After lunch, watch TV, new knowledge ---- function under review. I believe that many small partners in learning python, learn function there will be some people gave up, from trying to give up (the content is too true)
Well I hope I can have a lot of fans, hhh ....
function:
What is the function? What role is it?
Function is to make us lazy, yes, that is so simple and crude explanation. . .
Role in it? Our function is defined, the code needs to be called repeatedly on the inside, can be used repeatedly.
Description professional point is: function code for a package, the package code, if you do not call, they will not be executed.
We see a small case:
For example, see the boys called his brother hello, hello see the girl called her sister. For example, there are four individuals, two boys, two girls.
. 1 name_sex_1 = ( ' black ' , ' M ' ) 2 name_sex_2 = ( ' small army ' , ' M ' ) . 3 name_sex_3 = ( ' red ' , ' F ' ) . 4 name_sex_4 = ( ' xiaofang ' , ' F ' ) . 5 . 6 name, Sex = name_sex_1 . 7 IF Sex == ' M ' : . 8 Print( ' % S brother Hello ' % name) . 9 name, Sex = name_sex_2 10 IF Sex == ' M ' : . 11 Print ( ' % S brother Hello ' % name) 12 is name, Sex = name_sex_3 13 is IF Sex == ' F ' : 14 Print ( ' % S sister hello " % name) 15 name, Sex = name_sex_4 16 IF Sex == ' F ': . 17 Print ( ' % S sister Hello ' % name)
With a function to change the next case the above: we will find the above?
1 name_sex_1 = ('小黑','男') 2 name_sex_2 = ('小军','男') 3 name_sex_3 = ('小红','女') 4 name_sex_4 = ('小芳','女') 5 6 def name_sex(name,sex): #定义函数开的头用def关键字，后面紧跟自定义的函数名称，还有括号，以及：冒号结尾 7 if sex == '男': 8 print('%s 哥哥你好' % name) 9 elif sex == '女': 10 print('%s 姐姐你好' % name) 11 12 name,sex = name_sex_1 13 name_sex(name,sex) #调用我们定义的name_sex函数 14 15 name,sex = name_sex_2 16 name_sex(name,sex) #继续调用我们的函数
17 18 name,sex = name_sex_3
19 name_sex(name,sex) #依然调用我们定义的函数，这样代码可读性很强，很有规律
20 21 name,sex = name_sex_4 22 name_sex(name,sex) #还是调用我们的函数，如果需要调用多次，就会很省事。
接下来，我们看下函数的定义，再来认识下函数：
刚才的案例中，我们看到函数的定义需要用def关键字申明，这是一个函数，后面紧跟要定义的函数的名字，案例中的name_sex就是定义的函数名。
然后注意，括号后面一定要用：冒号结尾。括号里面可以放函数的参数,如果参数有多个就用【，】号来分开，比如案例中有两个参数在括号中。
1 def name_sex(name,sex):
我们再看下，函数定义完成后，他下面的函数体，需要和我们之前说的缩进一样：
1 def name_sex(name,sex): #定义函数开的头用def关键字，后面紧跟自定义的函数名称 2 if sex == '男': #以下都是函数体 3 print('%s 哥哥你好' % name) 4 elif sex == '女': 5 print('%s 姐姐你好' % name)
那么函数是怎么调用的呢?
调用函数是这样的：我们看到name_sex(name，sex) 这就是在调用我们定义的name_sex函数
1 name,sex = name_sex_2 2 name_sex(name,sex) #调用定义的name_sex函数 ,同时传入两个参数name和sex
总结：
1、怎么定义一个函数大家一定看懂了吧
2、函数的基本调用方法相信也明白了吧
3、函数的作用相信也有了大概的了解
明天开始细化函数的参数以及函数的返回~~晚安，如果对你有帮助，请关注我，如果你有不懂的请评论，看到会回复的，谢谢各位~