Python - Introduction , history

    • Python is an object oriented , high level , powerful structured and scripting language developed by Guido Van Rossum in 1989.
    • The first version of python was released in 1991 which is used for creating anything from desktop software to web applications and frameworks also .
    • The python program is always save with extension .py 
    • We use python IDLE for creating and executing programs in python. 
    • Python is called as scripting language that is python is interpreted at run time more than compile time .
    • Text manipulation , processing and searching are always faster in python than any other platforms .
    • Python has many implementations like jpython , cpython , Brypython , Ipython
    •  There are two major Python versions: Python 2 and Python 3. Both are quite different.
    • To represent a statement in Python, newline (enter) is used. The use of semicolo: statement is optional (unlike languages like C/C++, PHP). In fact, it's recommended at the end of the statement in Python. Instead of curly braces ().
    • Indentations are used to represent a block.

Applications of Python :

    • Web applications
    • Software development 
    • Business applications
    • Console based applications
    • GUI based desktop applications
    • Scientific and numeric applications
    • 3D CAD applications 
    • Enterprise applications
    • Education

What is scripting language ?

    • A scripting language is a language that is interpreted at run time, rather than compile ,  executable
    • Scripting languages allow us to write simple script for GUI quickly, and run compilation. They also have good support for launching processes and controlling files, etc.
    • Scripting languages are becoming more popular due to the emergence of web-base market for producing dynamic web content is now expanding extremely rapid scripting languages have been developed to allow users with little or no program develop interactive web pages with minimum effort.
    • Text manipulation, text processing and searching are faster in Scripting Languages.
    •  Python offers the clean and simple syntax of the popular scientific computing environment.
    • The language is very powerful and there are lots of tools for gluing your favorite  visualization, and data analysis programs the way you want. In other words, Python build your own Matlab-like scientific computing environment.
    • The task such as shuffling data in and out of different tools, converting one data extracting numerical data from a text, and administering numerical experiment number of data files and directories are much faster to accomplish in a Python C++, C#, or Java.
    • Python is interpreted scripting language, not be compiled. Fast code run loops w language make it faster to develop than a complied language. 

Scripting techniques for computing in python :

    • Code re-use : Python provides the benefits of object-oriented & generic programming language and which have syntax more easy than java and c++ .
    • High-level tools for simplifying Mixed-Language Integration : Python is an editor window and simply jump to another part to write number crunching or C++, often calling up your own libraries in those languages. With just program running a simple one-line command, the Python script works with the external.

Classification of Programming Languages : 


Computer programming languages are used to communicate instructions to a computer. They are based on certain syntactic and semantic rules, which define the meaning of each of the programming language constructs. Today, there are many of programming languages weed in the industry.

The Programming Languages are classified as follows:

1. Machine languages:  
    • It is the Lowest Level and named as First Generation of Programming Language .
    • Machine Level Language consist only two conditions i.e either true (1) or false (0) .
    • It is also know as binary language .
    • A computer system could understand only binary language i.e.  all the instruction feed into the computer system must be in the form of 0 or 1.
    • This types of machine level languages are very hard to learn for humans .
2. Assembly languages: 
    • Assembly language is a Middle Level and named as Second Generation Programming Language.
    • It uses symbols to describe field of instructions.
    • It contains the same instructions as Machine Level Language Instructions and the variables have specific name and called Commands. 
    • Every aspect of machine variable in program, assembly language uses one statement per machine instruction. It managed explicitly all instruction like register allocation, call, stack, timer, jump, loop etc.
    • To understand the Assembly language computer must require an Assembler which takes a part in between assembly language and computer system to convert the assembly instructions into the machine language. This assembler is software or a set of program which translates assemble programming Instruction into the machine language.
    • Example : STORE GROSS
3. High-level languages: 

    • High Level Languages are procedure-oriented languages and are machine independent. 
    • High level language is the upper level language and also known as third generation programming language. 
    • Programs written in high level language must require software or a set of program to translate that program into machine understandable. This software called compiler and/or interpreter. The main task of compiler and translator is that to take the source code of the program and convert that code into the machine understood code.
    • Example: FORTRAN, Pascal, C, C++, JAVA, ADA, COBOL, LISP, Prolog.

4. Visual Languages: 

    • Visual Programming Languages (VPL) allows users specify programs in a two-for more)-dimensional way, instead of as one-dimensional text strings, via graphic layouts of various types.
    • Example: Analytica Blockdy, Toontalk.

5. Scripting Languages: 

    • A Scripting Language is a programming language designed for integrating and communicating with other programming languages. These are generally extremely high-level and powerful.
    • Example: Javascript, Vascript, PHP, Perl, Python, Ruby, ASP and Td.

6. System Languages: 

    • A System Programming Language refers to a Programming Language used for system programming such languages are designed for writing system software.
    • Example: PL/L. D, Rust, Swift.

7. Domain-specific Languages: 

    • A Domain-specific Language (DSL) is a programming language that is developed to meet a specific need. These are used in highly special purpose areas only.
    • Example: Cascading Style Sheets (CSS), Ant and SQL.
8. Esoteric languages: 

    • An Esoteric Programming Language in a programming language designed as a test of the boundaries of computer programming language design, as a proof of concept, or as a joke. These are not really intended to be used, but are very interesting, funny, or educational in some way.
    • Example: Beatnik, Befunge, Piet, whitespace

9. Glue Language: 

    • Glue language refers to a Programming Language that is designed specifically to write and manage program and code, which connects together different software components. 
    • Glue language primarily enables creating glue code. 
    • It enables interconnecting, support and the integration of software programs and components created using different programming languages and platforms
    • Example: VBScript, Ruby, Python, Perl and PHP.