Arguments in Python

Arguments in Python

Function with Position arguments(Non-Default arguments)

function with parameterized variable, where value is not assigned to any parameterized variable

 # different ways of calling function with non-default values
 display("Techno Xpress", 28)
 display(28, "Techno Xpress")
 display(age=28, name="Techno Xpresss")

 #output
 name:  Techno Xpress   age:  28
 name:  28  age:  Techno Xpress
 name:  Techno Xpresss  age:  28

• whatever values we will pass, it will take as position as in call 1 and call 2 in above example

• we can also pass value by directly assigning it to parameterized variable while calling the function. 

Function with arguments as default values(Default arguments)

function with parameterized variable, where value is assigned to any parameterized variable while defining

 #program to understand Default arguments
 def display(name = None , age = 28 , marks = 80.72) :
     print("\nname: ", name, "\tage: ", age, "\tMarks: ", marks)

 display()
 display("Techno Xpress", 28, 80.72)
 display(25, "Techno Xpress")
 display(marks = 90, age= 26, name= "Er M S Dandyan")


 #output
 name:  None    age:  28   Marks:  80.72

 name:  Techno Xpress   age:  28   Marks:  80.72

 name:  25  age:  Techno Xpress    Marks:  80.72

 name:  Er M S Dandyan  age:  26   Marks:  90

• we can pass values in many ways
• but remember until we are not assigning value to any parameterized variable while calling the function, values will be assigned based on positions
• if we are not passing values, it will take default value

Function with Default and Non-Default argument

passing Default and Non-default arguments

 #program to understand Default + Non-Default arguments
 def display(age = 28 , marks = 80.72, name) :
     print("\nname: ", name, "\tage: ", age, "\tMarks: ", marks)


 display("Techno Xpress")


 #output
   File "C:/Self_Practice_Er_M_S_Dandyan/Python/Pycharm/xml/main.py", line 50
     def display(age = 28 , marks = 80.72, name) :
                ^
 SyntaxError: non-default argument follows default argument

Python has a rule to use Default and Non-Default parameter at same time.

• Non-default argument follows default argument

Correct Way

 #program to understand Default + Non-Default arguments
 def display(name, age = 28 , marks = 80.72) :
     print("\nname: ", name, "\tage: ", age, "\tMarks: ", marks)


 display("Techno Xpress")
 display("Techno Xpress", 28 , 80.72)
 display(28, "Techno Xpress")


 #output
 name:  Techno Xpress   age:  28   Marks:  80.72

 name:  Techno Xpress   age:  28   Marks:  80.72

 name:  28  age:  Techno Xpress    Marks:  80.72

Limitation:

 #program to understand Default + Non-Default arguments
 def display(name, age = 28 , marks = 80.72) :
     print("\nname: ", name, "\tage: ", age, "\tMarks: ", marks)

 display("Techno Xpress", name ="Er M S Dandyan")

 #output
 Traceback (most recent call last):
   File "C:/Self_Practice_Er_M_S_Dandyan/Python/Pycharm/xml/main.py", line 5, in <module>
     display("Techno Xpress", name ="Er M S Dandyan")
 TypeError: display() got multiple values for argument 'name'

by default the first position is for Non-Default argument, and we can not pass multiple values to same variable