Functions and their use in Python

Function is an arrangement of a statement that execute like a data processing or computing.  Whenever you define a function you define the name of the function. You can call a function by its name, it is called a  function call.

Syntax

def functionname( parameters ):
   "function_docstring"
   function_suite
   return [expression]

The function takes an argument and returns  a result.The result is called aReturn value.

Built-in Functions

Python provides a number of built-in function which convert the values from one type to the other type such as maxand minfunction. It gives us the largest and smallest value in a list.The max function declares "largest character"  whereas the min function declare the"smallest character"in the string.

Syntax

max(iterable, *iterables[,key, default])
max(arg1, arg2, *args[, key])

Example:

max(2,3,4)

Output:

>>>max(2,3,4)
>>> 4

min(2,3,4)

Output:

>>>min(2,3,4)
>>> 2

Types of Conversion Functions

Integer Conversion:

The int function converts the any value of an integer.  We can convert integer number in many types  such as int to float, int to string etc. Some of the examples are:

int can convert floating-point value to integer, it doesn't round off or cuts the fractional part .

int(5.99999)
int(-4.9)

Output: 

>>>int(5.99999)
>>>5
>>>int(-4.9)
>>>-4

Float Conversion:

float convets the integer and string into floating point numbers.

float(89)

Output: 
>>>float(89)
>>>89.0

String Conversion:

str converts its arguments in a string

str(30)
str(4.909090)

Output: 
>>>str(30)
>>>'30'
>>>str(4.909090)
>>>'4.909090'

Math Functions

Python provides some of the usual mathematical functions in math module. Before using that module you have to import it.

import math

For creating  module object we use the word math. To get some information by printing the module object .The module object consists of the functions and variables defined to access one of the functions, you have to specify the name of the module and the name of the function, distinct by a dot . This format is called dot notation.

print(math)

>>><module 'math' (built-in)> 

ratio= signal_power / noise_power
decibels = 16 * math.log10(ratio)
radians = 0.6
height = math.sin(radians)

Some useful Math function are: