa", "B": "bb", "X": "xx"}
print(cases_a[unknown])

# -------------------------------------------------------------------------------------

# The same in only 2 lines with X as default value that is returned when no cases fits
cases_b = {"A": "aaa", "B": "bbb"}
print(cases_b.get(unknown, "xxx"))

# -------------------------------------------------------------------------------------

# The same with function calls, with default value
def a():
    print("aaaa")

def b():
    print("bbbb")

def x():
    print("xxxx")

cases_c = {"A": a, "B": b}
cases_c.get(unknown, x)()

# -------------------------------------------------------------------------------------

# Function calls without default value
cases_c = {"A": a, "B": b, "X": x}
cases_c[unknown]()

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