Python中的运算符、数据类型、字符串及列表操作举例
1.运算符http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif（1）算术运算符：
（2）关系运算符：
http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif
http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif（3）赋值运算符：
（4）http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif逻辑运算符：
优先级：() > not > and > or
2.数据类型:
raw_input()： 接收字符串类型
input() : 接收数字类型
整型：
a =-100
abs(a) 求a的绝对值
a.__abs__() 求a的绝对值
符点型:
round()方法 默认保留1位小数,采用四舍五入方法进行计算,最后一位为偶数.
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a = 3.0
round(a)
round(2)
先进行四舍五入运算，如果小数点精度的最后一位是偶数符合条件，如果小数点精度最后一位四舍五入以后为奇数,则舍弃小说点精度以后所有数字，以保证小数点精度，最后一位为偶数
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c = 2.555
d = 1.545
print (round(c,2))
print(round(d,2))
2.56
1.54
布尔类型：
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True
False
3.字符串
http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif
dir()查看有哪些内置方法
type()查看是什么类型
http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gifhttp://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif
http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif
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str1 = 'aaaaabasdfxqs353235asdf'
print (str1.find('fxq'))
9
str1 = 'aaaaabasdfxqs353235asdf'
print (str1.replace('fxq','Fengxiaoqing'))
aaaaabasdFengxiaoqings353235asdf
str1 = 'aaaaabasdfxqs353235asdf'
print (str1.split('s'))
['aaaaaba', 'dfxq', '353235a', 'df']
str1 = 'aaaaabasdfxqs353235asdf'
print ('SSS'.join(str1.split('s')))
aaaaabaSSSdfxqSSS353235aSSSdf
a = ' aaaaabasdfx qs353 235asdf '
print (a.strip())
print (a)
print (a.lstrip()) #去掉左边空格
print(a.rstrip()) #去掉右边空格
aaaaabasdfx qs353 235asdf
aaaaabasdfx qs353 235asdf
aaaaabasdfx qs353 235asdf
aaaaabasdfx qs353 235asdf
format()方法:
name = 'fengxiaoqing'
age = 30
home = 'chengde'
print('hello'+name)
print('hello {0}').format(name)
print('hello %s') % name
print('hello %d') % age
print('我的年龄是：{0} 我的家:{1}').format(age,home)
print('{name}:{age}'.format(name='fxq',age=20))
hellofengxiaoqing
hello fengxiaoqing
hello fengxiaoqing
hello 30
我的年龄是：30 我的家:chengde
fxq:20
4.list操作
http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif
http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif
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'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort'
str1 = '12poqiwrtgopwert'
str2 = list(str1)
print(type(str1))
print(type(str2))
print(list(str1))
print(dir(str2))
print('####'*20)
a =
print(a)
print(a.index('bbb'))
a.insert(1,'aaa')
print(a)
a.sort()
print(a)
a.reverse()
print(a)
a.append('ooo')
print(a)
a.pop()
print(a)
a.remove(123)
print(a)
a.pop(1)
print(a)
<type 'str'>
<type 'list'>
['1', '2', 'p', 'o', 'q', 'i', 'w', 'r', 't', 'g', 'o', 'p', 'w', 'e', 'r', 't']
['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__delslice__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getslice__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']
################################################################################
bbb
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['bbb', 'ace', 'aaa', 123]
['aaa', 'ace', 'bbb']
['aaa', 'bbb']
列表切片：
http://blog.51cto.com/static/js/ueditor1.4.3/themes/default/images/spacer.gif
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a =
print(a)
print(a)
print(a)
print(a[:4])
print(a[-1])
print(a[-2:])
print(a[-4:-2])
['222', '33', 444, 555]
['222', 444, 666]
666
['33', 444]
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