Functions are a group of statements which is used to perform a task.These tasks can repetitive , big task which is divided in smaller chunks of code. Syntax of the Function :
def function_name(parameters): code_body return_statement(s)
The above syntax can be broken into five parts mainly
'def' here is used as a keyword to start a function.
'function_name' is used for uniquely identifying the function with a proper name.
Parameter are nothing but the arguments which are passed inside the code_body to perform a certain task and is optional.
'code_body' block of codes telling the function what exactly to do .
'return _statement' is optional and is being used to return value of function.
For Example of Simple Function
def tell_me_yourname(name): print("Hi ! My name is "+ name)
This function will print a name which has been assigned by the user in the variable name. How to call a function ?
Calling the function is very easy and let you re-use the code.All you have to do is take the name of the function and use it appropriate parameters.
>> tell_me_yourname(Roy) Hi ! My name is Roy
Return Statement It 's one of the statement which is used return the value which has been passed by going back to starting point that is "def" followed by function_name. The idea here is to exit and re - run the code as per the convenience of the user.
def real_value(a,b): if a>0: return a else a<0: return -b print ((real_value(4,-9)) Output: 4 -9
Types of Functions 1.User Defined Functions
What we have just seen are "User Defined Functions" as user is directly in control how he wants execute the things. Built-In Functions are which performs certain tasks in python just calling out the names of function. For example dict() - creates dictionary in python, float()- returns floating point number from string/number etc.
I hope you are cleared with functions check out the code provide in the link for more information.