模块说明

pprint模块常用于列表、元组和字典数据类型的美化输出。提供的方法包括有pformat()、pprint() 和 saferepr()，其中pprint.pprint()方法最常用，常用来调试，如查看某个特殊对象的内部成员，例，查看math模块的内部成员：pprint.pprint(vars(math))

这个模块还是挺鸡肋的，除了配合ipdb调试的时候会用到其它地方应该不会遇到需要应用的地方。

pprint.pprint()

pprint(object, stream=None, indent=1, width=80, depth=None)：将对象美化输出，indent设置首行缩进的宽度，depth设置显示显示的对象深度既层级。

输出pprint模块中的所有属性及方法，指定深度为1层。

import pprint
pprint.pprint(vars(pprint), depth=1)
'''
{'PrettyPrinter': <class pprint.PrettyPrinter at 0x7f7746d60808>,
 '_StringIO': <built-in function StringIO>,
 '__all__': [...],
 '__builtins__': {...},
 '__doc__': "Support to pretty-print lists, tuples, & dictionaries recursively.\n\nVery simple, but useful, especially in debugging data structures.\n\nClasses\n-------\n\nPrettyPrinter()\n    Handle pretty-printing operations onto a stream using a configured\n    set of formatting parameters.\n\nFunctions\n---------\n\npformat()\n    Format a Python object into a pretty-printed representation.\n\npprint()\n    Pretty-print a Python object to a stream [default is sys.stdout].\n\nsaferepr()\n    Generate a 'standard' repr()-like value, but protect against recursive\n    data structures.\n\n",
 '__file__': '/usr/lib/python2.7/pprint.pyc',
 '__name__': 'pprint',
 '__package__': None,
 '_commajoin': <built-in method join of str object at 0x7f7746d705f8>,
 '_id': <built-in function id>,
 '_len': <built-in function len>,
 '_perfcheck': <function _perfcheck at 0x7f7746d779b0>,
 '_recursion': <function _recursion at 0x7f7746d77938>,
 '_safe_repr': <function _safe_repr at 0x7f7746d77500>,
 '_sorted': <function _sorted at 0x7f7746d77488>,
 '_sys': <module 'sys' (built-in)>,
 '_type': <type 'type'>,
 'isreadable': <function isreadable at 0x7f7746d77398>,
 'isrecursive': <function isrecursive at 0x7f7746d77410>,
 'pformat': <function pformat at 0x7f7746d772a8>,
 'pprint': <function pprint at 0x7f7746d77230>,
 'saferepr': <function saferepr at 0x7f7746d77320>,
 'warnings': <module 'warnings' from '/usr/lib/python2.7/warnings.pyc'>}
'''

pprint.pformat()

pformat(object, indent=1, width=80, depth=None)：和pprint.pprint()方法的区别在于，pprint方法返回对象，pformat方法返回pprint放回的对象的字符串表示形式。

pprint.saferepr()

saferepr(object)：将对象转换成字符串，并通过repr方法处理后返回。