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Comment by RyanMcGreal | Hacker News Reader

I came across this when I was first learning Python and it has always impressed me:

    from random import shuffle
    deck = ['%s of %s' % (number, suit) for number in '2 3 4 5 6 7 8 9 10 Jack Queen King Ace'.split(' ') for suit in 'Hearts Clubs Diamonds Spades'.split(' ')]
    shuffle(deck)

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I never liked how people in Python use stringWithSpaces.split instead of a list. Just feels wrong somehow.

But I've seen it many times so it's probably pythonic

It makes sense when all the values in the list are text.

Avoids lots of ", "

I do it entirely, exclusively, only, purely because it requires less punctuation typing. It returns a list anyway. The performance hit is virtually unnoticeable in almost every use case (unless this is a function taking in input strings formatted this way many times per second, but in that case you've got way worse to worry about first...).

I agree; what I usually do is type the string.split() version in a REPL (I keep one open permanently) and then copy-paste the result to the file.

It avoids having to do a big change if you need to add a new item with spaces in it.

It's like old Perl idiom where Python's 'ab cd ef'.split(), would be written as qw(ab cd ef), which probably looks nicer --'qw' stands for 'quote words', I think.

As DaFranker points out, it's just easier to type than

    ('Hearts', 'Diamonds', 'Spades', 'Clubs')

and has less opportunity for typos and syntax errors. If I was concerned about performance I would replace it with a tuple, but it was Good Enough for a quick example.

Sorry, I realised I sounded negative. Nothing against you, it's just my private opinion.

It's not about performance, but about one more incidental step when reading the code. Small cost, but it's there.

One reason I like it is that you're probably going to be reading in the possible values from a stream or arg or config file anyway.

But you have a good point. YAGNI is YAGNI.

also in the std library, https://docs.python.org/3/library/collections.html#collectio... field_names can take a single space separated string

I love this idiom. I also use it in Javascript.

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