Courses TRB CSI Python Programming Python interpreter and interactive mode

Python Interpreter and Interactive Mode

Python Interpreter Python Interpreter என்பது நாம் எழுதும் Python source code-ஐ read செய்து, process செய்து, execute செய்ய உதவும் software. Simple-a சொன்னால்: Python code-க்கும் computer-க்கும் நடுவில் வேலை செய்யும் execution system தான் Py…

Free Beginner 15 min 92 cards 19 programs 10 MCQs v2

Definition

Meaning

Python Interpreter

Python Interpreter என்பது நாம் எழுதும் Python source code-ஐ read செய்து, process செய்து, execute செய்ய உதவும் software.

01Simple-a சொன்னால்

Python code-க்கும் computer-க்கும் நடுவில் வேலை செய்யும் execution system தான் Python Interpreter.

Interactive Mode

Interactive Mode என்பது Python commands-ஐ one by one type செய்து Enter press செய்தவுடன் immediate result பெறும் mode.

02Python Interactive Mode-ன் முக்கிய prompt

Simple Explanation

Core idea

என்று எழுதுகிறோம்.

01நாம் Python-ல்

print("Hello")

02Detail 02

Computer நேரடியாக Python syntax-ஐ புரிந்து கொள்ளாது.

03அதனால்

1. 1Python Code
2. 2Python Interpreter
3. 3Code Process ஆகும்
4. 4Execute ஆகும்
5. 5Output கிடைக்கும்

Program

Example

Python 1 lines Copy

1print("Hello")

print("Hello")

Verified output

Hello

Learning Run Mode — this is the output the author verified, not a live execution.

Run Explain Full screen Save

Output

Copy Expand

Hello

Context

இதில் Python Interpreter தான் print() என்ன செய்ய வேண்டும் என்று புரிந்து execute செய்கிறது.

Interactive Mode Simple Explanation

01Python open செய்ததும் சில environments-ல்

என்று வரும்.

02இதை பார்த்தால்

Python இப்போது command வாங்க ready-ஆக இருக்கிறது

என்று அர்த்தம்.

Program

Example

Python 1 lines Copy

1>>> 10 + 20

>>> 10 + 20

Explain Full screen Save

Explanation

Core idea

30

01இங்கு

10 + 20 type செய்கிறோம்.

02Detail 02

Enter press செய்கிறோம்.

03உடனே

30

04Detail 04

வருகிறது.

05Detail 05

இதுதான் Interactive Mode.

Explains the program above

Flow

1. 1Python Source Code
2. 2Interpreter receives the code
3. 3Syntax checked
4. 4Internal processing / bytecode generation
5. 5Python Virtual Machine executes
6. 6Result / Output

1. 1Programmer writes Python code
2. 2Python Interpreter
3. 3Execution
4. 4Output

1. 1Python Shell Open
2. 2User types a command
3. 3Press Enter
4. 4Interpreter executes it
5. 5Immediate Output
6. 6Next >>> prompt appears

Program

Example

Python 1 lines Copy

1>>> 5 + 5

>>> 5 + 5

Explain Full screen Save

Explanation

Core idea

10

01Detail 01

Last >>> என்ன சொல்கிறது?

02Detail 02

Next command type செய்ய Python ready.

03Detail 03

Interactive Mode-க்கு separate programming syntax கிடையாது.

04Detail 04

Python Shell-ல் normal Python statement type செய்ய வேண்டும்.

Explains the program above

Syntax

General form

Python 1 lines Copy

1>>> expression

>>> expression

Explain Full screen Save

Program

Example

Python 1 lines Copy

1>>> 5 + 3

>>> 5 + 3

Explain Full screen Save

Explanation

Core idea

8

01Detail 01

Variable:

Explains the program above

Program

Python 2 lines Copy

1>>> x = 10
2>>> x

>>> x = 10 >>> x

Explain Full screen Save

Explanation

Core idea

10

01Detail 01

Print statement:

Explains the program above

Program

Python 1 lines Copy

1>>> print("Python")

>>> print("Python")

Explain Full screen Save

Explanation

Core idea

Python

01Detail 01

Simple Addition

Explains the program above

Program

Python 1 lines Copy

1>>> 10 + 20

>>> 10 + 20

Explain Full screen Save

Explanation

Core idea

30

01Detail 01

Using Variables

Explains the program above

Program

Python 3 lines Copy

1>>> x = 10
2>>> y = 20
3>>> print(x + y)

>>> x = 10 >>> y = 20 >>> print(x + y)

Explain Full screen Save

Explanation

Core idea

30

01Detail 01

Multiplication

Explains the program above

Program

Python 3 lines Copy

1>>> a = 5
2>>> b = 4
3>>> a * b

>>> a = 5 >>> b = 4 >>> a * b

Explain Full screen Save

Explanation

Core idea

20

01Detail 01

String

Explains the program above

Program

Python 2 lines Copy

1>>> name = "Python"
2>>> print(name)

>>> name = "Python" >>> print(name)

Explain Full screen Save

Explanation

Core idea

Python

01Detail 01

Comparison

Explains the program above

Program

Python 1 lines Copy

1>>> 10 > 5

>>> 10 > 5

Explain Full screen Save

Explanation

Core idea

True

01Detail 01

Division

Explains the program above

Program

Python 1 lines Copy

1>>> 10 / 2

>>> 10 / 2

Explain Full screen Save

Explanation

Core idea

5.0

Explains the program above

Important

1. 01

   Python / operator normally floating-point result கொடுக்கும்.

2. 02So

   >>> 6 / 2

3. 03

   3.0

Explanation

Program 7

Core idea

Direct Expression

01Detail 01

Interactive Mode-ல் print() இல்லாமலேயே expression result பார்க்கலாம்.

Program

Python 1 lines Copy

1>>> 100 + 200

>>> 100 + 200

Explain Full screen Save

Explanation

Core idea

300

01ஆனால் Script Mode-ல்

100 + 200

02Detail 02

என்று மட்டும் எழுதி run செய்தால் normally screen output கிடைக்காது.

03Detail 03

அங்கு:

Explains the program above

Program

Python 1 lines Copy

1print(100 + 200)

print(100 + 200)

Explain Full screen Save

Explanation

Core idea

என்று எழுத வேண்டும்.

01Detail 01

இது முக்கியமான difference.

Explains the program above

Program

Example

Python 3 lines Copy

1>>> x = 10
2>>> y = 20
3>>> print(x + y)

>>> x = 10 >>> y = 20 >>> print(x + y)

Verified output

30

Learning Run Mode — this is the output the author verified, not a live execution.

Run Explain Full screen Save

Output

Copy Expand

30

Program

Another example

Python 1 lines Copy

1>>> 5 * 4

>>> 5 * 4

Verified output

20

Learning Run Mode — this is the output the author verified, not a live execution.

Run Explain Full screen Save

Output

Copy Expand

20

Program

Another

Python 1 lines Copy

1>>> "Hello" + " Python"

>>> "Hello" + " Python"

Verified output

'Hello Python'

Learning Run Mode — this is the output the author verified, not a live execution.

Run Explain Full screen Save

Output

Copy Expand

'Hello Python'

Line by Line

1

x = 10

x என்ற variable create ஆகிறது. அதில் value: 10 store செய்யப்படுகிறது. இங்கு: x → Variable name = → Assignment operator 10 → Value

2

y = 20

y என்ற variable-க்கு 20 assign செய்யப்படுகிறது. Current values: x = 10 y = 20

3

print(x + y)

முதலில் Python: x + y calculate செய்கிறது. அதாவது: 10 + 20 Result: 30 பிறகு print(): 30 screen-ல் display செய்கிறது.

Dry Run

Execution traceRead top to bottom · highlighted cells show the current value4 states

Step	Statement	x	y	Output
01Iteration 1	x = 10	10	-	-
02Iteration 2	y = 20	10	20	-
03Iteration 3	x + y evaluated	10	20	30
04Iteration 4	print() displays result	10	20	30

Dry Run

Execution traceEvaluate the expression from left to right

TraceInteractive Mode Dry Run

Input

Copy Expand

>>> 5 * 4

Dry Run

Execution traceRead top to bottom · highlighted cells show the current value5 states

Step	Process	Result
01Iteration 1	User enters 5 * 4	Expression received
02Iteration 2	Interpreter identifies *	Multiplication
03Iteration 3	5 × 4 calculated	20
04Iteration 4	Result displayed	20
05Iteration 5	>>> appears again	Ready for next command

Comparison

Interactive Mode vs Script Mode

Point	Interactive Mode	Script Mode
Working style	One command at a time	Complete program
Prompt	>>>	Normally no >>>
Output	Immediate	After program execution
File required	No	Usually Yes
File extension	Not required	.py
Suitable for	Small testing	Large programs
Learning	Very useful	Also useful
Code saving	Normally temporary session	Saved permanently
Debugging	Quick testing easy	Better for full programs
Projects	Not ideal	Recommended

Comparison

Interpreter vs Compiler

Point	Interpreter	Compiler
General idea	Executes program through runtime processing	Translates program before/for execution
Error testing	Often encountered during execution	Often many compile-time errors reported during compilation
Development	Quick experimentation	Build/compile step common
Python	Commonly called interpreted	-
C/C++	-	Commonly called compiled languages

Important

1. 01Python பற்றி technically deep-a கேட்டால்

   Python source codebytecodePython Virtual Machine execution

2. 02

   என்று சொல்லலாம்.

3. 03ஆனால் basic competitive exam answer

   Python is an interpreted language.

Important

1. 01

   Python Interpreter executes Python code, while Interactive Mode allows the user to enter Python statements one by one and get immediate results.

2. 02

   இதை கண்டிப்பாக நினைவில் வைக்க வேண்டும்.

3. 03

   Very Important Prompts

4. 04

   Primary Prompt

5. 05

   Python next instruction வாங்க ready என்பதை குறிக்கும்.

6. 06

   Secondary / Continuation Prompt

7. 07

   ...

8. 08

   Multi-line statement இன்னும் complete ஆகவில்லை என்பதை காட்டும்.

Program

Example

Python 2 lines Copy

1>>> if 10 > 5:
2...     print("Yes")

>>> if 10 > 5: ... print("Yes")

Verified output

15

Learning Run Mode — this is the output the author verified, not a live execution.

Run Explain Full screen Save

Explanation

Core idea

...
Yes

Explains the program above

Common Mistake

Error 1

Context

>>>-ஐ Python program file-ல் எழுதுவது

01Wrong

>>> x = 10
>>> print(x)

இந்த >>> என்பது Python code இல்லை.

இது Interactive Shell prompt.

02Script file-ல் எழுத வேண்டியது

x = 10
print(x)

Common Mistake

Error 2

Context

Interactive result மற்றும் print() ஒன்றே என்று நினைப்பது

01Interactive Mode · >>> 10 + 20

30

print() இல்லாமலே result தெரியும்.

02ஆனால் Python file · 10 + 20

என்று மட்டும் இருந்தால் visible output வராமல் இருக்கலாம்.

03Correct

print(10 + 20)

Common Mistake

Error 3

Python Interpreter ஒரு compiler அல்ல என்று absolute-a சொல்வது

Basic exam-ல் Python interpreted language.

ஆனால் Python implementation internally bytecode compilation செய்யலாம்.

Correct understanding:

Python is generally classified as an interpreted language, although CPython internally compiles source code to bytecode before execution by the Python Virtual Machine.

Common Mistake

Error 4

Context

... Error symbol என்று நினைப்பது

01Wrong understanding

...

means error.

02Correct

... என்பது generally continuation prompt.

Memory Trick

01Think

>>> = Give me the next command

02Python சொல்கிறது

1. 1"Next command என்ன?"Interpreter Memory TrickI = Interpreter = Instruction ExecutorInterpreter → Instruction-ஐ execute செய்ய உதவும்.Interactive Memory TrickInteractive = Immediate InteractionType
2. 2Enter
3. 3Immediate Result.py Memory TrickPY = Python

03Python program file

.py

TRB Point

TRB Point 1

Python is commonly classified as an interpreted high-level programming language.

TRB Point

TRB Point 2

Python Interactive Mode-ன் primary prompt:

TRB Point

TRB Point 3

Continuation / Secondary prompt:

...

TRB Point

TRB Point 4

Python source file extension:

.py

TRB Point

TRB Point 5

Interactive Mode is mainly used for:

quick testing, calculations, experimentation and learning.

TRB Point

TRB Point 6

Script Mode is mainly used for:

saving and executing complete Python programs.

TRB Point

TRB Point 7

1. 01Common Python execution concept

   Source Code

2. 02

   ↓

3. 03

   Bytecode

4. 04

   ↓

5. 05

   Python Virtual Machine

6. 06

   ↓

7. 07

   Execution

TRB Point

TRB Point 8

Interactive Mode generally executes:

one command or statement at a time.

Interview Point

Question 1

What is a Python Interpreter?

Answer

A Python Interpreter is the software/runtime system that processes and executes Python code. In common implementations such as CPython, the source code is compiled into bytecode and then executed by the Python Virtual Machine.

Interview Point

Question 2

What is Interactive Mode in Python?

Answer

Interactive Mode allows us to enter Python commands one at a time and get immediate results. It commonly displays the >>> primary prompt.

Interview Point

Question 3

What is the difference between Interactive Mode and Script Mode?

Answer

Interactive Mode is mainly used for quick testing and immediate results. Script Mode stores Python code in a .py file and is better for larger and reusable programs.

Interview Point

Question 4

What does >>> mean in Python?

Answer

>>> is the primary prompt of the Python interactive shell. It indicates that Python is ready to accept the next command.

Interview Point

Question 5

What does ... represent?

Answer

... is commonly called the secondary or continuation prompt. It appears when Python expects additional lines to complete a multi-line statement.

MCQ

71Python is commonly classified as a:

A Markup language B Interpreted language C Query language D Styling language

Choose one answer Try again

MCQ

72Which is the primary prompt in Python Interactive Mode?

A ### B >>> C ... D <<<

Choose one answer Try again

MCQ

73Which prompt is generally used for continuation?

A >>> B ... C /// D ***

Choose one answer Try again

MCQ

74What is the extension of a Python source file?

A .pt B .pyt C .py D .python

Choose one answer Try again

MCQ

75Which mode is most suitable for quick testing?

A Script Mode B Interactive Mode C Design Mode D Database Mode

Choose one answer Try again

MCQ

76What is the output? >>> 5 * 4

A 54 B 20 C 9 D Error

Choose one answer Try again

MCQ

77What is the output? >>> 10 / 2

A 5 B 5.0 C 102 D Error

Choose one answer Try again

MCQ

78Which is more suitable for a large application?

A Interactive Mode B Script Mode C Calculator Mode D Prompt Mode

Choose one answer Try again

MCQ

79Consider: >>> x = 10 >>> x What is displayed?

A x B 0 C 10 D Error

Choose one answer Try again

MCQ

80Which of the following is NOT part of Python code?

A print() B Variable C >>> shell prompt D Expression

Choose one answer Try again

Practice

Practice 1

Interactive Mode-ல்:

5 + 10

run செய்து output கண்டுபிடிக்கவும்.

Output

Expected Output

Copy Expand

15

Practice

Practice 2

Two variables create செய்யுங்கள்:

x = 25
y = 15

இரண்டையும் add செய்து result பார்க்கவும்.

Practice

Practice 3

கீழே உள்ள code output கண்டுபிடிக்கவும்:

>>> a = 5
>>> b = 6
>>> a * b

Answer:

30

Practice

Practice 4

Interactive Mode-ல் உங்கள் பெயரை store செய்து print செய்யுங்கள்.

Program

Example

Python 2 lines Copy

1name = "Nagarajan"
2print(name)

name = "Nagarajan" print(name)

Explain Full screen Save

Practice

Practice 5

இந்த expressions-ஐ execute செய்யுங்கள்:

20 + 30
50 - 10
5 * 8
100 / 4

Practice

Practice 6

இந்த statement output என்ன?

>>> 25 > 10

Answer:

True

Practice

Practice 7

Python Interactive Mode மற்றும் Script Mode-க்கு 5 differences எழுதுங்கள்.

Practice

Practice 8

Fill in the blanks:

Python Interactive prompt is .
Python continuation prompt is .
Python file extension is .
Python is commonly a/an language.
Large Python programs are usually stored in ____ mode.

Answers:

...
.py
interpreted
Script

Summary

1. 01Python Interpreter Python code-ஐprocess செய்து execute செய்ய உதவுகிறது.
2. 02Pythonis commonly called an interpreted language.
3. 03Interactive Modecommand-by-command executionக்கு பயன்படுகிறது.
4. 04Interactive Mode immediate resultகொடுக்கிறது.
5. 05>>> என்பது Python Primary Prompt.
6. 06... என்பது Secondary /Continuation Prompt.
7. 07Python source file extension .py.
8. 08Interactive Mode quick testingக்குuseful.
9. 09Script Mode large and reusableprogramsக்கு suitable.
10. 10CPython internally source code-ஐbytecode-ஆக compile செய்து Python Virtual Machine மூலம் execute செய்கிறது.

Quick Revision

1. 01Interpreter → Python code executeசெய்ய உதவும்.
2. 02Interactive Mode → Type → Enter →Immediate Result.
3. 03>>> → Primary Prompt.
4. 04... → Continuation Prompt.
5. 05.py → Python source fileextension.
6. 06Interactive Mode → Small testing.
7. 07Script Mode → Large programs.
8. 08Python → Commonly classified asinterpreted.
9. 09PVM → Python Virtual Machine.