CODEWITHSUNDEEP
pythonswitch-statement
Sandt50
Sandt50

Reputation: 19

Most elegant way for a switch case as in C

In order to parse some args via cmd line, I've a "switch case" written with if .. elif

if arg == 1:
    ..something...
elif arg >= 2 and arg < 4:
    ..something else ...
elif arg < 6:
    ..something else ...
else:
    ..something else ...

above, elif arg < 6: could be replaced by: elif arg == 4 or arg == 5:

this get's a bit messy when there are more argument values to check.

What could be the most efficient and easy way to read the code?

Upvotes: 1

Views: 180

Answers (2)

Fred Mitchell
Fred Mitchell

Reputation: 2161

If your goal really is to parse a command line, use optparse if in python 2.6 or lower, argparse for later python versions. There is also a really nice little package called aaargh that makes for some really concise code. You will need to use decorators with that, so probably save that for a later project.

Use optparse or argparse, you can use things like -d somedir or --dir=somedir. It allows you to handle both optional parameters in any order, as well as required ones.

It also will generate a help message, if the command line does not meet your requirements.

Upvotes: 0

David K. Hess
David K. Hess

Reputation: 17246

You could try something like this:

def case_A():
    .. something ..

def case_B():
    .. something ..

def case_C():
    .. something ..

def case_else():
    .. something ..

{
    1: case_A,
    2: case_B,
    3: case_B,
    4: case_C,
    5: case_C
}.get(arg, case_else)()

Upvotes: 2

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