1 #__author: hlc
2 #date: 2019/5/25
3
4 # for i in range(1,100,2) : #2为步长
5 # print("loop:",i)
6
7 # for i in range(100) :
8 # if i < 20 or i > 80 :
9 # print(i)
10 #
11 # _user = "abc"
12 # _passwd = "123"
13 #
14 # flag = False
15 # for i in range(3) :
16 # username = input("your usernaem>>>: ")
17 # password = input("your password>>>: ")
18 # if username == _user and password == _passwd :
19 # print("Welcome %s login ..." % _user)
20 # flag = True
21 # break #跳出 ，中断
22 # else:
23 # print("Invalid username or password !")
24 # if not flag :
25 # print("错误次数过多！。。。")
26 #
27 # C:\python37\python.exe D:/python-note/for_loop.py
28 # your usernaem>>>: sdaf
29 # your password>>>: asdf
30 # Invalid username or password !
31 # your usernaem>>>: abc
32 # your password>>>: 123
33 # Welcome abc login ...
34
35 # C:\python37\python.exe D:/python-note/for_loop.py
36 # your usernaem>>>: a
37 # your password>>>: a
38 # Invalid username or password !
39 # your usernaem>>>: a
40 # your password>>>: a
41 # Invalid username or password !
42 # your usernaem>>>: a
43 # your password>>>: a
44 # Invalid username or password !
45 # 错误次数过多！。。。
46
47 _user = "abc"
48 _passwd = "123"
49
50 for i in range(3) :
51 username = input("your usernaem>>>: ")
52 password = input("your password>>>: ")
53 if username == _user and password == _passwd :
54 print("Welcome %s login ..." % _user)
55 break #跳出 ，中断
56 else:
57 print("Invalid username or password !")
58 else:
59 print("错误次数过多！。。。")
60
61 # C:\python37\python.exe D:/python-note/for_loop.py
62 # your usernaem>>>: sdf
63 # your password>>>: sadf
64 # Invalid username or password !
65 # your usernaem>>>: asdf
66 # your password>>>: asdf
67 # Invalid username or password !
68 # your usernaem>>>: asdf
69 # your password>>>: asdf
70 # Invalid username or password !
71 # 错误次数过多！。。。
1 # continue 结束本次循环，继续下一次循环
2 # break 跳出当前整个的循环
3
4 exit_flag = False
5 for i in range(10):
6 if i < 5 :
7 continue
8 print(i)
9 for j in range(10) :
10 print("layer2: ",j)
11 if j == 6 :
12 exit_flag = True
13 break
14 if exit_flag :
15 break
