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    BEST PYTHON TUTORIAL FOR BEGINNERS

    Best Python Tutorial For beginners

    To all Python lovers, here I’m writing an easy tutorial for learning the python programming language.

    As you know with the growth in Machine Learning & Artificial Intelligence, the future of the industry will be dependent on AI-based applications. Python is the stepping stone to start your career in automation and data science.

    Few real-time application of Python:

    1. Web Scraping
    2. Image Processing
    3. Machine Learning & AI
    4. Automate excel & CSV files
    5. Scientific & Numeric Computing
    6. Email Automation
    7. Data Analysis
    8. Data Visualization
    9. Web Development using Django
    10. Gaming development

    Benefits of using Python over other programming languages:

    All top companies like Google, Facebook, Microsoft, Youtube, Quora, Yahoo, Salesforce are currently using Python.

    This tutorial will cover:-

    1. Python Installation
    2. Python Data Types
    1. Operators
    2. Conditionals Statements
    3. Loops
    4. Functions
    5. File Handling

    Python Installation

    1. Download python latest version from anaconda.com/download/
    2. Complete setup installation
    3. Install visual studio code from code.visualstudio.com
    4. Start using Jupyter notebook

    Variables

    Python stores data/ values in memory using a variable. A variable is a name given by you, to which you assign a piece of data that is stored in an area of the computer’s memory, allowing you to refer to that data when you need to later in the program

    a = 10
    b = 'Welcome to Gyansetu!'
    c = 10.11
    print(a,b,c)
    
    ## output:
    ## 10 Welcome to Gyansetu! 10.11
    

    Here the variables are a, b, c

    Python Data Types

    python data types

    Numbers:

    There are 3 types of Numbers:

    1. Integer
    2. Float
    3. Complex
      1. Integer (int): Integer is a non-decimal number formed by the combination of 0 – 9 digits.
      2. Float (float): Afloat is a decimal number that can be represented on a number line.
      3. Complex (complex): They are numbers that consist of an imaginary number and a real number.

    Different types of numbers

    a = 10   #integer
    b = 43.49     #float
    c = 1 + 2j       #complex

     To accept values from user input

    x = input("Enter any number : ")
    y = input("Enter any number : ")
    z = input("Enter any number : ")
    print(x,y,z)
    
    ## output:
    ## Enter any number : 2
    ## Enter any number : 3
    ## Enter any number : 1
    ## 2 3 1
    

    To know the type of data:

    print(type(x))
    print(type(y))
    print(type(z))
    ## output:
    ## 
    ## 
    ## 
    

    String

    A string in Python consists of a series or sequence of characters – letters, numbers, and special characters.

    Strings can be indexed – often synonymously called subscripted as well. Similar to C, the first character of a string has the index 0.

    How to print a string

    a = "sahil"
    b = 20
    c = 30
    print("%d-%d-%d" % (a,b,c))
    
    ## output:
    
    ## This will give error because %d is used in print for a and a is a string, %d is used for integer values
    

    ### Another way to solve the error

    a = "sahil"
    b = 20
    c = 30
    print("%s-%d-%d" % (a,b,c))
    ## output:
    ## sahil-20-30
    ## %s is used for string values
    

    How to print a string using .format

    a = "sahil"
    b = 20
    c = 30
    print("{}-{}-{}".format(a,b,c))
    ## output:
    ## sahil-20-30
    

    Indexing in Python:

    Indexing # starts from 0 to n – 1 where n is the length of string use []

    Example to understand indexing:

    python strings

    s = "Hello World!"
    print(s[2])
    print(s[6])
    ## output:
    ## l
    ## s
    

    Slicing in Python:

    Slicing # used to make sub-strings from strings used with start, end and step variable

    # s[start:end:step]
    s = "Hello World!"
    x = s[3:11]
    y =  s[:]
    z = s[:6]
    p = s[6:]
    print(x)
    print(y)
    print(z)
    print(p)
    print(s)
    ## output:
    ## lo World
    ## Hello World!
    ## Hello
    ## World!
    ## Hello World!
    

    Basic String Functions: –

    swapcase, upper, lower, strip, lstrip, rstrip, find, replace, format, center

    Swapcase:- used to change uppercase letters into lowercase letters and vice versa

    Upper:- It changes all letters into uppercase and returns the string

    Lower:- It changes all letters into lowercase and return the string

    Strip:- strip is used to remove all leading and trailing spaces from the string

    Lstrip:- It is used to remove left space

    Rstrip:- It is used to remove the right space

    Example to understand string functions:

    s = input("Enter a String : ")
    print(s)
    print("Swapcase : ",s.swapcase())
    print("Upper : ",s.upper())
    print("Lower : ",s.lower())
    print("Strip : ",s.strip())
    print("LStrip : ",s.lstrip())
    print("RStrip : ",s.rstrip())
    ## output:
    ## Enter a String : iclass gyansetu
    ## iclass gyansetu
    ## Swapcase :  ICLASS GYANSETU
    ## Upper :  ICLASS GYANSETU
    ## Lower :  iclass gyansetu
    ## Strip :  iclass gyansetu
    ## LStrip :  iclass gyansetu
    ## RStrip :  iclass gyansetu
    

    Lists

    Declaring a list:

    L = [1, "a" , "string" , 1+2]
    print(L)
    ## output : [1, 'a', 'string', 3]
    

    Homogeneous & Non-Homogeneous List

    Homogeneous List contains all elements of same data type.

    Non- Homogeneous List contains elements of different data type.

    l = [ 'hello','hi','how are you' ]
    print(l)
    print(l[2])
    l = [ 56,23,45,12,67,12,43,1,6,8,6,33,12]
    print("Homogeneous List :",l)
    print(l[5])
    l = [ 'hello','hi', 3, 4.5 ]
    print("Non-Homogeneous List : ",l)
    print(l[-3])
    ## output:
    ## ['hello', 'hi', 'how are you']
    ## how are you
    ## Homogeneous List : [56, 23, 45, 12, 67, 12, 43, 1, 6, 8, 6, 33, 12]
    ## 12
    ## Non-Homogeneous List :  ['hello', 'hi', 3, 4.5]
    ## hi
    

    Tuple

    Declaring a Tuple

    tup = 'python', 'gyansetu'
    print(tup)  
    ## output: ('python', 'gyansetu')
    
    ### Another way for doing the same
    tup = ('python', 'gyansetu')
    print(tup)
    ## output: ('python', 'gyansetu')
    

    Dictionary

    Dictionary Example with Key-Value pair

    mydict = {
        'name':'python',
        'build_year':1991,
        'Father of Python':"Guido Van Rossum",
        'Frame_works':['Django','Flask','Web2PY','Torando','kivi'],
        'versions' : [1.0,2.0,3.0],
        'latest_version':3.6}
    print(mydict)
    print("Name : ", mydict['name']) #returns the value of the key 'name'
    print("Frame Works : ", mydict['Frame_works'])
    ## output:
    ## {'name': 'python', 'build_year': 1991, 'Father of Python': 'Guido Van Rossum', 'Frame_works': ['Django', 'Flask', 'Web2PY', 'Torando', 'kivi'], 'versions': [1.0, 2.0, 3.0], 'latest_version': 3.6}
    ## Name :  python
    ## Frame Works :  ['Django', 'Flask', 'Web2PY', 'Torando', 'kivi']
    

    Operators in Python

    Arithmetic Operators

    Arithmetic operators are used to performing mathematical operations like addition, subtraction, multiplication and division

    1. Addition Operator ( + )
    2. Subtraction Operator ( – )
    3. Multiplication Operator ( * )
    4. Division Operator ( / )
    5. Modulas Operator ( % )
    6. Floor Division ( // )
    7. Exponent Operator ( ** )

    Example of Arithmetic Operator

    x = 10
    y = 3
    z1 = x+y
    z2 = x-y
    z3 = x * y
    print("Addition of {} and {} is {}.".format(x,y,z1))
    print("Subtraction of {} and {} is {}.".format(x,y,z2))
    print("Multiplication of {} and {} is {}.".format(x,y,z3))
    ## output:
    ## Addition of 10 and 3 is 13.
    ## Subtraction of 10 and 3 is 7.
    ## Multiplication of 10 and 3 is 30.
    

    Comparison Operators

    These operators compare the values on either side of them and decide the relation among them.

    1. Less Than ( < )
    2. Less Than Equals To ( <= )
    3. Greater Than ( > )
    4. Greater Than Equals To ( >= )
    5. Equals To Equals To ( == )
    6. Not Equals To ( != )

    Example of Comparison Operator

    #returns true if statement is True else returns False
    
    print("6 < 8 ", 6 < 8)               ## output: True
    print("6 <= 6 ", 6 <= 6)             ## output: True
    print("5 > 6 ", 5 > 6)               ## output: False
    print("6 != 7 ", 6 != 7)             ## output: True

    Logical Operators

    Logical operators are used on conditional statements (either True or False). They perform Logical AND, Logical OR, and Logical NOT operations

    1. And

    If x is false, return x

    else return y

    1. Or

    If x is false, return y

    else x

    Examples:

    print( 5>7 and 6-5*3+6)                   ## output: False
    print( 6-4*3+6 and 5>7)                   ## output: 0
    print( 6-4*3+6 or 6 > 5)                  ## output: True
    print( 6 > 5 or 6-4*3+6)                  ## output: True
    

    Membership Operator

    Membership operators are operators used to validate the membership of a value. It tests for membership in a sequence, such as strings, lists, or tuples.

    1. in
    2. not in

    Examples:

    s2 = "Dog is an animal."
    s1 = "Dog"
    x = s1 in s2
    if x :
        print("Pattern Found in step 1") #return this if x=True
    else :
        print("Patten Not Found")
    p = s1 not in s2
    print(x)
    print(p)
    ## OUTPUT:
    ## Pattern Found in step 1
    ## True
    ## False
    

    Identity Operator

    Python Membership and Identity Operators · in operator: The ‘in’ operator is used to check if a value exists in a sequence or not.

    1. is
    2. is not

    Examples:

    x = 5
    y = 5
    print(x is y)
    print( x is not y )
    p = 3
    q = 4
    if p is q :
        print("Both are equal")
    else :
        print("Both are different")
    

    Conditional Statements

    In programming and scripting languages, conditional statements or conditional constructs are used to perform different computations or actions depending on whether a condition evaluates to true or false. (Please note that true and false are always written as True and False in Python.)

    Example to calculate the greatest of 3 numbers using a conditional statement

    #Greatest among Three numbers
    a = int(input("A : "))
    b = int(input("B : "))
    c = int(input("C : "))
    if a >= b :
        if a >= c :
            print("A is greatest ")
        else :
            print("C is greatest ")
    elif b >= c :
        print("B is Greatest")
    else :
        print("C is Greatest ")
    ## OUTPUT:
    ## A : 12
    ## B : 32
    ## C : 16
    ## B is Greatest
    

    Loops in Python

    Loops can be divided into 2 kinds.

    There are 2 kinds of loops:

    For Loops: These loops are used to perform a certain set of statements for a given condition and continue until the condition has failed. You know the number of times that you need to execute the for a loop.

    Example of For loop

    print("List Iteration")
    l = ["books", "bags", "pens"]
    for i in l:
        print(i)
    ## OUTPUT:
    ## List Iteration
    ## books
    ## bags
    ## pens
    

    For loop using range()

    for i in range(5):
    print(i)
    ## OUTPUT:
    ## 0
    ## 1
    ## 2
    ## 3
    ## 4
    

    If you want to explore and learn coding skills in Python, then Gyansetu provides you the best platform to learn the Python language. Call:-  8130799520.