Python programming #2;Overview of Builtin functions with few examples

Hello everyone! Welcome to our Blog HIGH TECHDROID and this is Lavanya. Today we are going to see about built-in functions. 

Introduction:

                    First, we'll have a short demo on what are built-in functions. Let me assign a=’good’. If I want to print it, I give as print(a). Thus, I need a function called print() to print the value of a. This is called as built-in functions. Like this, there are many built-in functions supported in Python like input(), min(), max(), len(), replace() and so on. Let’s have a look on it now. 

                Here, I have described few built-in functions along with their functionalities. First is      import, that is, __import__. In C, we use header files like #include<stdio.h> whereas we use this import to import modules in Python. abs() is to find the absolute value of a variable or a number. Next is, print() to print the value of a variable or display the output. Input() is to get input from user. When a set of attributes or parameters are given, max()/min() can be used to ind the maximum and minimum of all respectively. Next, int(), float() and str() are used for typecasting. Converting from one datatype to another is called as typecasting and above are used for it. Next is id(). Every object has an identity in its lifetime. If u want to know the identity of an object, it can be found by giving the object as the parameter to id(). In C, we use strlen(). Here, we use len() to find the length of the variable. In Python, we don’t declare the variable with its datatype instead we declare it with its value. Hence, you can know the datatype of any variable by giving it as parameter. Next is pow(a,b). If it is 2^3 or 5^4 it can be computed easily whereas it is 50^100, it is tedious. Hence, we use this function. If it has 3 parameters, then a^b is computed first followed by computation of modulo c. Next is sum() which is usually used in excel sheets for computation for calculating the sum of many variables. Round()… the value of pi(22/7) goes on like 3.142…which can be rounded off to certain digits using round(). Next is eval() which evaluates large arithmetic expression using BODMAS without getting confused. 

              Not only these functions, also there are many built-in functions present which helps to    denote the errors that occur. First is ImportError which is displayed when the required modules are not imported. SyntaxError occurs when there is an error in syntax of code. We know that 5/0 is equal to infinity which cannot be determined. In such cases ZeroDivisionError is displayed to denote it. TypeError occurs in case of mistakes made regarding datatype. When you request for read/write command to a file and when the corresponding file is not found, there raises the FileNotFoundError. If you tend to make any mistakes in input or output, that is, giving inappropriate input, then IOError is displayed. RunTimeError occurs to denote the errors that occur in run-time of the program. 

Available builtin functions in python:

   Let’s take a look at few examples now. Before that, to know all the built-in functions available in Python, there is a command to help us. That is , dir(__builtins__). On pressing Enter after this command, all the available built-in functions regarding Error, Integer and String are displayed. Okay, there is a command to find all those available built-in functions but to know each of their functionalities, there is a function called help(). For example, help(max) where max is a built-in unction lets you know that max() collects a list of arguments and returns the biggest of them.

Examples:

                   For example, I give few parameters as max(3754,83,5423,58785) out of which the          highest one ie., 58785 is returned. Not only this, typecasting can be done as, I assign a=5.325 and on giving int(a), the integer part ie.,5 alone is returned. Many manipulations can also be done in string using the built-in functions. I assign a=’good’. If I want to replace the letter ‘g’ with ‘f’ and convert it to ‘food’, it can be done as a.replace(‘g’,’f’). Thus, replace() can be used to replace a letter or sub-string in a word. If I give len(‘food’), it returns 4 which is the length of the string. Also, there is a function called swapcase() which helps to return the string in opposite case. ie., upper to lower or lower to upper. I assign a=’good’ and on giving a.swapcase(), I’ll get the output as ‘GOOD’ with lowercase swapped to uppercase. 

The overall Builtin's of python is given below:

Python abs()	returns absolute value of a number
Python all()	returns true when all elements in iterable is true
Python any()	Checks if any Element of an Iterable is True
Python ascii()	Returns String Containing Printable Representation
Python bin()	converts integer to binary string
Python bool()	Converts a Value to Boolean
Python bytearray()	returns array of given byte size
Python bytes()	returns immutable bytes object
Python callable()	Checks if the Object is Callable
Python chr()	Returns a Character (a string) from an Integer
Python classmethod()	returns class method for given function
Python compile()	Returns a Python code object
Python complex()	Creates a Complex Number
Python delattr()	Deletes Attribute From the Object
Python dict()	Creates a Dictionary
Python dir()	Tries to Return Attributes of Object
Python divmod()	Returns a Tuple of Quotient and Remainder
Python enumerate()	Returns an Enumerate Object
Python eval()	Runs Python Code Within Program
Python exec()	Executes Dynamically Created Program
Python filter()	constructs iterator from elements which are true
Python float()	returns floating point number from number, string
Python format()	returns formatted representation of a value
Python frozenset()	returns immutable frozenset object
Python getattr()	returns value of named attribute of an object
Python globals()	returns dictionary of current global symbol table
Python hasattr()	returns whether object has named attribute
Python hash()	returns hash value of an object
Python help()	Invokes the built-in Help System
Python hex()	Converts to Integer to Hexadecimal
Python id()	Returns Identify of an Object
Python input()	reads and returns a line of string
Python int()	returns integer from a number or string
Python isinstance()	Checks if a Object is an Instance of Class
Python issubclass()	Checks if a Object is Subclass of a Class
Python iter()	returns iterator for an object
Python len()	Returns Length of an Object
Python list()	creates list in Python
Python locals()	Returns dictionary of a current local symbol table
Python map()	Applies Function and Returns a List
Python max()	returns largest element
Python memoryview()	returns memory view of an argument
Python min()	returns smallest element
Python next()	Retrieves Next Element from Iterator
Python object()	Creates a Featureless Object
Python oct()	converts integer to octal
Python open()	Returns a File object
Python ord()	returns Unicode code point for Unicode character
Python pow()	returns x to the power of y
Python print()	Prints the Given Object
Python property()	returns a property attribute
Python range()	return sequence of integers between start and stop
Python repr()	returns printable representation of an object
Python reversed()	returns reversed iterator of a sequence
Python round()	rounds a floating point number to ndigits places.
Python set()	returns a Python set
Python setattr()	sets value of an attribute of object
Python slice()	creates a slice object specified by range()
Python sorted()	returns sorted list from a given iterable
Python staticmethod()	creates static method from a function
Python str()	returns informal representation of an object
Python sum()	Add items of an Iterable
Python super()	Allow you to Refer Parent Class by super
Python tuple()	Creates a Tuple
Python type()	Returns Type of an Object
Python vars()	Returns __dict__ attribute of a class
Python zip()	Returns an Iterator of Tuples
Python __import__()	Advanced Function Called by import

Download Builtin() file: