python之列表

目录

下标

in ,not in 判断是否存在

列表的增加

删除

修改数据

循环

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下标

name_list = ['Tom', 'Lily', 'Rose']
print(name_list[0]) # Tom
print(name_list[1]) # Lily
print(name_list[2]) # Rose

index,count,len

index() count() len()有角标的都有此方法

其中js中index()传入的是角标 python是某个具体的值 且有开始结尾范围

count()传入的是某个具体的值 且有开始结尾范围 出现的次数

name_list = ['Tom', 'Lily', 'Rose']
print(name_list.index('Tom')) # 0
print(name_list.count('Tom')) # 1
print(len(name_list)) # 3

in ,not in 判断是否存在

name_list = ['Tom', 'Lily', 'Rose']
print('tom' in name_list) # False
print('tom' not in name_list) # True

类似js的for in 循环

列表的增加

append 更改了原数组

name_list = ['Tom', 'Lily', 'Rose']
name_list.append('zndroid')
print(name_list) # ['Tom', 'Lily', 'Rose', 'zndroid']

name_list = ['Tom', 'Lily', 'Rose']
name_list.append('zndroid')
name_list.append(['haha','hehe'])
print(name_list) # ['Tom', 'Lily', 'Rose', 'zndroid', ['haha', 'hehe']]

extend 继承添加  适合类型一致的数据类型追加

name_list = ['Tom', 'Lily', 'Rose']
name_list.extend('zndroid')
name_list.extend(['haha','hehe'])
print(name_list) 
# ['Tom', 'Lily', 'Rose', 'z', 'n', 'd', 'r', 'o', 'i', 'd', 'haha', 'hehe']

insert(下标,数据) 插入数据

name_list = ['Tom', 'Lily', 'Rose']
name_list.insert(0,'zndroid')
print(name_list)
# ['zndroid', 'Tom', 'Lily', 'Rose']

删除

del  删除指定位置的数据  del 列表

name_list = ['Tom', 'Lily', 'Rose']
del name_list[0]
print(name_list)
#['Lily', 'Rose']

pop 删除指定位置的数据 默认删除最后一位，并返回删除的数据  列表.pop(x)

name_list = ['Tom', 'Lily', 'Rose']
name=name_list.pop()
print(name)
print(name_list)

# Rose
# ['Tom', 'Lily']

remove 删除指定项

name_list = ['Tom', 'Lily', 'Rose']
name_list.remove('Tom')
print(name_list)
# ['Lily', 'Rose']

clear 清空数据 

修改数据

角标修改

name_list = ['Tom', 'Lily', 'Rose']
name_list[0]='zndroid'
print(name_list)
# ['zndroid', 'Lily', 'Rose']

reverse 反着排

name_list = ['Tom', 'Lily', 'Rose']
name_list.reverse()
print(name_list)
# ['Rose', 'Lily', 'Tom']

sort() 排序 默认正序

name_list = ['Tom', 'Lily', 'Rose']
name_list.sort()
print(name_list)
# ['Lily', 'Rose', 'Tom']
name_list.sort(reverse=True)
print(name_list)
#['Tom', 'Rose', 'Lily']

copy 复制

name_list = ['Tom', 'Lily', 'Rose']
name=name_list.copy()
print(name)
#['Tom', 'Lily', 'Rose']

循环

简单循环

name_list = ['Tom', 'Lily', 'Rose']
i=0
while i< len(name_list):
    print(name_list[i])
    i+=1
for x in name_list:
    print(x)