[Python知识库]python循环、函数

def greet_user(username):
    print("侬好呀,"+username.title()+"!")
greet_user('alway')

#输出
侬好呀,Alway!


def favorite_book(title,author):#author="Alway"第二个形参指定默认值，如果
    #提供了实参就会忽略这个默认值
 #   print("One of my favorite book is "+title+".")
  #  print("It's writen by "+author+"")

#favorite_book(title="Enjoy",author="Frank")#关键字实参，顺序无关紧要
#favorite_book("Run","Andy")#位置实参

    full_mes=title+" is writen by "+author
    return full_mes#返回值
#调用返回值的函数时，需要提供一个变量，用于存储返回的值full_mes1
full_mes1=favorite_book("Alice in Wonderland","Bob")
print(full_mes1)

#输出
Alice in Wonderland is writen by Bob


def car(name,year,person): 
    car_mes=person +" have " + name +" for "+ year +" years"
    return car_mes
while True:
    print("\nWhat's your car's name")
    print("(caution:enter 'q' at any time to quit )")
    in_name=input("your name:")
    if in_name=='q':
        break
    in_year=input("year is:")
    if in_year=='q':
        break
    in_person=input("person:")
    if in_person=='q':
        break
    full_mes=car(in_name,in_year,in_person)
    print("hey,"+full_mes+"!")
#输出
What's your car's name
(caution:enter 'q' at any time to quit )
your name: Toyota
year is: 3
person: Alway
hey,Alway have Toyota for 3 years!

What's your car's name
(caution:enter 'q' at any time to quit )
your name: q

循环：

#% 求模运算
num=input("please input a number:")
num_int=int(num)  #字符串无法与整数比较，应该转换为数值表示
if num_int%2==0:
    print("it is a even")
print("it is a odd")

#输出 略

prompt="\nTell me your name,and I will repeat it back to you :"
prompt+="\nEnter 'quit' to end it."
#这个示例演示了一种创建多行字符串的方式。
#第1行将消息的前半部分存储在变量prompt中；
#在第2行中，运算符+=在存储在prompt中的字符串末尾附加一个字符串。
message=""#创建一个变量用于存储用户的值       
#Python首次执行while语句时，需要将message的值与'quit'进行比较，但此时用户还没有输入。
#如果没有可供比较的东西，Python将无法继续运行程序。为解决这个问题，我们必须给变量message指定一个初始值。
#虽然这个初始值只是一个空字符串，但符合要求，让Python能够执行while循环所需的比较。
while message!="quit":
    message=input(prompt)
    if message !='quit':
        print(message)

#输出
Tell me your name,and I will repeat it back to you :
Enter 'quit' to end it. alway
alway
Tell me your name,and I will repeat it back to you :
Enter 'quit' to end it. 
Tell me your name,and I will repeat it back to you :
Enter 'quit' to end it. quit


——————————————————————————————————————————————————————————————————
prompt="\nTell me your name,and I will repeat it back to you :"
prompt+="\nEnter 'quit' to end it."
active=True
while active:
    message=input(prompt)
    if message=='quit':
        active=False
        #break     #也可以这样使用break退出循环
    else:
        print(message)



cur_num=0
while cur_num<=100:
    cur_num+=1
    if cur_num%3!=0:
        continue
    else:
        print(cur_num)
#如果程序陷入无限循环，可按Ctrl+C，也可关闭显示程序输出的终端窗口

#输出：打印0~100能被3整除的整数。