JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式。它基于JavaScript的一个子集。 JSON采用完全独立于语言的文本格式，但是也使用了类似于C语言家族的习惯（包括C, C++, C#, Java, JavaScript, Perl, Python等）。这些特性使JSON成为理想的数据交换语言。易于人阅读和编写，同时也易于机器解析和生成。

编码：把一个Python对象编码转换成Json字符串   json.dumps()

解码：把Json格式字符串解码转换成Python对象   json.loads()

我也想知道json.dumps（）是什么函数？

Help on function dumps in module json:

dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None, separators=None, encoding='utf-8', default=None, sort_keys=False, **kw)
   Serialize ``obj`` to a JSON formatted ``str``.
   
   If ``skipkeys`` is false then ``dict`` keys that are not basic types
   (``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)
   will be skipped instead of raising a ``TypeError``.
   
   If ``ensure_ascii`` is false, all non-ASCII characters are not escaped, and
   the return value may be a ``unicode`` instance. See ``dump`` for details.
   
   If ``check_circular`` is false, then the circular reference check
   for container types will be skipped and a circular reference will
   result in an ``OverflowError`` (or worse).
   
   If ``allow_nan`` is false, then it will be a ``ValueError`` to
   serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``) in
   strict compliance of the JSON specification, instead of using the
   JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).
   
   If ``indent`` is a non-negative integer, then JSON array elements and
   object members will be pretty-printed with that indent level. An indent
   level of 0 will only insert newlines. ``None`` is the most compact
   representation.  Since the default item separator is ``', '``,  the
   output might include trailing whitespace when ``indent`` is specified.
   You can use ``separators=(',', ': ')`` to avoid this.
   
   If ``separators`` is an ``(item_separator, dict_separator)`` tuple
   then it will be used instead of the default ``(', ', ': ')`` separators.
   ``(',', ':')`` is the most compact JSON representation.
   
   ``encoding`` is the character encoding for str instances, default is UTF-8.
   
   ``default(obj)`` is a function that should return a serializable version
   of obj or raise TypeError. The default simply raises TypeError.
   
   If *sort_keys* is ``True`` (default: ``False``), then the output of
   dictionaries will be sorted by key.
   
   To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
   ``.default()`` method to serialize additional types), specify it with
   the ``cls`` kwarg; otherwise ``JSONEncoder`` is used.

import jsom
help(jsom.dumps)