列表（list）的增、删、改、查。range自定义数组。1.24日

     join

# s='alexwusir'
# print('*'.join(s))
# 输出：a*l*e*x*w*u*s*i*r

     计算用户输入的有多少整数？isdigit:判断字符串只由数字组成

content=input('输入：')
count=0
for i in content:
    if i.isdigit():
        count+=1
print(count)

    append 增加

l1=['123','aas',456,'qwe']
while True:
    a=input('/Q或q退出')
    if a.upper()=='Q':break
    l1.append(a)
    print(l1)
print(l1)

insert:插入

l1=['123','aas',456,'qwe']
l1.insert(2,'kwe')
print(l1)
输出：['123', 'aas', 'kwe', 456, 'qwe']
l1=['123','aas',456,'qwe']
l1.insert(0,123)
print(l1)
输出：[123, '123', 'aas', 456, 'qwe']
l1=['123','aas',456,'qwe']
l1.extend('qwert')
print(l1)
输出：['123', 'aas', 456, 'qwe', 'q', 'w', 'e', 'r', 't']

extend:

l1=['123','aas',456,'qwe']
l1.extend([1,2,44,5])
print(l1)
输出：['123', 'aas', 456, 'qwe', 1, 2, 44, 5]

pop:删除。有返回值。

l1=['123','aas',456,'qwe']
l1.pop()
print(l1)
输出：['123', 'aas', 456]
l1.pop(0)
print(l1)
输出：['aas', 456, 'qwe']
l1=['123','aas',456,'qwe']
a=l1.pop(2)
print(a)
输出：456   （有返回值）
print(l1)
输出：['123', 'aas', 'qwe']

remove:按照元素去删除。

l1=['123','aas',456,'qwe']
l1.remove('123')
print(l1)
输出：['aas', 456, 'qwe']
l1.remove(456)
print(l1)
输出：['123', 'aas', 'qwe']

clear 清空列表

l1=['123','aas',456,'qwe']
l1.clear()
print(l1)
输出：[]

del：功能1，删除列表。

l1=['123','aas',456,'qwe']
del l1
print(l1)
del:功能2，可以按照切片，按照索引去删除
l1=['123','aas',456,'qwe']
del l1[0:3]
print(l1)
输出：['qwe']

改，按索引改

l1=['123','aas',456,'qwe']
l1[0]=345
print(l1)
输出：[345, 'aas', 456, 'qwe']
按切片改
l1=['123','aas',456,'qwe']
l1[0:2]=['sb',567]
print(l1)
输出：['sb', 567, 456, 'qwe']

查  按切片，按索引查

l1=['123','aas',456,'qwe']
print(l1[:3])
输出：['123', 'aas', 456]
for循环查
l1=['123','aas',456,'qwe']
for i in l1:
    print(i)
输出：123
      aas
      456
      qwe

len,长度。count,出现次数。

l1=['123','aas',456,'qwe']
print(len(l1))
输出：4
l1=['123','aas',456,'qwe']
ret=l1.count(456)
print(ret)
输出：1

index：通过元素找索引

l1=['123','aas',456,'qwe']
print(l1.index(456))
输出：2

sort 从小到大

l2=[1,3,4,2,6,5,8]
l2.sort()
print(l2)
输出：[1, 2, 3, 4, 5, 6, 8]
sort(reverse)  从大到小
l2=[1,3,4,2,6,5,8]
l2.sort(reverse=True)
print(l2)
输出：[8, 6, 5, 4, 3, 2, 1]

reverse()  倒叙

l2=[1,3,4,2,6,5,8]
l2.reverse()
print(l2)
输出：[8, 5, 6, 2, 4, 3, 1]

首字母大写

l1=['小新','alex','wusir',[1,'taibai','ritian',2]]
l1[1]=l1[1].capitalize()
print(l1[1])
输出：Alex

大写

l1=['小新','alex','wusir',[1,'taibai','ritian',2]]
l=l1[3]
s=(l[1].upper())
l1[3][1]=s
print(s)
输出：TAIBAI

循环打印每一个元素，遇到列表再打印里面的

l1 = [1,2,3,'alex',[2,3,'wusir'],7]
for i in l1:
    if type(i)==list:
        for j in i:
            print(j)
    else:print(i)

li = [1,3,4,'alex',[3,7,8,'taibai'],5,'ritian']
for i in range(0,len(li)):
    if type(li[i]) == list:
        for j in li[i]:
            print(j)
    else:
         print(li[i])

l1 = [1,2,3,'alex',[2,3,'wusir'],7,4,5,8,9,1]
for i in range(0,len(l1)):
    if type (l1[i])==list:
        for a in l1[i]:
            print(a)
    else:
        print(l1[i])

range的用法：指定范围，生成指定数字。范围列表[],列表中的元素是数字,且可控的有效数字范围,一般与for 配合使用

or i in range(1,5):
    print(i)             #运行结果：1234
for i in range(4):
    print(i)             #运行结果：0123
for i in range(1,10,2):
    print(i)             #运行结果：13579
for i in range(5,0,-1):
    print(i)             #运行结果：54321
for i in range(5,-2,-1):
    print(i)             #运行结果：543210-