Content-Type: text/x-zim-wiki
Wiki-Format: zim 0.4
Creation-Date: 2012-10-04T13:21:05+08:00

====== dict ======
Created Thursday 04 October 2012

Help on class dict in module __builtin__:

class dict(object)
 |  dict() -> new empty dictionary
 |  dict(mapping) -> new dictionary initialized from **a mapping object**'s   #mapping为__一个__pairs对象
 |      (key, value) pairs
 |  dict(iterable) -> new dictionary initialized as if via:
 |      d = {}
 |      for **k, v** in iterable:    #迭代器对象每次返回的元素必须是一个容器类型，__容器中元素的个数为2__.**如[a,b], **~~"ab"~~**,(a,b)**
 |          d[k] = v
 |  dict(__**kwargs)__ -> new dictionary initialized with the name=value pairs
 |      in the keyword argument list.  For example:  dict(one=1, two=2)
 |  
 |  Methods defined here:


>>> dict(__[('sape', 4139), ('guido', 4127), ('jack', 4098)]__)
{'sape': 4139, 'jack': 4098, 'guido': 4127}

>>> dict([(x, x**2) for x in (2, 4, 6)])     # use a list comprehension
{2: 4, 4: 16, 6: 36}

>>> dict(sape=4139, guido=4127, jack=4098)
{'sape': 4139, 'jack': 4098, 'guido': 4127}
tel = {'jack': 4098, 'sape': 4139}

>>> dc=dict(["df","12"]);dc   #["df","12"]为一科迭代对象，每次返回的元素为两个字符的str，所以可以被unpack给key,value
{'1': '2', 'd': 'f'}
>>> dc=dict(["df",__"123"__]);dc
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: dictionary update sequence element __#1 has length 3; 2 is required__
>>>