Single quotes vs. double quotes in Python [closed]

Answer 1

Quoting the official docs at https://docs.python.org/2.0/ref/strings.html:

In plain English: String literals can be enclosed in matching single quotes (') or double quotes (").

So there is no difference. Instead, people will tell you to choose whichever style that matches the context, and to be consistent. And I would agree - adding that it is pointless to try to come up with "conventions" for this sort of thing because you'll only end up confusing any newcomers.

Answer 2

It's probably a stylistic preference more than anything. I just checked PEP 8 and didn't see any mention of single versus double quotes.

I prefer single quotes because its only one keystroke instead of two. That is, I don't have to mash the shift key to make single quote.

Answer 3

I use double quotes in general, but not for any specific reason - Probably just out of habit from Java.

I guess you're also more likely to want apostrophes in an inline literal string than you are to want double quotes.

Answer 4

I used to prefer ', especially for '''docstrings''', as I find """this creates some fluff""". Also, ' can be typed without the Shift key on my Swiss German keyboard.

I have since changed to using triple quotes for """docstrings""", to conform to PEP 257.

Answer 5

In Perl you want to use single quotes when you have a string which doesn't need to interpolate variables or escaped characters like \n, \t, \r, etc.

PHP makes the same distinction as Perl: content in single quotes will not be interpreted (not even \n will be converted), as opposed to double quotes which can contain variables to have their value printed out.

Python does not, I'm afraid. Technically seen, there is no $ token (or the like) to separate a name/text from a variable in Python. Both features make Python more readable, less confusing, after all. Single and double quotes can be used interchangeably in Python.

Answer 6

I aim to minimize both pixels and surprise. I typically prefer ' in order to minimize pixels, but " instead if the string has an apostrophe, again to minimize pixels. For a docstring, however, I prefer """ over ''' because the latter is non-standard, uncommon, and therefore surprising. If now I have a bunch of strings where I used " per the above logic, but also one that can get away with a ', I may still use " in it to preserve consistency, only to minimize surprise.

Perhaps it helps to think of the pixel minimization philosophy in the following way. Would you rather that English characters looked like A B C or AA BB CC? The latter choice wastes 50% of the non-empty pixels.