Python V25.01.08

Notes:

• Guido van Rossum Inventer of Python - Monty Python's Flying Circus. Python came into Picture just to help those people who don't know how to write a code
• James Gosling - Inventer of Java - Oak
• Dennis Ritchie - Inventer of C.
• Michael Widenius - Inventer of MySql.
• 1991 & Feb, Python came in 1989 so it's way befor java 1995.
• It is a case sensitive language
• Python can be used for :
  • Programming (for Placements/online contests/DSA)
  • Development (using a backend framework called Django)
  • Machine Learning | Data Science | Articial Intelligence | Software Devlopment | Web Devlopment | Gui.
• Websites built using Python include Google, Youtube, Instagram, Netfix, Uber. Dropbox, Nasa, Yahoo, & reddit written in Python much more.
• Python (https://www.python.org/) It also Called the General Purpose Language
• Python 1.0 - 1994
• Python 2.0 - 2000 Depricate in 2020
• Python 3.0 - 2008 New and It has lot of Features.
• PVM - Python Vertual Machine witten in Assembly language Which use Machine Level Language and convert it into binary language. Do's (Byte Code Verification)
• High Level Language (HLL) -> Python, English
• Low Level Language (LLL) -> Machine Level Language, Assembly Language-> Registers, Ic's
• Binery Language -> Byte Code -> 0 & 1
• Constructive Language - Create a Server - That's why we can use Python in web -> While "constructive language" is not a standard term, it could be used informally to describe Python’s role in building and constructing web applications, as it helps assemble server functionality efficiently.
• If you're coining a term, you could say "constructive backend language" to emphasize Python’s role in creating server-side architectures.
• Scripting Language -> Use in Hacking
• Interpriter Language (Logical Exception) (Run Time Exception) (Bytecode Verification) -> Checks Byte Code Standards.
• Compile Language (Syntactical Error) (Compile Time Error)

• Robust in Nature - Memory Management After Code Execution | Clears Memory After Usage
• Scalable Language - Compatible to Code with Every Language -> MySql, JavaScript
• Install Python:
  • python --version
  • pip --version -> python install packages
• Install jupyter:
  • jupyter --version
  • folder -> path -> cmd -> jupyter notebook
  • browser -> new -> .ipynb -> Interactive Python Notebook -> The notebook provides an environment where you can write and execute code, visualize data, and include rich text annotations interactively means Markdoun annotations.
• Integrated Devlopment Environment: & Debugger
  • Here No Need to Create New File
    • Jupiter -> Open Source -> .ipynb -> i : Interactive, py : Python, nb : Notebook.
    • Python CLI IDLE (File will Not Be Save) REPL (Read Evaluate Print Loop) Prompt in Windows Shell in Mac
  • Here Need to Create New File
    • VS Code -> Microsoft and it is Open Source to Buid Yourself.
    • Pycharm -> JetBrains
    • `Intellige1 -> Java
• Advanced Libraries - Enumration ->: AI & Ml
  • Permutation and Combination
  • Probability
  • Statistics
  • Numpy - Data Manuplation -> Heavy Focus on Arrays
  • Pandas - Data Operations
  • Matplotlib - Visualisation -> Graphs, Ven Diagrams
• print -> Returns Each Charecter on Console Screen.
  • Double Coatation & Single Coatation.
  • print("'Pratik's Birthaday'")
  • ' (Back Slash) Ignores Special Charecter. eg: print('partik's "laptop"')
• type -> Returns Data Type of Data.
• Companie Work on Python: Infosis python 20%, java 40%, deops 40%.
• Difference Between Function and Method -> Block of Code which Executes Targeted Code called Normal Function And Function Use in Class called Method.
• ( : ) -> Identation -> Dependency Code (Indentation)
• Portable -> Works on Windows|Mac|Linux, Means platform Independent.
• Implicit Conversion : ByDefault Conversion.
• Explicite Conversion : We did this By our own Hand.
• Partial Execution means 50% not 100%.
• All Progrogramming Languages are Scripting Languages. thats why here by default input value is consider as a string. like Python and JavaScript.
• Input : It allows to Except value on RunTime. (RunTime Is Class)
• ByDefault Input Value Accepts String. Beacouse All programing Languages are Scripting languages.
• Type Conversion : int(input()) float(input()) complex(input())
• Every Data Type in python is Class. we are using there Objects eg:< class int >
• In Python, everything is an object, and every object is an instance of a class. So, when you use the type() function on an object, it returns the type of the object, which is the class to which it belongs.

x = 42
print(type(x))  # Output: <class 'int'>

• x = 42: Here, x is assigned the value 42, which is an integer.

• type(x): This returns the class of the object x. Since 42 is an integer, type(x) will return <class 'int'>, indicating that x is an instance of the int class.

• Compiler:

  • It Give's an Error.
  • Compile Time Error.
  • Compile at the time of Code Writing.
  • If it fail's in Compilation process it does not show any Output Gives Direct Syntactical Error.

• Interpriter:

  • It Throw's Exception.
  • Run Time Exception.
  • Interprit at the time of code Execution.
  • It may be do the Partial Execution after Compilation and then on run time interpritation.

• Error:

  • Occours Beacouse of Syntactical Error.
  • At the Time of Compilation.
  • Compile Time Error
  • Does not Show any type of Output Just Show the Syntax Error.

• Exception:

  • Occours Beacouse of Logical Errors.
  • At the Time of Interpritation.
  • Run Time Exception
  • It Will Show Partial Output or Exception.

• Comments:

  • Use to Explin the code
  • Processor does not Execute the Commented line. It Ignores it.
  • Types:
  • Single Line Comment:
    • It denote by # - Hash
  • Multiline Comment:
    • It denote by """....""" - Thriple Cottation

• BODMAS: Border: (){}[] Order: Square & Square Root, Divide: / Multiply: *, Addition: + Subtraction: -.

Special Charecters in Python:

• Termination ( ; ): Why Optional? -> In System Libraries(Assembly Language) already /n is available after the print("..."/n) so no need to ( ; ) Terminate Line.
• Concatination ( , & + ): Join
  • print("Pratik" + "Majage")
• New Line ( \n ) -> go to new line
• Row String ( r ) -> eg: print(r'c:\docs\nayan')
• Back Slash ( \ ) -> Ignores Special Charecter. eg: print('partik's "laptop"')
• Privious Output ( _ ) -> Output of Privious Operation.

Variable:

• Variable -> The Name of Memory Location
• a = 5
• id(a) -> get address
• b = a
• Whenever you create multiple variable and in case if they have Same Data they both will point to the Same Box. they will not be getting multiple boxes for each variable. and that's where python is more memory rfficient, right Beacouse youre not getting multiple data here

Addvantages:

• Easy to Learn
• Easy to Code
• Interprited Language
• Compile Language
• Robust in Nature
• Scalable Language
• Portable
• Free & Open Source
• High Level Language
• Large Community Support
• fastest Groing Language - Devlopers & Libraries Companies & Areas ML GUI Soft.D Web.D

Data Types:

• Numerical:
  • Int (Numbers)
  • Float (Decial Point Value) (Floating Point Representation)
  • Complex (ai+bj) -> Combination of Real and Imaginary Numbers.
• Sequential:
  • List []
    • Combination of elements of Different Data Types
    • There is Defferece between List & Array
    • List is Mutable.
    • We can perform certain Operation using Methods.
  • Tuple ()
    • Ues on large Data.
    • It take less Memory Space and less Time to Execute.
    • Tuple is Immutable. We can not ( Do Operations ) Change Once We Defined.
    • Limited Methods:
      • count
      • index
    • Iteration is Fast than List.
  • Set {}
    • Collections of Elements of Unique Elements (Same Or Different).
    • Never Follow Sequence.
    • Indexing not Supported.
    • Not Support Duplicate Values.
    • Just Return Unique Value. No Duplicasy.
    • We can perform certain Operation using Methods.
  • Frozen Set
    • It Use to Create Copy of Original Set.
  • Dictionary {}
    • Key Value Pair.

  • Range ( Start : End )

• String:
  • Collections of Charecters.
  • Charecter (Char) Consider as a String.
  • In Python Value is By Default a String.
  • In a Computer Numbering start from Zero. -> String: collection of charecters in Array indexing start from 0.
  • left to Right : 0 1 2 3
  • Right to left : -1 -2 -3 -4
  • Strings are immutable. we can not change once assign.
  • len() -> Returns total length of string in int data type.
• Boolean:
  • True & False. 1 & 0.

Operators:

• There are Four types of Operators.

• Arithmatic Operator:

  • There are 8 Operators in Arithmatic Operators.
  • Addition:( + )
    • Do's Addition | Summation.
    • Symbolis: Plus ( + ).
    • Minimum 2 Operands and 1 Operator specifically Operator lies within the 2 Operands.
  • Subtraction:( - )
    • Do's Subtraction.
    • Symbolis: Minus ( - ).
    • Minimum 2 Operands and 1 Operator specifically Operator lies within the 2 Operands.
  • Multiplication:( * )
    • Do's Multiplication & Return's Product of two or more Operands.
    • Symbolis: Star | Astaric ( * ).
    • Minimum 2 Operands and 1 Operator specifically Operator lies within the 2 Operands.
  • Exponantiol:( ** )
    • Do's Exponantional make Power of that Integer.
    • Symbolis: Two Consicative (Continous) Star | Astaric ( ** ).
    • Minimum 1 Operand integer and 1 power integer Operand specifically Operator lies within the 2 Operands.
  • Division:( / )
    • Do's Division and return's the Quotient.
    • Symbolis: Division ( / ) Forword Slash.
    • Minimum 2 Operands and 1 Operator specifically Operator lies within the 2 Operands.
    • Floor Division. Base Integer Value (3.5)-> 3
    • Sealing Division. (3.5)-> 4
  • Floor Division:( // )
    • Do's Division and return's the Quotient Base Integer Value.
    • Symbolis: Division ( // ) Two Consicative (Continous) Forword Slash.
    • Minimum 2 Operands and 1 Operator specifically Operator lies within the 2 Operands.
    • Also calles as Integer Division.
  • Modulos:( % )
    • Do's Division and Returns Remainder.
    • Symbolis: Percentage ( % ).
    • Minimum 2 Operands and 1 Operator specifically Operator lies within the 2 Operands.
  • Assignment Operator:
    • Store Value in Variable

• Assignment Arithmatic Operator:

  • (+=): Addition and Assign to
  • (-=): Subtraction and Assign to
  • (*=): Multiplication and Assign to
  • (**=): Exponantiol and Assign to
  • (/=): Divide and Assign to
  • (//=): Floor and Assign to
  • (%=): Modulo and Assign to

• Relational Operator:

  • Relational operator Returns Boolean DataType. In the form of True and False.

  • Grater Than:

    • Open Angular Bracket

  • Less Than:

    • Close Angular Bracket

  • Greater than Equal To: Min

    • Open Angular Bracket With Assignment Operator
    • Given value should be Greater than Equal to the Minimum Value.

  • Less Than Equal To: max

    • Open Angular Bracket With Assignment Operator.
    • Given value should be less than Equal to the Maximum Value.

  • Equal To:

    • Two Consicutive ( Continuous ) Assignment Operator called Equal to Operator.
    • Return's True when both are Similar values.

  • Not Equal To: Not ( ! )

    • Exclametory mark with Assignment Operator
    • Return's True when both are Different values.

Assignment Operator	Equal to Operator
called Assignment Operator	called Equal to Operator
Belongs to Arithmatic Operator	Belong to Relational Operator
It Stores Value	Compare Values

• Logical Operator:

  • Returns Boolean Value.
  • Logical and:
    • Returns True when all Conditions | Inputs are True.
  • Logical or:
    • Returns False when all conditions are False.
  • Logical not:
    • Return Negation of Input value.
  • Logical NAND:
    • Not & And both makes NAND. called Negation of and
  • Logical NOR:
    • Not & Or both makes NOR. called Negation of or

• Bitwise Operators:

  • It Returns Boolean Value on the Console Screen.
  • Binary Concersion : | 32 | 16 | 8 | 4 | 2 | 1 |
  • Bin() Function use to Convert an Integer value to Binary Value also use to Identity of a binary value.
  • 0b : is use an identifier for Binary Value Identity.
  • Addition of 1+1 Bitwise Operator is 10 where 1 is Carry and 0 is Remainder.
  • Bitwise ANd ( & ): 1 1 -> 1
    • It Returns 1 when all Inputs are 1 else it Returns 0.
  • Bitwise OR ( | ): 0 0 -> 0
    • It Returns 0 when all Inputs are 0 else it Returns 1.
  • Bitwise Ex-OR ( ^ ): 0 0 -> 0 | 1 1 -> 0 | 0 1 -> 1 | 1 0 -> 1 |
    • It Called Exclusive-Or.
    • It Returns 0 when all Inputs are Same.
    • It Returns 1 when all inputs are Different.
  • Bitwise Complimentory Operator ( ~ ): ~1 -> 0
    • It Returns Complimentory of Input Value.
    • It Add 1 in in given value.
    • It also called as 1'st Compliment Operator. (~4)
    • It gives Negative Value. ( -5 )
    • Negation of Negation called as 2's Compiment. (~(~4))
    • It gives Negative Value. ( -6 )
  • Bitwise Left Shift Operator ( << ):
    • Two Consicutive Close Angular Bracket.
    • In this Operator; Value is Increases.
    • The Vacant Position after shifting are Occupied by 0.
    • print(3<<2)
  • Bitwise Right Shift Operator ( >> ):
    • Two Consicutive Open Angular Bracket.
    • In this Operator; Value is Reduce.
    • The Vacant Position after shifting are Occupied by Nothing.
    • print(3>>2)

a = 3
print(a)
# Output : 3
print(bin(a)) 
# Output : 0b11
print(bin(0b11))
# Output : 0b11

• Membership Operators:

  • Returns Boolean Value.
  • In:
    • It returns True when Specified Data is Present in given Value.
  • Not In:
    • It returns True when Specified Data is Not Present in given Value.

• Identity Operators:

  • Returns Boolean Value.
  • Object : Memory Location.
  • Mutable : List. Similar Data But Here It Represents by Different (Objects) Memory locations.
  • Immutabe : String, Tuple By Default in Python. When Similar Data is Present in Variable then it Represents by Same (Object) Memory Location.
  • All Data Types are Classes in Python.
  • Is:
    • Compares and Returns Boolean Value.
    • It Returns True when Specified Data Object and given Data Object is Similar.
  • Is Not:
    • It Returns True when Specified Data Object and given Data Object is Diffreant.
  • a=b : Explicit Conversion (we did this by our own hand) thats why it is Consider as Partially Immutable means 50% Immutable not 100%.

Control Statements:

• It is use to Control the Execution Flow of the code.
• It Helps in Efficiently Executing Code by Saving Time & Memory.
• Control Statement Executes a Prticulay Block of Code only when the Condition is True.
• if Contrl Statement:
  • It is Control Statement.
  • Declared by Kyword if.
  • if Block
  • Check Conditions
  • Efficient -> Save Time and Memory.
  • Any Positive and Negative Number consider as a True. Truty Value
  • 0 Consider as a False. Falsy Value
  • -0 -> Entity: Something that Exist. -> Tecnically Wrong Value.
  • Syntax:

if True:
    print("Welcome!!")
if False:
    print("Welcome!!")

• if-else Control Statement:
  • Else Block is Specified below if block.
  • No Conditions are Checked in Else Statement.
  • It Executes when if Statement is False.
  • If Else condition is not Declared then it Returns Blank Value. means Return's Nothing on Console Screen.
  • Syntax:

if True:
    print("Welcome!!")
else:
    print("Bye..")

• if-elif Control Statement | if-elif-ladder Control Statement:
  • Multiple Conditions are checked in elif Control Statement.
  • Starts with if Statement can Continue with many elif statements and may or may end with else.
  • Syntax:

if condition 1:
    # Code|Logic
elif condition 2:
    # Code|Logic
elif condition 3:
    # Code|Logic
else:
    # Code|Logic

• match Control Statement: | Switch Control Statement
  • It is declared by the keyword match.
  • it Contains many no of cases each case has label.
  • Data match with the case label, the case label is Execute.
  • Case is Declared by the keyword case followed by case label & identation.
  • the Wild Charecter (_) case charecter executed when the no data matches with case labels.
  • Syntax:

match value:
    case 1:
        # Code|Logic
    case 2:
        # Code|Logic
    case 3:
        # Code|Logic
    case _: # Default Case
        # Code|Logic

Loops:

• Repetetion - Iteration
• Help to Execute Progressively | Repeatedly and with Enhancement.
• For Loop
  • Use keyword: for
  • in(Membership Operator)
  • range() - Predefined Function -> Accept 3 pameters -> Start|end|Difference eg:range(1,6), range(5,0,-1)
  • for i in range(5,0,-1):
• break : It Terminates the Execution of Code.
• continue : Omit the Perticular Situation.

Function:

• It is Entry or Block of Code which Executes Targeted Logic.
• It Identifies by a Function Name.
• By using def keyword.
• () : Function
• : -> Dependancy Code (Identation)
• Single Python code has Multiple Functions.
• Function Name should be Unique.
• Function Defination - Parameters
• Function call - Arguments
• Reusability: Write Once Use Multiple Time.
• Function always Jump Upword Direction thts why Function call is always below the Function Defination.
• return keyword: Return the value where the function call.
• A value can be use outside the function by using return keyword.
• We can store the value in new variable by using return keyword.
• We can use multiple functions in pirnt funcrions.
  • Non-Parametrise Functions.
  • Parametrise Functions.
    • No of Arguments should match with the No of Parameters.
    • Separate by Commas
    • Parameter - Defination
    • Argument - Call
• Ambiguity: Multiple Functions has Same Name.
• Priority to Nearest Closest Function.
• Compatibility : Same Data Types.

def Info():
    print("Hello I.T")
Info()