Introduction to Programing & Python

Good morning Dear students.

 Welcome to the e-classroom of Computer Science. I am Mrs Geeta Sehgal, your Computer Sc teacher for this academic session. 🙏

You are expected to have with you 

• properly covered registers and 
• a pen 

to take down the important concepts discussed during this session.

Don’t forget, a neatly presented work is always more appreciated.
------------------------------------------------------------------------------------------------------

As most of you are without the textbook. Following is the image you would be expected to refer to. We will be using this image for a few sessions in the future as well.

                                                   

By the end of this session, you will be able to understand few important terms related to Programing Languages and an introduction to Programing Language ,Python.

---------------------------------------------------------------------------------------------------

 In the beginning, we have to familiarize ourselves with the following important  

terms:

1. Machine Language:-

•      often referred to as machine code , machine language or Low Level Language(LLL)
•  is a collection of binary digits or bits that the computer reads and interprets.
•  is the only language a computer is capable of understanding. So, it is said to be closer to the machines (so the term "LOWER LEVEL")

2. Programing Language:-

• is a type of written language that tells computers what to do in order to work. 
•  is used to make all the computer programs and computer software.
•  uses real words for some of the commands, so that the language is easier for a human to read.                         
• So, it is said to be closer to the user  and hence called High Level Language (HLL). (This explains the term "High Level", as the user finds himself at a higher level than the machine. )

So, with this clarity, we must understand that a 

• High Level Language must be converted to Machine Language so that the commands can be executed to give the desired result. 
• For this conversion of the program written in High Level Language to machine language is MANDATORY.
• For doing this one of the language translators, either a COMPILER or an INTERPRETER may be used.

KEY DIFFERENCES

• Compiler transforms code written in a high-level programming language into the machine code, at once, before program runs, whereas an Interpreter coverts each high-level program statement, one by one, into the machine code, during program run.
• Compiled code runs faster while interpreted code runs slower.
• Compiler displays all errors after compilation, on the other hand, the Interpreter displays errors of each line one by one.
• Compiler takes an entire program whereas the Interpreter takes a single line of code.

Python is 

·      Widely used

·      interpreted (converts the source code to machine code)

·      object oriented

·      High level programming language(Closer to the human beings)

·      created by Guido Van Rossum 

·      released on February 20,1991

·      easy to code but as powerful as the other programming languages.

·      Syntax is as understandable as plain English

·     Globally known applications such as YouTube, BitTorrent, DropBox, Netflix etc. use Python to achieve their functionality.

Let us look at some key features of Python:

1. Simple-

•  Written in simple English statements.
•  Therefore, it is easy to understand the syntax( way of writing) and develop programs.

2. Easy to learn- 

• uses very few keywords (set of special words which have a specific meaning).
• structure of program is very simple and easy to create. 

EXERCISE

Answer the following questions based on the above discussion:

1. What is machine language ?
2. What is programing language? Give 2 examples
3. Why is conversion of  a program written in HLL to LLL mandatory?
4. Differentiate between a compiler and an interpreter.
5. Write a detailed note on Python.
6. How is Python a simple language?
7. How is Python easy to learn?

The above exercise is a reflection of your understanding of the concept.

God Bless you

See you in the next class.