Types of Arguments

There are 4 types how we can pass arguments to functions in python

1) Default arguments
2) Required arguments
3) Keyword arguments
4) Variable number of arguments

Default arguments: Default values indicate that the function argument will take that value if no argument value is passed during function call. The default value is assigned by using assignment (=) operator. 

EX:

### Function definition
def display(name,age=23):
print(name,age)

### Function call
display(name=’jack’)
display(name=’tom’,age=32)
display(age=16,name=’jerry’)

o/p

jack 23
tom 32
jerry 16

Required arguments: Required arguments are the mandatory arguments of a function. These argument values must be passed in correct number and order during function call.

Ex:

### Function definition
def display(city,timezone):
print(city,timezone)

### Function call
display(‘hyderabad’,’GMT’)
display(timezone=’GMT’,city=’hyd’)
display(‘hyderabad’)

o/p:

hyderabad GMT
hyd GMT

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-18-bab62319b1b8> in <module>
      6 display('hydetabad','GMT')
      7 display(timezone='GMT',city='hyd')
----> 8 display('hyderabad')

TypeError: display() missing 1 required positional argument: 'timezone'

Keyword arguments: The keywords are mentioned during the function call along with their corresponding values. These keywords are mapped with the function arguments so the function can easily identify the corresponding values even if the order is not maintained during the function call.

Ex:

### Function definition
def display(country,capital):
print(country,capital)

### Function call
display(country=’india’,capital=’delhi’)
display(capital=’washington’,country=’usa’)
display(country=’china’)

o/p

india delhi
usa washington

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-21-9bcdc7846b7c> in <module>
      6 display(country='india',capital='delhi')
      7 display(capital='washington',country='usa')
----> 8 display(country='china')

TypeError: display() missing 1 required positional argument: 'capital'

Variable number of arguments: This is very useful when we do not know the exact number of arguments that will be passed to a function.

Ex:

### Function definition
def display(*languages):
for i in languages:
print(i)

### Function call
display(‘c’,’java’,’python’,’dotnet’,’cobal’)

o/p:

c
java
python
dotnet
cobal