1 print("Hello world!")
1 if True: 2 print("ok!")
在python中多重条件判断同其他编程类似也是采用if-else,但不同之处在于多重循环中间部分的if-else写成elif即可,
1 _username = "Gunner" 2 _password = "ljq123" 3 username = input("username:") 4 password = input("password:") 5 if username == _username and password == _password : 6 print("Welcome user {name} login...".format(name=username)) 7 else : 8 print("Invalid username or password! ")
fromat()方法在第六点格式化输出会讲解
1 for i in range(1,10): 2 print("loop:",i)
1 for i in range(1,10): 2 for j in range(i,10): 3 print("%d * %d = %2d" % (i,j,i*j),end = " ") 4 print("")
1 for i in range(1,10): 2 for j in range(1,i+1): 3 print("%d * %d = %2d" % (i,j,i*j),end = " ") 4 print("")
两种代码存在略微不同,打印出来的乘法表,方向会发生改变!
1 count = 0 2 while count < 3: 3 print("keep on:",count) 4 count += 1 5 else: 6 print("Quit!")
1 for i in range(5): 2 print(‘-------------‘ , i ) 3 for j in range(5): 4 print(j) 5 if j > 1: 6 break 7 print("good!")
以上代码执行之后,是两个for循环,当第二个for循环中到了2 的时候break会让循环跳出,即3,4不会显示在第二个循环中,但是第一个for循环会显示0-4所有值
1 for i in range(5): 2 print("hehe...") 3 if i < 2: 4 print("loop:",i) 5 else: 6 continue
以上代码执行之后,第一层是for循环遍历输出,第二层是if判断,在0,1的时候,输出的值跟2,3,4输出的有区别,这就是continue的作用,使得程序跳出了if判断, 只进行for循环
1 name = input("name:") 2 age = int(input("age:")) 3 job = input("job:") 4 salary = int(input("salary:")) 5 6 info = ‘‘‘ 7 -------- info of %s -------- 8 Name:%s 9 Age:%s 10 Job:%s 11 Salary:%s 12 ‘‘‘%(name,name,age,job,salary) 13 14 print(info)
使用%s占位符,格式化输出,强调在输入代码的出,要将str强转为int类型,因为age还有salary都是int类型
1 name = input("name:") 2 age = int(input("age:")) 3 job = input("job:") 4 salary = int(input("salary:")) 5 6 info = ‘‘‘ 7 -------- info of {name} -------- 8 Name:{name} 9 Age:{age} 10 Job:{job} 11 Salary:{salary} 12 ‘‘‘.format(name = name, 13 age = age, 14 job = job, 15 salary = salary) 16 17 print(info)
使用format()方法格式化输出
1 name = input("name:") 2 age = int(input("age:")) 3 job = input("job:") 4 salary = int(input("salary:")) 5 6 info = ‘‘‘ 7 -------- info of {0} -------- 8 Name:{0} 9 Age:{1} 10 Job:{2} 11 Salary:{3} 12 ‘‘‘.format(name, age, job, salary) 13 14 print(info)
同样是format()方法输出,但是要对变量的顺序十分谅解,不建议这样使用,有一种用+链接的方式,更加繁琐,需要开辟更多的存储空间,所以这里不多做讲述
原文:https://www.cnblogs.com/lijianqing/p/9256684.html