CODEWITHSUNDEEP
pythoncoding-styleswitch-statementconditional-statements
chemiker
chemiker

Reputation: 1

Coding-style for conditional operator in python

I want to get devs' opinions about next code examples. Which code is more readable? Which is better style?

Note: expression int(a is not None) + 3*int(b is not None) + 5*int(a != b) return unique code for all combinations values of listed conditions.

And sorry for my english. I am trying to make it better.

First:

if (a is not None) and (b is not None) and (a != b):
   exit()
elif (a is not None) and (b is not None) and (a = b):
   func1()
elif (a is not None) and (b is None):
   func2()
elif (a is None) and (b is not None):
   func3()
elif (a is None) and (b is None):
   func4

second:

code = int(a is not None) + 3*int(b is not None) + 5*int(a != b)
if code == 9:
   exit()
elif code == 4:
   func1()
elif code == 1:
   func2()
elif code == 3:
   func3()
elif code == 0:
   func4()

third:

code = int(a is not None) + 3*int(b is not None) + 5*int(a != b)    
switch = {9:exit, 4:func1, 1:func2, 3:func3, 0:func4}
switch[code]()

Upvotes: -1

Views: 53

Answers (1)

metaperture
metaperture

Reputation: 2463

I would do:

if a is None:
    if b is None: func4()
    else: func3()
else:
    if b is None: func2()
    elif a == b: func1()
    else: exit()

I'm definitely not a fan of the int switching. And, even more ideally, your structure for a and b would allow you to just check not a instead of a is None, which would be even cleaner.

In the off-chance that you do ever need to encode boolean flags into a number, I would also recommend that you use base 2 (1,2,4...) instead of the base system you're using (1,3,5..)--which might make sense if you were bounded by space (saving compressed data, eg Chess bitboards, or lots of fast network IO), but if you don't have a crazy requirement, remember:

"Premature optimization is the root of all evil." Donald Knuth

Upvotes: 4

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