lists and Dictionaries

>>> print {i : chr(65+i) for i in range(4)}
    {0 : 'A', 1 : 'B', 2 : 'C', 3 : 'D'}

    >>> print {k : v for k, v in someDict.iteritems()} == someDict.copy()
    1

    >>> print {x.lower() : 1 for x in list_of_email_addrs}
    {'barry@zope.com'   : 1, 'barry@python.org' : 1, 'guido@python.org' : 1}

    >>> def invert(d):
    ...     return {v : k for k, v in d.iteritems()}
    ...
    >>> d = {0 : 'A', 1 : 'B', 2 : 'C', 3 : 'D'}
    >>> print invert(d)
    {'A' : 0, 'B' : 1, 'C' : 2, 'D' : 3}

    >>> {(k, v): k+v for k in range(4) for v in range(4)}
    ... {(3, 3): 6, (3, 2): 5, (3, 1): 4, (0, 1): 1, (2, 1): 3,
         (0, 2): 2, (3, 0): 3, (0, 3): 3, (1, 1): 2, (1, 0): 1,
         (0, 0): 0, (1, 2): 3, (2, 0): 2, (1, 3): 4, (2, 2): 4, (
         2, 3): 5}

  

原文地址:https://www.cnblogs.com/wangwenfei/p/python.html