pprint(): how to use double quotes to display strings?

问题

If I print a dictionary using pprint, it always wraps strings around single quotes ('):

>>> from pprint import pprint
>>> pprint({'AAA': 1, 'BBB': 2, 'CCC': 3})
{'AAA': 1, 'BBB': 2, 'CCC': 3}

Is there any way to tell pprint to use double quotes (") instead? I would like to have the following behaviour:

>>> from pprint import pprint
>>> pprint({'AAA': 1, 'BBB': 2, 'CCC': 3})
{"AAA": 1, "BBB": 2, "CCC": 3}

回答1:

It looks like you are trying to produce JSON; if so, use the json module:

>>> import json
>>> print json.dumps({'AAA': 1, 'BBB': 2, 'CCC': 3})
{"AAA": 1, "BBB": 2, "CCC": 3}

The pprint() function produces Python representations, not JSON and quoting styles are not configurable. Don’t confuse the two syntaxes. JSON may at first glance look a lot like Python but there are more differences than just quoting styles:

JSON is limited to a few specific types only ({...} objects with key-value pairs, [...] arrays, "..." strings, numbers, booleans and nulls). Python data structures are far richer.
Python dictionary keys can be any hashable object, JSON object keys can only ever be strings.
JSON booleans are written in lowercase,true and false. Python uses title-case, True and False.
JSON uses null to signal the absence of a value, Python uses None.
JSON strings use UTF-16 codepoints, any non-BMP codepoint is encoded using surrogate pairs. Apart from a handful of single-letter backslash escapes such as \n and \" arbitrary codepoint escapes use \uXXXX 16-bit hexadecimal notation. Python 3 strings cover all of Unicode, and the syntax supports \xXX, \uXXXX, and \UXXXXXXXX 8, 16 and 32-bit escape sequences.

If you want to produce indented JSON output (a bit like pprint() outputs indented Python syntax for lists and dictionaries), then add indent=4 and sort_keys=True to the json.dumps() call:

>>> print json.dumps({'AAA': 1, 'CCC': 2, 'BBB': 3}, indent=4, sort_keys=True)
{
    "AAA": 1,
    "BBB": 2,
    "CCC": 3
}

See http://stackoverflow.com/questions/12943819/how-to-python-prettyprint-a-json-file

来源：https://stackoverflow.com/questions/16087662/pprint-how-to-use-double-quotes-to-display-strings

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python

pretty-print

pprint