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, "1"]], 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, "1"]], 89], "ab", "adv"]
lis[3][2][1][0] = lis[3][2][1][0].replace("t", "T")
print(lis)