demo.txt

* python is a interpreted , general purpose , object oriented programming
language[1989]
* Guido Van Rossum , he introduced the python. Monty pythons flying circus.

FEATURES OF PYTHON:
* Simple and easy to learn
* Freeware and opensource
* High level programming language
* Platform independent
* Portability
* Dynamic typing programming language
* Both procedure oriented and object oriented programming language
* interpreted programming language
* Extensible
* Embeded
* Extensive library

LANGUAGE FUNDAMENTALS:
1.IDENTIFIERs :
* A name in the pythonn program is called as identifier.
* It can be a class name or function or module name or variable name.

RULES : 
1.Alphabates(a-z/A-Z)
2.Numbers(0-9)
3.Under score(_)
4.Not allowed to start with number

Ex: cash = 100 --> valid
cas&h = 100 ---> Invalid

123total = 100 --> Invalid
total = 100 --> valid

total = 100
TOTAL = 200

firstNameLastName() --> camelcase(java)
first_name_last_name() --> snake case(python)
FirstNameLastName() --> Pascal case
first-name-last-name --> kebab case(lisp programming language)

It should print all the keywords in the python.

import keyword
keyword.kwlist

['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']
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

DATA TYPES:
There are 2 types, 1.Fundamental datatype  2. collection datatype

1.FUNDAMENTAL DATATYPE:
* The basic building block of programming datatypes.
* There are : int , float , string , bool , complex.
* It is also called as primitive datatype.
* Data types are ones in which we can only store one value in their variables, never more than one value of the same type.

2. COLLECTION DATATYPE:
* It is used to store the data in containers are commonly known as datastructures.
* There are : List , tuple , dictionary , bytes , bytearray , set , frozenset , range , None.
* It is also called as non-primitive datatype.
* Data types are can store the multiple datatypes in one datatype.

LIST:
* It is a ordered mutable collection of elements.
* It is denoted by [].
* Insertion order is preserved.
* Hetrogenious objects are allowed.
* Duplicate values are allowed.
* Growable in nature.
* Indexing and slicing supported.

TUPLE:
* It is a ordered immutable collection of elements.
* It is denoted by ().
* Insertion order is preserved.
* Hetrogenious objects are allowed.
* Duplicate are allowed.
* Growable nature are not allowed.
* Indexing and slicing supported.

SET:
* It is a unordered and mutable collection of unique elements.
* It is denoted by {}
* Insertion order is preserved.
* Hetrogenious objects are allowed.
* Duplicates are not allowed.
* Doesnot perform Indexing and slicing.

DICTIONARY:
* It is a ordered and mutable collection of elements.
* It is denoted by {}.
* It represents the key value pair in the dictionary.
* Insertion order is preserved.
* Hetrogenious objects are allowed.
* Duplicate are not allowed.
* Indexing and slicing are not allowed.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* When list and tuple comparison by default datatype is "TUPLE".
* When set and dictionary comparison by default datatype is "DICTIONARY".
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

OPERATORS:
* It is used to perform the operations on the data.
* It is a symbol that performs certain operations.
* There are 5 types are there : 1.Arithmetric operator  , 2.Relational operator , 
3.Assignment operator , 4.Logical operator , 5.Bitwise operator , 6..Equality operator , 7.Special operator , 8.Ternary operator
-------------------------------

1.ARITHMETIC OPERATORS:
* It is used to perform the basic mathamatics between 2 arguments.
* There are : +,-,*,/,//,%,**
* / -> when 2 arguments are perform division(/) it gives the decimal[float] value.
* // -> when 2 arguments are perform (//) it gives the integer value.
* Atleast one arguments are one float and one integer value it should return the float value.

Example:
10/2 #5.0  ,  10.0/2 #5.0 
10//2 #5   ,  10.0//2 #5.0

Note : 
* If want to use the string operator for both arguments,it should return the error  ----> Eg: 'sunny'+3 #Invalid , 'sunnu' + '3' # valid
-----------------------------------

2.RELATIONAL OPERATOR:
* It is used to compare the 2 arguments.
* There are: <,<=,>,>=
* we can apply the Relational operator for 'str' type also.

Example:
'sunny'<'mahesh' ---> By comparing the both string python complier observe the starting letter of both strings and give the output.
* By comparing the 's' ASCII value and 'm' ASCII value in the both arguments.   ord(s) #115 , ord(m) #109
----------------------------------------

3. Equality operator:
* It is used to compare the value of given 2 arguments.
* There are : == , !=

Example: 
10=='sunny' #False 
10==10.0 #True
10=='10' #False
10.10 == 10.1 # True
----------------------------------------------------

4.Logical operator:
* It is used to combine multiple conditions together and evaluate them as a single boolean expression.
* There are 3 types are there : 'and','or','not'.
* 'and' --> If both arguments is True then only result is true.
* 'or' --> If one argument is True then result is true.
* 'not' --> Complement.

Example: 
    True and False #False
	True or False #True
	not False #True

For non-boolean type behaviours:
--------------------------------------------------
-->0 means False
-->non-zero means True
-->Empty string always False.

x and y:
------------
	If x evaluates to False return x otherwise return y.
Ex:
10 and 20 #20
0 and 10 #0

-->If the first argument is zero then result is zero otherwise result y.

x or y:
----------
	If x evaluates to True then result is x otherwise result is y.
Ex:
	10 or 20 #10
	0 or 20 #20

not x:
---------
-->If x evaluates to False then the result is True otherwise False
Ex:
not 10 #False
not '' #True

Ex:
'sunny' and 'mahesh' #'mahesh'
'' and 'sunny' #''
'' or 'sunny' #'sunny'
'sunny' or '' #'sunny'
not 'radhika' #False 
10 or 10/0 #10
0 or 10/0 #ZeroDivisionError
--------------------------------------------

5. Bitwise operator:
* It is used to perform Bitwise calculations on integers.
* The integers are converted into binary format and then operations are performed bit by bit.
* It works on integers only and the final output is returned in the decimal format.

------------------------------
			&, |, ^, ~, <<,  >>

0 & 0==>0			0 | 0==>0			0 ^ 0==>0
0 & 1==>0			0 | 1==>1			0 ^ 1==>1
1 & 0==>0			1 | 0==>1			1 ^ 0==>1
1 & 1==>1			1 | 1==>1			1 ^ 1==>0

&==>If both bits are 1 then only result is 1 otherwise 0.
|==>If atleast one bit is 1 then the result is 1 otherwise result is 0.
^==>x-or==.If bits are differentr then only result is 1 otherwise result is 0.
~==>Bitwise complement operator

Ex:
	4 & 5 #4
	4 | 5 #5
	4 ^ 5 #1
	~4 #-5

<<(left shift operator):
---------------------------------
	10<<2 #40

>>(Right shift operator):
-----------------------------------
	10>>2 #2

Ex:
True & False #False
True | False # True
True ^ False #True
~True #
True << 2 #4
True >> 2 #0
-----------------------------------

6.Assignment operators:
-------------------------------------
-->We can use assignment operator to assign a value to the variable.
Ex:
		x = 10

-->We can cobmine assignment operator with some other operator to form compound assignment operator.
Ex:
		x += 10 ===>x = x+10

-->Compound assignment operators are:
		+=,-=,*=,/=,..............

-->No increment and decrement operators in python.
Ex:
		x++(Invalid)
		x--(Invalid)
		+(+x) ==>(valid)
		-(-x)==>(valid)
-----------------------------------------------

7.Ternary Operator:
------------------------------
-->In java we can use:
	x = (condition)?first value:second value

Ex:
	x = (10<20)?30:40
	print(x)

-->In python we can use:
			x = first value if condition else second value.
Ex:
	x = 30 if 10<20 else 40
	x #30
	x = 30 if 10>20 else 40
	x #40

-->first value if condition-1 else second value if condition-2 else third value

x = 10 if 20<30 else 40 if 50<60 else 70
x #10
x = 10 if 20>30 else 40 if 50<60 else 70
x #40
x = 10 if 20>30 else 40 if 50>60 else 70
x #70
-------------------------------------------

8.Special Operators:
--------------------------------
1.Identity operators:
	We can use identity operators for address comparision. 2-identity operators are available.
							-->is
							-->is not
r1 is r2 returns True if both r1 and r2 are pointing to the same object.
r1 is not r2 returns True if both r1 and r2 are not pointing to the same object.

Ex:
	a = 10
	b = 10
	a is b #True
	a is not b #False
Ex:
	l1 = ['one','two','three']
	l2 = ['one','two','three']
	l1 is l2 #False
	l1 == l2 #True

Note:
	We can use is operator for address comparision where as == operator for content comparision.

2.Membership operator:
	We can use membership operators to check whether the given object present in the given collection.(It may be list,tuple,string....)

in==>Returns True if the given object present in the specified collection.
not in==>Returns True if the given object not present in the specified collection.

Ex:
	l = [10,20,30]
	30 in l #True
	50 in l #False
	50 not in l #True
	30 not in l #False

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

INPUT AND OUTPUT STREAMS:

---------->  INPUT:
* There are 2 functions are:
	1.raw_input()
	2.input()

1. Raw_input():
* This function always read the data from the keyword in the form of string format. 
* we have to convert that string type to our required type by using type casting methods.

2. Input():
* It is a function can be used to read data directly in our required format.
* we are not required to perform the type casting.

Note:
* But in python-3 version we have only input() method and raw_input() method is not available.
* python-3 input() function behaviour exactly same as raw_input() method in python-2 i.e every input value is treated as str type only.

EVAL FUNCTION:
* eval() function can take a string and evaluate the result.
* x = eval(input("Enter a expression: "))
  print(x)

COMMAND LINE ARGUMENTS:
* The arguments which are passing at the time of execution are called as command line arguments.
 Example : D:\Coaching-Python-Full-Stack\input and Output> py.input.py 

* withinn the python program this command line args are available in "argv". which is present in "sys" module.
* The type of arg is not an array it is a list.

Note:
* argv[0] represents name of the program,but not the first command line argument.
* argv[1] represents first command line argument.
* argv[2] represents second command line argument.

Example:
* from sys import argv
print(type(argv))

-------------> OUTPUT:

Output Streams:
-------------------------
We can use print() function to display output

Form-1:print() without arg
-----------------------------------------
Just it prints new line character

Form-2:print(string)
------------------------------
print('Hello World')
print('Hello\nWorld')
print('Hello\tWorld')
print(5*'Hi ')
print('Hi '*5)
print('Hello'+'World')
print('Hello','World')

Form-3:print() with variable number of args
------------------------------------------------------------------
a,b,c = 10,20,30
print('The values are:',a,b,c)
	
-->Bydefault output values are separated by space. If we want we can specify separator by using 'sep' attribute.

a,b,c = 10,20,30
print(a,b,c,sep=':')
print(a,b,c,sep='-')

Form-4:print() with end attribute
--------------------------------------------------
print('Hello')
print('Radhika')
print('How r u?')

-->If we want output in the same line with space.

print('Hello',end=' ')
print('Radhika',end=' ')
print('How r u?')

Form-5:print(object) statement
-----------------------------------------------
We can pass any object(like list,tuple,set.....) as arg to the print.

Ex:
	l = [10,20,30]
	t = (10,20,30)
	print(l)
	print(t)

Form-6:print(string,variable list)
-------------------------------------------------
s = 'Mahesh'
a = 50
s1 = 'Python'
s2 = 'Django'
print('Hello',s,'your age is:',a)
print('You are teaching',s1,'and',s2)

Form-7:print(formatted string)
----------------------------------------------
%d-->int
%f-->float
%s-->string type

Syn:
		print('formatted string'%(variablelist))

a,b,c = 10,20,30
print('a value is %d'%a)
print('b value is %d and c value is %d'%(b,c))

Form-8:print() with replacement operator {}
------------------------------------------------------------------
name = 'Mahesh'
sal = 10000
gf = 'Sunny'
print('Hello {} your salary {} and your GF {} is waiting'.format(name,sal,gf))
print('Hello {0} your salary {1} and your GF {2} is waiting'.format(name,sal,gf))
print('Hello {n} your salary {s} and your GF {g} is waiting'.format(s=sal,g=gf,n=name))