5 ms·

Python doesn't have pattern matching but the code is basically the same. I guess better cases for showing off the feature are ones where the patterns aren't jus

Python doesn't have pattern matching but the code is basically the same. I guess better cases for showing off the feature are ones where the patterns aren't just True/False tuples. for i in range (1, 101): fbsign = (i % 3 == 0, i % 5 == 0) if fbsign == (1, 1): print("Fizzbuzz") elif fbsign == (1, 0): print("Fizz") elif fbsign == (0, 1): print("Buzz") else: print(i)

steveklabnik 12y ago
One difference is that this won't do exhaustiveness checks, where the pattern match will.
- Erwin 12y ago
  Well, here's an exhaustively checking version. Not statically still of course. for x in range(1,101): print [ # %3 = 0 [ x, "Fizz" ], [ "Buzz", "FizzBuzz"] # %5 = 0 ][x%3 == 0][x%5 == 0] (I'll note this was hard to get than if-checks and pattern matching so I won't be replacing such logic with matrices in my Python program any time soon...)
  - steveklabnik 12y ago
    > not statically of course Right, but that's the point!
mapleoin 12y ago
That is very non-idiomatic python. Use True and False instead of 1 and 0 when comparing the (boolean) result of a comparison.
Wilduck 12y ago
Some people are sayint this is extremely non idiomatic python. I think most of the problem is not following the style guides. Here's a pep8 compliant solution that is a bit more idomatic, and almost as compact. In Python, the way to do pattern matching is with dictionaries of functions. fizz_buzz = {(True, True): lambda x: "Fizzbuzz", (True, False): lambda x: "Fizz", (False, True): lambda x: "Buzz", (False, False): lambda x: x} for i in range(1, 30): fbsign = (i % 3 == 0, i % 5 == 0) print(fizz_buzz[fbsign](i))
- tel 12y ago
  That's not genuinely pattern matching, however. It only works for patterns without member binding.
  - deleted 12y ago
    [deleted]
- bluecalm 12y ago
  I see it as over thinking simple stuff. Maybe I think about performance too much but constructing a dictionary and then defining functions to do simple signature thing is imo just over designing things. Too much abstraction for expressing a simple concept. Performance aside, you need to go find the dictionary once you see code like that while with chain of if-else statements it's right there in front of your eyes. As to 0 and 1 thing... Python has C'ish boolean (basically an integer type). Using True and False as numbers is completely standard as PEP 285 indicates. I tend to agree that maybe here using True/False is a bit more natural but it really is type-purity nitpick in my view. Could you point out which part of PEP8 the code in my original post violates? While I don't really like a lot of currently popular style I see a lot of values in following the PEP's and long established conventions.

steveklabnik 12y ago

One difference is that this won't do exhaustiveness checks, where the pattern match will.

Erwin 12y ago
Well, here's an exhaustively checking version. Not statically still of course. for x in range(1,101): print [ # %3 = 0 [ x, "Fizz" ], [ "Buzz", "FizzBuzz"] # %5 = 0 ][x%3 == 0][x%5 == 0] (I'll note this was hard to get than if-checks and pattern matching so I won't be replacing such logic with matrices in my Python program any time soon...)
- steveklabnik 12y ago
  > not statically of course Right, but that's the point!

mapleoin 12y ago

That is very non-idiomatic python. Use True and False instead of 1 and 0 when comparing the (boolean) result of a comparison.

Wilduck 12y ago

Some people are sayint this is extremely non idiomatic python. I think most of the problem is not following the style guides. Here's a pep8 compliant solution that is a bit more idomatic, and almost as compact. In Python, the way to do pattern matching is with dictionaries of functions. fizz_buzz = {(True, True): lambda x: "Fizzbuzz", (True, False): lambda x: "Fizz", (False, True): lambda x: "Buzz", (False, False): lambda x: x} for i in range(1, 30): fbsign = (i % 3 == 0, i % 5 == 0) print(fizz_buzz[fbsign](i))

tel 12y ago
That's not genuinely pattern matching, however. It only works for patterns without member binding.
- deleted 12y ago
  [deleted]
bluecalm 12y ago
I see it as over thinking simple stuff. Maybe I think about performance too much but constructing a dictionary and then defining functions to do simple signature thing is imo just over designing things. Too much abstraction for expressing a simple concept. Performance aside, you need to go find the dictionary once you see code like that while with chain of if-else statements it's right there in front of your eyes. As to 0 and 1 thing... Python has C'ish boolean (basically an integer type). Using True and False as numbers is completely standard as PEP 285 indicates. I tend to agree that maybe here using True/False is a bit more natural but it really is type-purity nitpick in my view. Could you point out which part of PEP8 the code in my original post violates? While I don't really like a lot of currently popular style I see a lot of values in following the PEP's and long established conventions.