Python数据类型的操作——列表、元组

一、列表的索引和切片

li = ['a','b','c',1,2,3]
print(li[0])
print(li[2])
print(li[-1])
# a
# c
# 3
#切片
print(li[0:3])
print(li[2:5])
print(li[0:5:2])
# ['a', 'b', 'c']
# ['c', 1, 2]
# ['a', 'c', 2]

二、增

2.1、append(self, p_object)  添加

Demo = ['name','age','job']
Demo.append('hobby')     #在列表后面新增元素 
print(Demo)
Demo.append([1,'hehe',True])
print(Demo)                            #直接添加整个列表
# ['name', 'age', 'job', 'hobby']
# ['name', 'age', 'job', 'hobby', [1, 'hehe', True]]

2.2、insert(self,  index, p_object)  插入

Demo = ['name','age','job']
Demo.insert(1,'kitty')    #通过索引插入
print(Demo)
# ['name', 'kitty', 'age', 'job']

nsert()只能通过 索引 插入

2.3、extend(self,  iterable)

在列表后面   可迭代 的添加

Demo = ['name','age','job']
Demo.extend(' ')
print(Demo)
# ['name', 'age', 'job', ' ']
Demo = ['name','age','job']
Demo.extend('a')
print(Demo)
# ['name', 'age', 'job', 'a']
Demo = ['name','age','job']
Demo.extend('abc')          #可迭代的对象拆分遍历后添加
print(Demo)
# ['name', 'age', 'job', 'a', 'b', 'c']
Demo = ['name','age','job']
Demo.extend(['abc','b','c'])   #可迭代的对象拆分(子序列)遍历后添加
print(Demo)
# ['name', 'age', 'job', 'abc', 'b', 'c']

三、删

3.1、pop(self, index=None)  

通过索引删除

Demo = ['name','age','job']
t = Demo.pop(1)    #pop(索引)
print(Demo)
print(t)
# ['name', 'job']
# age

3.2、remove(self, value)

直接删除看到的值

Demo = ['name','age','job']
Demo.remove('age')
print(Demo)
# ['name', 'job']

3.3、clear(self)

清空列表

Demo = ['name','age','job']
Demo.clear()
print(Demo)
# []

3.4、del  

删除

Demo = ['name','age','job','wall_e','eva',1,2,3]
del Demo[2]     #索引删除
print(Demo)
# ['name', 'age', 'wall_e', 'eva', 1, 2, 3]
Demo = ['name','age','job','wall_e','eva',1,2,3]
del Demo[2:6:2]   #切片删除
print(Demo)
# ['name', 'age', 'wall_e', 1, 2, 3]
Demo = ['name','age','job','wall_e','eva',1,2,3]
del Demo               #把列表删了，列表不存在了，报错   not defined
print(Demo)
# Traceback (most recent call last):
#   File "D:/Demo/test.py", line 11, in <module>
#     print(Demo)
# NameError: name 'Demo' is not defined

四、改

4.1 通过索引改

4.2 通过切片改     （添加可迭代的对象）

Demo = ['name','age','job','wall_e','eva',1,2,3]
Demo[2] = 'hobby'
print(Demo)
# ['name', 'age', 'hobby', 'wall_e', 'eva', 1, 2, 3]
Demo = ['name','age','job','wall_e','eva',1,2,3]
Demo[2:5:] = 'abcde'
print(Demo)
# ['name', 'age', 'a', 'b', 'c', 'd', 'e', 1, 2, 3]

五、查

通过索引查

通过切片查

通过for循环 列出查看

Demo = ['name','age','job','wall_e','eva',1,2,3]
print(Demo[2])
# job
print(Demo[5:0:-2])
# [1, 'wall_e', 'age']

li = ['aefc','df',1,5,3]
for i in li:
    print(i)
# aefc
# df
# 1
# 5
# 3

###枚举 enumerrate(self, iterable, start = 0)

iterable:   str,  list,    tuple,    dict,    set  

li = ['a','b','c','d']
for i in enumerate(li):
    print(i)
# (0, 'a')
# (1, 'b')
# (2, 'c')
# (3, 'd')
for i in enumerate(li,6)
(# (6, 'a')
# (7, 'b')
# (8, 'c')
# (9, 'd')

六、index()

通过值 取 索引

七、count   计数

Demo = ['name','age',['name','wall_e','name',1],2,'name']
print(Demo.count('name'))
# 2
print(Demo.count('haha'))
# 0

八、排序

sort(self, key=None, reverse=False) 正序
sort(reverse=True) 倒序

Demo = [1,2,3,7,6,0,4,5]
Demo.sort()
print(Demo)
Demo = [1,2,3,7,6,0,4,5]
Demo.sort(reverse=True)
print(Demo)
# [0, 1, 2, 3, 4, 5, 6, 7]
# [7, 6, 5, 4, 3, 2, 1, 0]

九、reverse(self)     反转

Demo = [1,2,3,7,6,0,4,5]
Demo.reverse()
print(Demo)
# [5, 4, 0, 6, 7, 3, 2, 1]

###  将字符串转换成列表，split
将列表转换成字符串，join （列表的每个值都是字符串）

b = ['a','b','c']
a = '_'.join(b)
print(a)
# a_b_c

a = 'Tom'
b = '5'.join(a)
print(b)
# T5o5m

十、列表的嵌套

Demo = ['name','age',['job','wall_e','eva',1],2,3]
Demo[1] = 'AGE'
print(Demo)
# ['name', 'AGE', ['job', 'wall_e', 'eva', 1], 2, 3]
Demo = ['name','age',['job','wall_e','eva',1],2,3]
Demo[1] = Demo[1].upper()
print(Demo)
# ['name', 'AGE', ['job', 'wall_e', 'eva', 1], 2, 3]
#***必须把新生成的AGE 替换掉原来的，  （通过索引改）
Demo = ['name','age',['job','wall_e','eva',1],2,3]
Demo[2][2] = Demo[2][2].upper()
print(Demo)
# ['name', 'age', ['job', 'wall_e', 'EVA', 1], 2, 3]

#列表元素  首字母大写
Demo = ['name','age',['job','wall_e','eva',1],2,3]
Demo[0].capitalize()
print(Demo)
print(Demo[0].capitalize())
# ['name', 'age', ['job', 'wall_e', 'eva', 1], 2, 3]
# Name
#不替换新的元素，原列表是不变的，即使列表是可变类型，因为字符串是不可变类型，
#对字符串的操作不会改变原字符串
Demo[0] = Demo[0].capitalize()
print(Demo)
# ['Name', 'age', ['job', 'wall_e', 'eva', 1], 2, 3]

十一、元组

只读，不可修改
元组不可修改，但是元组如果包含列表，列表的内容可以更改

a = (1,3,5)
a[1] = 9       #报错，tuple 对象不支持更改
print(a)    
# Traceback (most recent call last):
#   File "D:/Demo/test.py", line 2, in <module>
#     a[1] = 9
# TypeError: 'tuple' object does not support item assignment

Demo = ('name','age',['wall_e','name',1],2)
Demo[2][1] = 'job'
print(Demo)
# ('name', 'age', ['wall_e', 'job', 1], 2)

十二、range() 

包含指定范围

for i in range (1,10,2):  #可加步长
    print(i)