python学习-7 条件语句 while循环 + 练习题

1.死循环

while 1 == 1:
     print('ok')

结果是一直循环

2.循环

count  = 0
while count < 10:
     print(count)
     count = count +1
print(error)

3.练习题

~ 使用while循环输出1 2 3 4 5 6   8 9 10

count = 1
 
while count <= 10 :                    # 或者count < 11
    if count == 7:
        print( )                       # 也可以添加pass，什么也不执行
    else:
       print(count)
    count = count + 1

执行结果：

1
2
3
4
5
6
 
8
9
10
 
Process finished with exit code 0

~ 求1-100的所有数的和

a = 1
b = 0
while a < 101:
    b = b + a
    a = a + 1
print(b)

输出结果：

5050
 
Process finished with exit code 0

~求1-100内所有的奇数

n = 1
while n < 101:
    js = n % 2
    if js == 0:
        print( )
    else:
        print(n)
    n = n + 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

~ 求1-100内所有的偶数

a = 1
while a < 101:
    b = a % 2
    if b == 0:
        print(a)
    else:
        pass
    a = a + 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
 
Process finished with exit code 0