Python中的运算符、数据类型、字符串及列表操作举例，,1.运算符（1）算术

Python中的运算符、数据类型、字符串及列表操作举例，,1.运算符（1）算术

1.运算符

（1）算术运算符：

（2）关系运算符：

（3）赋值运算符：

（4）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.

a=3.0round(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

c=2.555d=1.545print(round(c,2))print(round(d,2))2.561.54

布尔类型：

TrueFalse

3.字符串

dir()查看有哪些内置方法

type()查看是什么类型

str1='aaaaabasdfxqs353235asdf'print(str1.find('fxq'))9str1='aaaaabasdfxqs353235asdf'print(str1.replace('fxq','Fengxiaoqing'))aaaaabasdFengxiaoqings353235asdfstr1='aaaaabasdfxqs353235asdf'print(str1.split('s'))['aaaaaba','dfxq','353235a','df']str1='aaaaabasdfxqs353235asdf'print('SSS'.join(str1.split('s')))aaaaabaSSSdfxqSSS353235aSSSdfa='aaaaabasdfxqs353235asdf'print(a.strip())print(a)print(a.lstrip())#去掉左边空格print(a.rstrip())#去掉右边空格aaaaabasdfxqs353235asdfaaaaabasdfxqs353235asdfaaaaabasdfxqs353235asdfaaaaabasdfxqs353235asdfformat()方法:name='fengxiaoqing'age=30home='chengde'print('hello'+name)print('hello{0}').format(name)print('hello%s')%nameprint('hello%d')%ageprint('我的年龄是：{0}我的家:{1}').format(age,home)print('{name}:{age}'.format(name='fxq',age=20))hellofengxiaoqinghellofengxiaoqinghellofengxiaoqinghello30我的年龄是：30我的家:chengdefxq:20

4.list操作

'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=[123,'bbb','ace']print(a[1])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']################################################################################bbb1[123,'aaa','bbb','ace'][123,'aaa','ace','bbb']['bbb','ace','aaa',123][123,'aaa','ace','bbb','ooo'][123,'aaa','ace','bbb']['aaa','ace','bbb']['aaa','bbb']

列表切片：

a=[11,'222','33',444,555,666]print(a[3:])print(a[1:5])print(a[1:6:2])print(a[:4])print(a[-1])print(a[-2:])print(a[-4:-2])[444,555,666]['222','33',444,555]['222',444,666][11,'222','33',444]666[555,666]['33',444]

Python中的运算符、数据类型、字符串及列表操作举例