Function Arguments

A function can have more than one argument.

Keyword Arguments

Passing values by their names.

Code

1

2

3

4

5

6

def greet(arg_1, arg_2):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(arg_1=greeting,arg_2=name)

PYTHON

Input

Good Morning

Ram

Output

Good Morning Ram

Possible Mistakes - Keyword Arguments

Code

1

2

3

4

5

6

def greet(arg_1, arg_2):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(arg_2=name)

PYTHON

Input

Good Morning

Ram

Output

TypeError: greet() missing 1 required positional argument: 'arg_1'

Positional Arguments

Values can be passed without using argument names.

• These values get assigned according to their position.
• Order of the arguments matters here.

Code

1

2

3

4

5

6

def greet(arg_1, arg_2):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(greeting,name)

PYTHON

Input

Good Morning

Ram

Output

Good Morning Ram

Possible Mistakes - Positional Arguments

Mistake - 1

Code

1

2

3

4

5

6

def greet(arg_1, arg_2):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(greeting)

PYTHON

Input

Good Morning

Ram

Output

TypeError: greet() missing 1 required positional argument: 'arg_2'

Mistake - 2

Code

1

2

3

4

5

6

def greet(arg_1, arg_2):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet()

PYTHON

Input

Good Morning

Ram

Output

TypeError: greet() missing 2 required positional arguments

Default Values

Example - 1

Code

1

2

3

4

5

6

def greet(arg_1="Hi", arg_2="Ram"):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet()

PYTHON

Input

Hello

Teja

Output

Hi Ram

Example - 2

Code

1

2

3

4

5

6

def greet(arg_1="Hi", arg_2="Ram"):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(greeting)

PYTHON

Input

Hello

Teja

Output

Hello Ram

Example - 3

Code

1

2

3

4

5

6

def greet(arg_1="Hi", arg_2="Ram"):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(name)

PYTHON

Input

Hello

Teja

Output

Teja Ram

Example - 4

Code

1

2

3

4

5

6

def greet(arg_1="Hi", arg_2="Ram"):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(arg_2=name)

PYTHON

Input

Hello

Teja

Output

Hi Teja

Example - 5

Code

1

2

3

4

5

6

def greet(arg_1="Hi", arg_2):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(arg_2=name)

PYTHON

Input

Hello

Teja

Output

SyntaxError:non-default argument follows default argument

Non-default arguments cannot follow default arguments.

Example - 6

Code

1

2

3

4

5

6

def greet(arg_2, arg_1="Hi"):

print(arg_1 + " " + arg_2)

greeting = input()

name = input()

greet(arg_2=name)

PYTHON

Input

Hello

Teja

Output

Hi Teja

Passing Immutable Objects

Code

1

2

3

4

5

6

def increment(a):

a += 1

a = int(input())

increment(a)

print(a)

PYTHON

Input

5

Output

5

Even though variable names are same, they are referring to two different objects. Changing the value of the variable inside the function will not affect the variable outside.