Programming Fundamentals:
=========================
KEYWORDS
=========
	==> ARE RESERVED WORDS/BUILT-IN WORDS
		TO DEFINE THE SPECIAL ACTION WHILE CODING/SCRIPTING, KEYWORDS ARE USED.
	==> 35 KEYWORDS
	==> MODULE ==> keywords
	==> Syntax for the importing of the keyword module is:
		import keywords
	==> keywords ==> name (kwlist),
		is pointing to all the keywords
	Syntax:
		to make display
			keywords.kwlist

Q: Write a script to display all the keywords of python.

import keyword

kw = keyword.kwlist
print(kw)

['False', 'None', 'True', 'and', 'as', 'assert', 'async', 'await', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try', 'while', 'with', 'yield']

==============================================
COMMENTS:
=========
==> ARE OPTIONAL (BECAUSE WITHOUT THE COMMENTS ALSO, THE PROGRAM CAN EXECUTE)
==> ARE SUGGESTABLE
==> ARE READABLE
==> NOT FOR THE EXECUTION
==> WE CAN ADD COMMENTS IN ANYWHERE OF THE PROGRAM.
==> COMMENTS CAN BE WRITE IN TWO WAYS:
	1) SINGLE LINE COMMENTS ==> #
	2) MULTILINE COMMENTS ==> """ """

# Here we are discussing comments
"""
Single line comments can always start with #
whereas multiline comments are always in between triple comments.
"""
# WRITE A SCRIPT TO ADD TWO NUMBERS.
a = 10
b = 20
"""
here, we have defined two values 
with names: a and b
"""
c = a + b
# we were added a and b and store into c
# now, i am printing
print(c)
# the program was closed.

=================================================

IDENTIFIER
===========
==> a name
	used to name any entity within the program.
like: variables, classes, objects, methods, functions etc.

Rules for Identifier:
=====================
1) Name should define with:
	Alphabets (Upper case/lower case)
	Digits (0 to 9)
	Underscore sign
2) No identifier should start with a digit, but the digit can be between the identifier.
ex: 9abc = 10 ==> Error
abc9_23 = 100 ==> correct
3) identifier is not a keyword
4) Case Sensitive
	name in upper case
	same name in lower case ==> consider as different
	ex: else = 12 ==> syntax error
	Else = 23
	ELSE = 32 ==> correct
5) No other special characters (@,space.<>?) allowed in identifier.
6) No limit in length of identifier.

a = 12
# 9a = 24   Syntax Error
_a9 = 24
# else = 123
Else = 23
ELSE = 32
# python@program = 123

print(a)
# print(9a)
print(_a9)
# print(else)
print(Else)
print(ELSE)
# print(python@program)

Note:
====
_name ==> Protected data
__name ==> Private data representation
name ==> Public data representation

__init__()
__add__()
__sub__()
==================================================
VARIABLES
-=========
==> Named memory
	to store any value.

Dynamically Typed Language
==========================
Programming Languages
	classified into three types:
		1) Statically Typed : C
			int a = 12.12;
			a = 12
		2) Strongly typed: Java
			Syntax for the data definition:
				datatype identifier = value;
			ex: int a = 12;
			int a = 12.23;==> error
		3) Dynamically typed
			Syntax:	
				identifier = value
			the programming system can automatically detect its type based value assignment.
		ex: a = 12 (Integer)
		b = 1.23 (Float)

type():
=======
==> can give the type of the data
Syntax:
	type(identifier)

id():
=====
==> get the address location (heap memory)
Syntax:
	id(identifier)

a = 12
b = 1.23

print(type(a))
print(type(b))

# type(a)

print(id(a))
print(id(b))