Name: Prithiksha.E
Sub Code: GE3151
Class: B.Tech-1st Year
FUNCTIONS IN PYTHON
Functions
A function is a block of code which only runs when it is called.
You can pass data, known as parameters, into a function.
A function can return data as a result.
Creating a Function
In Python a function is defined using the def keyword:
Example:
def my_function():
print("Hello from a function")
Calling a Function
To call a function, use the function name followed by parenthesis:
Example:
def my_function():
print("Hello from a function")
my_function()
Arguments
Information can be passed into functions as arguments.
Arguments are specified after the function name, inside the parentheses. You can add as
many arguments as you want, just separate them with a comma.
The following example has a function with one argument (fname). When the function is
called, we pass along a first name, which is used inside the function to print the full name:
Example:
def my_function(fname):
print(fname + " Refsnes")
my_function("Emil")
my_function("Tobias")
my_function("Linus")
Arguments are often shortened to args in Python documentations.
, Parameters or Arguments?
The terms parameter and argument can be used for the same thing: information that are
passed into a function.
From a function's perspective:
A parameter is the variable listed inside the parentheses in the function definition.
An argument is the value that is sent to the function when it is called.
Number of Arguments
By default, a function must be called with the correct number of arguments. Meaning that if
your function expects 2 arguments, you have to call the function with 2 arguments, not more,
and not less.
Example:
This function expects 2 arguments, and gets 2 arguments:
def my_function(fname, lname):
print(fname + " " + lname)
my_function("Emil", "Refsnes")
If you try to call the function with 1 or 3 arguments, you will get an error:
Example:
This function expects 2 arguments, but gets only 1:
def my_function(fname, lname):
print(fname + " " + lname)
my_function("Emil")
Arbitrary Arguments, *args
If you do not know how many arguments that will be passed into your function, add
a * before the parameter name in the function definition.
This way the function will receive a tuple of arguments, and can access the items
accordingly:
Example:
If the number of arguments is unknown, add a * before the parameter name:
Sub Code: GE3151
Class: B.Tech-1st Year
FUNCTIONS IN PYTHON
Functions
A function is a block of code which only runs when it is called.
You can pass data, known as parameters, into a function.
A function can return data as a result.
Creating a Function
In Python a function is defined using the def keyword:
Example:
def my_function():
print("Hello from a function")
Calling a Function
To call a function, use the function name followed by parenthesis:
Example:
def my_function():
print("Hello from a function")
my_function()
Arguments
Information can be passed into functions as arguments.
Arguments are specified after the function name, inside the parentheses. You can add as
many arguments as you want, just separate them with a comma.
The following example has a function with one argument (fname). When the function is
called, we pass along a first name, which is used inside the function to print the full name:
Example:
def my_function(fname):
print(fname + " Refsnes")
my_function("Emil")
my_function("Tobias")
my_function("Linus")
Arguments are often shortened to args in Python documentations.
, Parameters or Arguments?
The terms parameter and argument can be used for the same thing: information that are
passed into a function.
From a function's perspective:
A parameter is the variable listed inside the parentheses in the function definition.
An argument is the value that is sent to the function when it is called.
Number of Arguments
By default, a function must be called with the correct number of arguments. Meaning that if
your function expects 2 arguments, you have to call the function with 2 arguments, not more,
and not less.
Example:
This function expects 2 arguments, and gets 2 arguments:
def my_function(fname, lname):
print(fname + " " + lname)
my_function("Emil", "Refsnes")
If you try to call the function with 1 or 3 arguments, you will get an error:
Example:
This function expects 2 arguments, but gets only 1:
def my_function(fname, lname):
print(fname + " " + lname)
my_function("Emil")
Arbitrary Arguments, *args
If you do not know how many arguments that will be passed into your function, add
a * before the parameter name in the function definition.
This way the function will receive a tuple of arguments, and can access the items
accordingly:
Example:
If the number of arguments is unknown, add a * before the parameter name:
