Basics of Python

• Python was created by Guido van Rossum in 1991 as a general-purpose programming language.

• It is interpreted and interactive language. 

• Python is an open-source language under a general public license (GPL). 

• It supports both object-oriented and structured styles of programming.

Features:

• Cross-platform compatible: Python code can be executed on all platforms like Windows, Unix, Linux, and others.

• Open-source language.

• Supports both structured and object-oriented styles of programming.

• wide range of libraries.

• Provides interface required to connect all major databases like MySQL, Oracle, and Others 

Knowledge of the below basic concepts is a must before proceeding with the coding.

• Identifiers 

• Keywords

• variables

• datatypes

• Input, output statements

• Operators

• Comments

1) Identifiers:

• Identifiers are used to identify any variable, function, class, module, and object in python by using a name which is called an Identifier.

• Identifiers are case-sensitive.

• It can start with an uppercase or lowercase character or an underscore (_) followed by n number of underscores, letters, and digits.

      Example:  Number_1 = 50

                           Here Number_1 is an identifier

 

2) Keywords:

• Keywords are reserved words in python.

• These can't be used as an identifier to name a variable or function.

• Some commonly used keywords are given below
• if, elif, else, for, where, break, pass, continue, input

3) Variables:

• Variables are used to hold the data which are like a container.

• The value which the variable holds may not be the same throughout the program, it may change depending on the program logic.

• Syntax: Variable_name = value

      Example: Number_1 = 50

 

       In the above example, Number_1 is a container(variable) that holds the value 50. 

 

4) Datatypes:

• Every data belongs to some types. Commonly used data types are listed below

Category	Datatype	Example
Numeric	int	450
	long	32321343535675687
Numeric with a decimal point	float	345.67
	double	12453.5679873453
Alphanumeric	char	A
	string	tutorials
Boolean	boolean	True, False

     1) Dynamical language - Python:

        Example: Number_1 = 50

• In the above example, we didn't mention the data type at the time of declaring a variable but the python decides automatically based on the value which is assigned to it. This is called dynamic typing.

• Examples:

• Number_1 = 50  ---> Integer data type

• Number_1 = 'ÁBC'  ---> String data type 

• Try this CODE:

5.1) Input statement:

• input() is a built-in function that is used to read input from the user using a standard input device (i.e., keyboard)

• It always returns string data irrespective of what it receives from the user.

• Syntax: Variable_name = input('Interactive Statement')

• Example:
• input_num = input("Enter the number:")

5.2) Output statement:

• print() is a built-in function which is used to print the output on a standard output device (i.e., monitor)

• Syntax: print(Variable_name)

• Examples:

• print(Number_1)

• print("Hello")

6) Operators:

• Operators are the symbols used to perform some operations on the program.

• The most commonly used operators are listed below

Category	Operators
Arithmetic Operators		+,-,*,/, %,//
Relational Operators		==,!=,>,<,>=,<=
Assignment Operators		=,+=,-=,*=,/=,%=
Logical Operators		and, or, not

7) Comments:

• These are the lines that are skipped during the execution of the program.

• There are two types of comments in python.
• Single line comment: starts with the # symbol and extends till the end of the line.

• Multi-line comment: starts with '' / ''' ends with ''/'''.

• Mainly used for document purpose

• Example:

• Single line comment: #program to demonstrate the basics of python

• Multi-line comment: ''''used for Demonstrating comment.''''

Let's see the basic concepts in detail in the next tutorial.