s = "asdfer"

index = 0

while index < int(len(s)):

    a = s[index]

    print(a)

    index += 1

s = "asdfer"

for i in s:

    print(i)

content = input("请输入式子：")

index = content.find("+")

a = int(content[0:index])

b = int(content[index + 1:])

print(a + b)

content = input ("请输入内容：")

count = 0

for i in content:

    if i.isdigit():

        count += 1

print("数字的个数为：{}" .format(count))

li = ["林风", ["林彬", "赖玉英", "赖狗屎"], "林静", "林圣翔", "林鹏"]

li[1][0] = li[1][0].replace("彬", "兵")

print(li)

# 方法一：

lis = [2, 3, "k", ["qwe", 20, ["k1", ["tt", 3, ""]], 89], "ab", "adv"]

lis[3][2][1][0] = lis[3][2][1][0].upper()

print(lis)

# 方法二：

lis = [2, 3, "k", ["qwe", 20, ["k1", ["tt", 3, ""]], 89], "ab", "adv"]

lis[3][2][1][0] = lis[3][2][1][0].replace("t", "T")

print(lis)