直播4-打印o的位置

# 打印每个o出现的位置
str1 = "hellopythonhelloworld"
str2 = ‘hellopythonhelloworld‘
str3 = ‘hellopythonhelloworl‘
index = 0
for i in str1:
    if i == ‘o‘:
        print(index, end=‘\t‘)
    index += 1

# 枚举实现
str1 = ‘hellopythonhelloworl‘
for i, j in enumerate(list(str1)):
    if j == ‘o‘:
        print(i)

# # 实现用户登录校验功能
# # 要求：分别提示用户输入用户名和密码，当用户名为seven，密码为123或用户名为alex密码为456时，显示登陆成功，并结束程序；否则显示登陆失败并提示用户重新输入用户名和密码.
# # PS：用户只有3次登录校验的机会，第3次登录失败则结束程序。
#
names = [‘alex‘, ‘seven‘]
passwords = [‘123‘, ‘456‘]
count = 1
while True:
    name = input(‘your name:‘)
    password = input(‘your password:‘)
    if name in names and password in passwords:
        print(‘wellcome log in‘)
        break
    else:
        print(‘fail to log please try again‘)
        count += 1
        if count > 3:
            break

# 编写函数，实现接收一个字符串，分别统计大写字母、小写字母、数字字符的个数。
str_a = "Java324javaajlsdf56sdfja54@vajav345aa234ddsfa987dsjkp132132jp324"
count_number = 0
count_lower = 0
count_upper = 0
for i in range(0, len(str_a)):
    if str_a[i].isdigit():
        count_number += 1
    if str_a[i].islower():
        count_lower += 1
    if str_a[i].isupper():
        count_upper += 1
print(‘数字有%d个‘ % (count_number))
print(‘小写字母有%d个‘ % (count_lower))
print(‘大写字母有%d个‘ % (count_upper))