Exercise: data type of string

1. enter a string of characters printed on all odd bit (subscripted characters on bits 1,3,5,7 ...)

For example: Enter 'abcd1234' output 'bd24'

str1 = input('请输入字符串：')
for index1 in range(len(str1)):
    if index1 % 2 == 1:
        print(str1[index1])

2. Enter the user name, the user name is valid is determined (user name length of 6 to 10)

name1 = input('请输入用户名：')
while True:
    if 6 <= len(name1) <= 10:
        print('用户名合法，欢迎！')
        break
    else:
        print('用户名不合法')
    name1 = input('请输入用户名：')

3. Enter the user name, user name to determine the legality of (the user name only by numbers and letters)

For example: 'abc' - legal '123' - legal 'abc123a' - legitimate

'''方法①'''
name2 = input('请输入用户名：')
for name_2 in name2:
    if not ('0' <= name_2 <= '9' or 'A' <= name_2 <= 'Z' or 'a' <= name_2 <= 'z'):
        print('不合法')
        break
else:
    print('合法')

'''方法②'''
name2 = input('请输入用户名：')
for name_2 in name2:
    if name_2.isalnum() == False:
        print('不合法')
        break
else:
    print('合法')

4. Enter your user name, user name to determine the legality (username and must contain only contain numbers and letters, and the first character must be a capital letter)

For example: 'abc' - not legal '123' - not legal 'abc123' - not legal 'Abc123ahs' - legitimate

name3 = input('请输入用户名：')
for name_3 in name3:
    if not 'A' <= name3[0] <= 'Z':
        print('不合法')
        break
    elif not ('0' <= name_3 <= '9' or 'A' <= name_3 <= 'Z' or 'a' <= name_3 <= 'z'):
        print('不合法')
        break
    elif name3.isalpha() == True or name3.isdigit() == True:
        print('不合法')
        break
else:
    print('合法')

# 5. Enter a string, numeric character string taken out all produce a new string

For example: Enter 'abc1shj23kls99 + 2kkk' Output: '123992'

str2 = input('请输入：')
list1 = []
for value1 in str2:
    if '0' <= value1 <= '9':
        list1.append(value1)
print(list1)
print(''.join(list1))

6. Enter a string, the string in all lowercase letters capitalized corresponding to the output (by the method and upper two ways to write algorithms)

For example: Enter 'a2h2klm12 +' output 'A2H2KLM12 +'

str3 = input('请输入：')
print(str3.upper())
list2 = []
for value2 in str3:
    if 'a' <= value2 <= 'z':
        list2.append(chr(ord(value2) - 32))
        continue
    list2.append(value2)
print(''.join(list2))

7. Enter a number less than 1000, to produce the corresponding number of school

For example: Enter '23', the output 'py1901023' enter '9', outputs 'py1901009' input '123', outputs 'py1901123'

num1 = input('请输入数字：')
print('py1906', num1.rjust(3, '0'), sep='')
print('py1906', num1.zfill(3), sep='')

8. Enter a string, counting the number of strings of alphanumeric characters Africa

For example: Enter 'anc2 + 93-sj nonsense' output: Input 4 '===' Output: 3

str3 = input('请输入：')
count1 = 0
for oth in str3:
    if not ('0' <= oth <='9' or 'A' <= oth <= 'Z' or 'a' <= oth <= 'z'):
        count1 +=1
print(count1)

9. The input string, the beginning and end of the string into the '+', generating a new string

For example: input string 'abc123', output '+ bc12 +'

str4 = input('请输入：')
str5 = str4.replace(str4[0], '+')
print(str5.replace(str5[-1], '+'))

10. The input string, access the string of characters intermediate

For example: Enter 'ABC1234' Output: '1' input 'abc123' output 'C1'

str6 = input('请输入：')
if int(len(str6)) & 1 == 1:
    print(str6[int(len(str6)//2)])
elif int(len(str6)) & 1 == 0:
    print(str6[int(len(str6) // 2 - 1)], str6[int(len(str6) // 2)])

11. Write program implements string functions find / index features (to get the string 2 position of the first occurrence of a string)

For example: string 1 is: how are you Im fine, Thank you !, string 2:? You, print 8

str7 = 'how are you? Im fine, Thank you!'
str8 = 'you'
for index7 in range(len(str7)):
    n = 0
    for index8 in range(len(str8)):
        if str7[index7] == str8[0]:
            if str7[index7 + 1] == str8[1]:
                print(index7)
                n += 1
                break
    if n == 1:
        break

12. Obtain two character strings in common

For example: string 1 is: abc123, string 2: huak3, printing: common character has: A3

str9 = 'abc123'
str10 = 'huak3'
set1 = set()
for value9 in str9:
    for value10 in str10:
        if value9 == value10:
            set1.add(value9)
print('公共字符有:',''.join(set1))