Python FAQ

@1: [raw_input & input]

在python 3版本上运行是OK的，但一到2.7版本上运行就出现了下面的问题：

ERROR:

Traceback (most recent call last):
File "<pyshell#1>", line 1, in <module>
input_A = input("Input: ")
File "<string>", line 1, in <module>
NameError: name 'abc' is not defined

Answer: http://www.cnblogs.com/way_testlife/archive/2011/03/29/1999283.html

@2: 2014/3/16

>>> myDict = {'a' : '1', 'b' : '2'}
>>> myDict
{'a': '1', 'b': '2'}
>>> myDict['a']
'1'
>>> myDict['1']　　# ERROR
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
KeyError: '1'
>>> myDict.get('a')
'1'
>>> myDict.get('1')　　# return None. NO ERROR. Compare with myDict['1'] on the front
>>> myDict['1'] = ['a', 'b']　　# NO ERROR. Compare with myDict['1'] on the front 
>>> myDict 
{'a': '1', '1': ['a', 'b'], 'b': '2'}