Learning with python: Chapter2 Variables, expressions and statements

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　　20个关键词：

　　and def exec if not return assert del finally import or trybreak elif for in pass while class else from is print yield continue except global lambda raise
　　

　　[iyunv@CentOS python]# python
Python 2.6.6 (r266:84292, Feb 21 2013, 23:54:59)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-3)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> print 4 # use print
4
>>> type("Hello world!") # use type()
<type 'str'>
>>> type(3.2)
<type 'float'>
>>> print 1,000,000 # use , operator printmulti-variables
1 0 0
>>> Message="What's up?" # string
>>> n=17
>>> pi=3.1415926
>>> print Message # print string
What's up?
>>> print n
17
>>> print pi
3.1415926
>>> type(Message),type(n),type(pi)
(<type 'str'>, <type 'int'>, <type 'float'>)
>>> 1+1
2
>>> 17
17
>>> Message # string, compare with "print string"
"What's up?"
>>> 5**2,4*3 # ** is exponent and * is multiply
(25, 12)
>>> minute=59
>>> minute/60 # round off
0

　　>>> minute*100/60
98
>>> 3*1**3 # ** is prior to *
3
>>> (3*1)**3
27
>>> print Message + "Ted." # operate string
What's up?Ted.
>>> print Message*3 # print Message for 3 times
What's up?What's up?What's up?
　　>>> percentage=(minute*100)//60 # // is same as / as a division operator
>>> percentage
98
>>> percentage=(minute*100)/60
>>> percentage
98