Python基础第一天

一、内容

二、练习

练习1

题目:使用while循环输出1 2 3 4 5 6 8 9 10

 

方法一:

图示:

代码:

count = 1
while count < 11:
    if count != 7:
        print(count)
    count += 1

 输出结果:

1
2
3
4
5
6
8
9
10
View Code

方法二:

图示:

代码:

count = 0
while count < 10:
    count += 1
    if count == 7:
        continue
    print(count)

输出结果:

1
2
3
4
5
6
8
9
10
View Code

练习2

题目:求1-100的所有数的和

图示:

代码:

sum = 0
count = 1
while count < 101:
    sum = sum + count
    count += 1
print(sum)

输出结果:

5050

练习3

题目:输出 1-100 内的所有奇数

图示:

代码:

count = 1
while count < 101:
    if count % 2 != 0:
        print(count)
    count += 1

输出结果:

1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
51
53
55
57
59
61
63
65
67
69
71
73
75
77
79
81
83
85
87
89
91
93
95
97
99
View Code

练习4

题目:输出 1-100 内的所有偶数

图示:

代码:

count = 1
while count < 101:
    if count % 2 == 0:
        print(count)
    count += 1

输出结果:

2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
100
View Code

练习5

题目:求1-2+3-4+5 ... 99的所有数的和

图示:

代码:

count = 1
sum1 = 0
sum2 = 0
while count < 100:
    if count % 2 != 0:
        sum1 = sum1 + count
    else:
        sum2 = sum2 - count
    count += 1
print(sum1 + sum2)

输出结果:

50

练习6

题目:用户登陆(三次机会重试)

步骤一:实现三次登陆的基本功能

图示:

代码:

user = 'knight'
pwd = 'dk123'
count = 1
while True:
    if count == 4:
        print('Too many times!')
        break
    username = input('Please enter your username:')
    password = input('Please enter your password:')
    if username == user and password == pwd:
        print('Login successfully!')
        break
    else:
        print('The username or password you entered is incorrect,Please try again!')
    count += 1

步骤二:去除BUG并添加功能

1、去除用户输入用户名时左右两边的空格

2、判断用户名是否有值,如果没有则反复让用户输入,并提示请输入用户名

3、判断密码是否有值,如果没有则反复让用户输入,提示请输入密码

4、用户每输错一次便告之用户还有多少次机会

图示:

代码:

user = 'knight'
pwd = 'dk123'
count = 1
while True:
    if count == 4:
        print('Too many times!')
        break
    username = input('Please enter your username:').strip()
    password = input('Please enter your password:')
    if not username:
        print('The username you entered is blank, please re-enter')
        continue
    elif not password:
        print('The password you entered is blank, please re-enter')
        continue
    if username == user and password == pwd:
        print('Login successfully!')
        break
    else:
        print('The username or password you entered is incorrect,Please try again!')
        print('You still have %s chances'%(3-count))
    count += 1

  

步骤三:三次登陆锁定

扩展:当同一个用户名的输错次数超过三次时,锁定该用户名

图示:

代码:

user = 'knight'
pwd = 'dk123'
count = 1
times = []  # 用于统计密码输错时的用户名的个数

with open('blacklist.txt', 'r', encoding='utf-8') as f_black:
    black_line = f_black.readlines()   # 将黑名单内容以列表的形式读出来
    # print(black_line)

while True:

    # 当登陆次数超过3次时提示登陆次数过多,退出程序
    if count == 4:
        print('Too many times!')
        break

    username = input('Please enter your username:').strip()
    password = input('Please enter your password:').strip()

    # 判断用户名是否为空
    if not username:
        print('The username you entered is blank, please re-enter')
        continue

    # 判断密码是否为空
    elif not password:
        print('The password you entered is blank, please re-enter')
        continue

    # 判断用户名再加上"
"是否在黑名单的列表里,如果在则提示用户已锁定再退出程序
    if username + '
' in black_line:
        print('Sorry, your account has been locked!')
        break
    
    # 判断用户名和密码是否匹配
    if username == user and password == pwd:
        print('Login successfully!')
        break
    else:
        print('The username or password you entered is incorrect,Please try again!')
        print('You still have %s chances' % (3 - count)) # 如果不匹配则提示用户名或密码错误并告之用户还有几次机会
        
        times.append(username)  # 将错误的用户名加入至事先定义的times列表中,
        if times.count(username) == 3:  # 然后计算加入的用户名的个数是否等于三个,如果是则写入至黑名单文件中。
            with open('blacklist.txt', 'a', encoding='utf-8')as f:
                f.write(username+'
')
    count += 1

练习7

题目:猜年龄

步骤一:实现基本逻辑

图示:

代码:

age = 28
while True:
    user = int(input('Please enter a number:')) # 强转为整型
    if user > age:
        print('Try smaller!')
    elif user < age:
        print('Try bigger!')
    else:
        print('You got it!')
        break

步骤二:去除BUG并添加功能

1、去除BUG,当用户输入其它字符时让其重新输入

2、添加猜错时给予三次机会功能

图示:

代码:

age = 28
count = 0
while True:
    if count == 3:
        print('You guess too many times')
        break

    user = input('Please enter a number:').strip()
    if not user.isdigit():
        print('Please try again,and you must enter a number!')
        continue
    else:
        user = int(user)
        if user > age:
            print('Try smaller!')
        elif user < age:
            print('Try bigger!')
        else:
            print('You got it!')
            break
    count += 1

三、英语单词

必  须  背  诵  出  来  !

1、Programming

['proɡræmɪŋ]    n. 编程

2、Programming  language

['proɡræmɪŋ]   ['læŋɡwɪdʒ]   n.编程语言

3、high-level language

 

[,haɪ'lɛvl]  ['læŋɡwɪdʒ]   n.高级语言

4、machine language

[mə'ʃin]  ['læŋɡwɪdʒ]   n.机器语言

5、assembly language

 [ə'sɛmbli] ['læŋɡwɪdʒ]   n.汇编语言

 

6、variable

 ['vɛrɪəbl]   n. 变量 

 

7、memory

['mɛməri]   n.内存

 

8、binary

['baɪnəri]   n.二进制

 

9、decimalism

['desiməlizəm]    n.十进制

 

10、octal 

['ɑktl]    adj.八进制的

 

11、hexadecimal

[,hɛksə'dɛsɪml]    n.十六进制

 

12、file

 [faɪl]    n.文件

 

13、directory

[dəˈrɛktəri; (also) daɪˈrɛktəri]   n.目录

 

14、input

 ['ɪn'pʊt]    vt.输入

原文地址:https://www.cnblogs.com/fyknight/p/8007463.html