Single quotes vs. double quotes in Python [closed]

Question

I like to use double quotes around strings that are used for interpolation or that are natural language messages, and single quotes for small symbol-like strings, but will break the rules if the strings contain quotes, or if I forget. I use triple double quotes for docstrings and raw string literals for regular expressions even if they aren't needed.

For example:

LIGHT_MESSAGES = {
    'English': "There are %(number_of_lights)s lights.",
    'Pirate':  "Arr! Thar be %(number_of_lights)s lights."
}

def lights_message(language, number_of_lights):
    """Return a language-appropriate string reporting the light count."""
    return LIGHT_MESSAGES[language] % locals()

def is_pirate(message):
    """Return True if the given message sounds piratical."""
    return re.search(r"(?i)(arr|avast|yohoho)!", message) is not None

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.

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.

I'm with Will:

• Double quotes for text
• Single quotes for anything that behaves like an identifier
• Double quoted raw string literals for regexps
• Tripled double quotes for docstrings

I'll stick with that even if it means a lot of escaping.

I get the most value out of single quoted identifiers standing out because of the quotes. The rest of the practices are there just to give those single quoted identifiers some standing room.

If the string you have contains one, then you should use the other. For example, "You're able to do this", or 'He said "Hi!"'. Other than that, you should simply be as consistent as you can (within a module, within a package, within a project, within an organisation).

If your code is going to be read by people who work with C/C++ (or if you switch between those languages and Python), then using '' for single-character strings, and "" for longer strings might help ease the transition. (Likewise for following other languages where they are not interchangeable).

The Python code I've seen in the wild tends to favour " over ', but only slightly. The one exception is that """these""" are much more common than '''these''', from what I have seen.