Parameters of the Python function

#CODING=GBK#parameters of the Python function: including required parameters, default parameters, variable parameters, keyword parameters#1 Required parameters, that is, each time you must select the parameters to be entereddefABS1 (num):#Calculate Absolute Value    ifisinstance (Num,[int,float]):returnABS (num)Else :        RaiseTypeError ("num is isn't the right type") A= ABS (1)Print(a)
#2 default parameter, that is, the system default value is used every time if you do not enterdefSqrt_n (x,n=2):#computes the n-th-squareS=1 whileN>0:s=s*x N=n-1returnsPrint(Sqrt_n (5))Print(Sqrt_n (5,3))#When the default parameter is high, you can call it again to specify the value of a parameter.defStudent_enroll (name,age,city="Beijing", gender='male'):    returnName,age,city,genderstudent1= Student_enroll ("Jim", 18) Student2= Student_enroll ("Obama", 18,gender="female")Print("St1 is:", Student1,'\nst2 is:', Student2)
#3 variable parameters, the number of arguments passed in is variable, they are called automatically assembled as a tuple example descriptiondefSum2 (*numbers):#calculate several numbers andSum2=0 forIinchnumbers:sum2=sum2+Ireturnsum2a= (1,5,2,6,2)#the use of list here is equally valid, the same wayPrint(Sum2 (*a))#A tuple is entered here, so the front of a plus * indicates a variable parameter, which can actually be writtenPrint(Sum2 (1,5,2,6,2))#orPrint(Sum2 (a[0],a[1],a[2],a[3],a[4]))
#4 keyword parameter, allow to pass in 0 or any parameter with parameter name, these keyword parameters are automatically assembled into a dictdefMatriculate (NAME,AGE,**KW):#the KW here is an abbreviation for keyword, and can also be substituted with other characters    return(name,age,kw) S1= Matriculate ("Tom", 18) S2= Matriculate ("Jack", 18,city ='Beijing', gender ='male')Print('S1 is:', S1,'\ n','S2 is:', S2)#You can also define the keyword parameters in advance (use SIM instead), and then directly use thesim={' City':'Beijing','Job':'Teacher','Gender':'male'}S3= Matriculate ('Hu', 18,**SIM)Print(S3)
#examples on the web#The most amazing thing is that through a tuple and dict, you can also call the function:defFunc (A, B, c=0, *args, * *kw):Print('A ='A'B ='B'C ='C'args =', args,'kw =', kw) args= (1, 2, 3, 4) kw= {'x': 99}func (*args, * *kw)#so, for any function, it can be called in the form of Func (*args, **kw)

#Note" "The default parameters must be used with immutable objects, such as L[]=none, otherwise the run will have a logical error *args is a mutable parameter, args receives a tuple () **kw is the keyword parameter, receives a dict{} using *args and * * KW is a Python idiom, but it can also be used with other parameter names, but it's best to use idioms" "#part of the reference from the network, hereby declares

Parameters of the Python function