function (Python)

What is a function?

　　A function of a computer is a fixed program segment, or a subroutine. It can realize fixed operation functions and also has an entry and an exit. The so-called entry is the function. , we can use this entry to substitute the parameter values ​​of the function into the subprogram for computer processing; the so-called exit refers to the function value of the function, which is brought back to the calling program after the computer obtains it.

Use the features of functions: reduce code duplication, program extensibility, and easy maintenance.

Syntax Definition:

1  # @Software: PyCharm 
2  def say(): #Define function 
3      print ( ' hello world ' )
 4  
5 say() #Call function say 
6  
7  
8  
9  hello world
 10  
11 Process finished with exit code 0

View Code

 

# @Software: PyCharm
a,b = 5,2
def calc(x,y):
    res = x**y
    return  res
c = calc(a,b)
print(c)




25

Process finished with exit code 0

Parameters of the function:

Formal parameter: A variable is allocated a memory unit only when it is called, and the memory unit is released when the call ends, that is, it is only valid inside the function.

Argument: must have a definite value, pass the value to the formal parameter.

# @Software: PyCharm 
a,b = 5,2 # a,b actual parameters 
def calc (x,y): # x,y are formal parameters 
    res = x** y
     return   res
c = calc(a,b) #The actual parameter is passed to the formal parameter 
print (c)




25

Process finished with exit code 0

View Code