Just imagine, you'd like to,

• Manipulate data: Operators enable you to perform calculations, comparisons, and assignments, like "calculate the 5 power 7 ? ".

• Make decisions: If-else conditions let your program make choices based on data, like "if it's raining, take an umbrella".

• Repeat tasks: Loops help you perform actions multiple times, like "printing I love you 5 times".

Mastering these fundamentals concept will help you write efficient, logical, and readable code, to become a good Python programmer!

Operators

In python, operators are special symbols or keywords which are used to perform operations on variables and values. Let's learn different types of operators in python,

1. Arithmetic Operators

   We used arithmetic operators for basic mathematical operations like,

   • + : Addition

   • - : Subtraction

   • * : Multiplication

   • / : Division

   • % : Modulus (remainder of division)

   • ** : Exponentiation (power of)

   • // : Integer Division (returns, the nearest integer lower than the result)

       print(5+6)     # 11 
       print(5-6)     # -1    
       print(5*6)     # 30    
       print(5/2)     # 2.5   
       print(5//2)    # 2    
       print(5%2)     # 1     
       print(5**2)    # 25
     

2. Relational Operators

   We used relational operators to compare two values and return result in boolean.

   • == : Equal to

   • != : Not equal to

   • > : Greater than

   • < : Less than

   • >= : Greater than or equal to

   • <= : Less than or equal to

       print(4>5)     # False
       print(4<5)     # True
       print(4>=5)    # True
       print(4<=5)    # True
       print(4==4)    # True
       print(4!=4)    # False
     

3. Logical Operators

   Logical operators are used to combine conditional statements.

   • and : Returns True if both statements are true

   • or : Returns True if one of the statements is true

   • not : If True return False | If False return True

       print(1 and 0)    # O [False]
       print(0 or 1)     # 1 [True]
       print(not 1)      # False
     

4. Bitwise Operators

   We use bitwise operators only to operate on bits or binary digits.

   • & : AND

   • | : OR

   • ^ : XOR (exclusive OR)

   • ~ : NOT (inverts all the bits)

   • << : Left shift

   • >> : Right shift

       print(2&3)    # 2
       print(2|3)    # 3
       print(2^3)    # 1
       print(~3)     #-4
       print(4>>2)   # 1
       print(5<<2)   # 20
     

In data science, bitwise operators are not commonly used may be we used & (AND) ,| (OR) operators for image processing , computer vision projects. But, typically more relevant in low-level programming, system programming. To understand more : Link

5. Assignment Operators

   Assignment operators = is used to assign a value to a variable.

    a = 2 # assign value 2 to variable a
   
    a += 2 # means: a = a + 2
    print(a) # 4
   

6. Identity Operators

   Identity operators are used to check if two values are located at same memory location or not.

   • is : True if the operands are identical (refer to the same object)

   • is not : True if the operands are not identical (do not refer to the same object)

       a = 10
       b = 10
       c = a
       l1 = [1,2,3]
       l2 = [1,2,3]
     
       print(a is b)    # True
       print(a is c)    # True
       print(c is b)    # True
       print(l1 is l2)  # False
     

Here, l1 and l2 have same list but they are not identical because it store both in different memory location although they have same list.

7. Membership Operators

   Membership operators are used to check if a sequence is presented in or not.

   • in : True if value found in a sequence

   • not in : True if value not found in a sequence

       print('P' in 'Python')        # True
       print('P' in 'python')        # False
       print(1 not in [1,2,3,4,5])   # False
     

Now that you've learned the basics of operators in Python, it's time to put that knowledge into practice.

Task:WAP to find the sum of 3 digits number given by the user. Eg. Input: 345 | Output: 12

If-Else Condition

In Python, if-else statements are essential control flow tools that enable you to make decisions based on specific conditions. Here’s a simple example to understanding if-else statements in Python.

age = 15
if age >= 18:
    print("You are eligible for driving license")
else:
    print("You are a minor.")

# Output: You are a minor.

Here, if-else statement allows you to execute one block of code if the condition is True and another block of code if the condition is False. Since age is 15, the condition age >= 18 is False, so the message "You are a minor." is printed.

Moreover, for more complex decision-making, we use elif ("else if") to check multiple conditions. It lets you test several conditions in sequence until one is found to be true. Here's a simple login program to check whether the user input email and password are valid or not.

# valid_email -> datadiary@gmail.com
# password -> datadiary
email = input('enter email: ')
password = input('enter password: ')

if email == 'datadiary@gmail.com' and password == 'datadiary':
  print('Welcome')
# if email valid but password  wrong
elif email == 'datadiary@gmail.com' and password != 'datadiary':
  # tell the user
  print('Incorrect password')
    # Reenter password
  password = input('enter password again: ')
  if password == 'datadiary':
    print('Welcome,finally!')
  else:
    print('password invalid')
else:
  print('No correct input.')

Now, try to solve one question on if-else statement,

Task :WAP that determines the category of a person based on their given age.

• "Child" if the age is 0-12

• "Teenager" if the age is 13-19

• "Adult" if the age is 20-59

• "Senior" if the age is 60 or above

Modules

Python Module is a file that contains built-in functions, classes, and variables. There are many Python modules, each with its specific work. In this section, we are going to learn about math, keywords, random and datetime modules. To know more about python modules you can check on python documentation page.

1. Math

   The math module provides access to a variety of mathematical functions and constants.

   • math.sqrt(x): Returns the square root of x.

   • math.pow(x, y): Returns x raised to the power of y.

   • math.pi: The constant π (pi).

   • math.sin(x), math.cos(x), math.tan(x): Trigonometric functions.

   • math.log(x, base): Returns the logarithm of x to the specified base.

       import math
       print(math.sqrt(190)     # 13.784
       print("Value of pi:", math.pi) # 3.1416
     

2. Keywords

   Keyword module provides a simple way to check for Python keywords, which are reserved words that cannot be used as identifiers (variable names, function name etc.

    import keyword
    print('Total keyword in python: ', len(keyword.kwlist)) # 35
    print(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']
   

3. Random

   The random module is used to generate random numbers and perform random operations. It is useful for tasks like simulations, gaming, and random sampling.

   • random.random(): Returns a random float between 0.0 and 1.0.

   • random.randint(a, b): Returns a random integer between a and b (inclusive).

   • random.shuffle(seq): Shuffles the sequence seq in place.

       import random
       print(random.randint(1,100)) # 3
       numbers = [1,2,3,4,5]
       random.shuffle(numbers)
       print(numbers)     # [1,2,5,3,4]
     

4. Datetime

   The datetime module supplies classes for manipulating dates and times. It is useful for applications that require date and time calculations.

   • datetime.date(y, m, d): Represents a date.

   • datetime.time(hrs, min, sec): Represents a time.

   • datetime.datetime(year, month, day, hour, minute, second): Represents both date and time.

   • datetime.datetime.now(): Returns the current local date and time.

       import datetime
       print(datetime.datetime.now())
       # 2024-05-23 12:29:11.942735
     

Task:

1. Write a Python program that checks if a given word is a Python keyword.

2. Write a Python program that generates and prints a random password. The password should be 8 characters long and can include uppercase letters, lowercase letters, and digits.

Loops

Python provides two types of loops: for loops and while loops. In this section, we'll explore both types of loops,

1. For loop

   A for loop is used to iterate over a sequence (like a list, tuple, dictionary, set, or string) and execute a block of code for each item in the sequence.

     for i in range(1,2,3,4,5):
         print(i)
     # 1
     # 2
     # 3
     # 4
     # 5
    # range() is often used to generate a sequence of numbers.
   

2. While loop

   A while loop executes a block of code as long as a specified condition is true.

    i = 1
    while i <= 4:
        print(i)
        i += 1
    # 1 
    # 2
    # 3
    # 4
   

   Above, while loop continues to execute as long as i is less than or equal to 4. The value of i is incremented by 1 in each iteration until the condition is no longer satisfied.

Task:

1. Write a Python program that takes an integer n as input and prints the multiplication table for n up to 10.

2. The current population of a town is 10000. The population of the town is increasing at the rate of 10% per year. You have to write a program to find out the population at the end of each of the last 10 years.

If you have any questions on any topic covered in this blog post, feel free to leave a comment below. I'm here to help you on your learning journey!

Happy coding and happy learning! 🚀

1. Powerful Libraries: Tools like NumPy, Pandas, Matplotlib, and Scikit-Learn simplify data analysis, manipulation, visualization, and machine learning.

2. Community and Resources: A large, active community and abundant resources (tutorials, courses, documentation) provide ample learning support.

3. Versatility: Python integrates well with other technologies and is used across various fields, making it a flexible tool.

4. Industry Demand: Many top companies use Python for data science, enhancing job prospects and career opportunities.

1. Python Output

print('Hello World')
#Output: Hello World
print('Hello', 1, 4.5, True) # multiple item print
#Output: Hello 1 4.5 True
print('Hello', 1, 4.5, True, sep = '/') # each item seperated by /
#Output: Hello/1/4.5/True
print('Hello', end = '-') # Default newline 
print('World')
#Output: Hello-World

Remember, python is case-sensitive language means is Print() and print() are not same.

2. Data Type

   In every programming language data type are important, python has integer, float, boolean, string, complex, list, tuple, sets, dictionary.

# Integer 
print(8)
print(1e308) # handel till 1* 10 ^ 308 integers
#Float
print(23.3)
print(1.7e308) # handel till 1 * 10 ^ 308 floats
# Boolean 
# True | False
print(True)
# String
print('Hey I am a string')
# NOTE: Python doesn't have char dtype only string
# Complex
print(5+6j)

#Output:   
#   8
#   inf
#    23.3
#   inf
#  True
#    Hey I am a string
#   (5+6j)

# List
print([1,2,3,4,5])
# Tuple
print(12,13,14,15)
# Dictionary
print({Fruit: 'Apple', Name: 'Beta'}
# Set
print({1,2,3,4,5})

#Output: 
#   [1, 2, 3, 4, 5]
#   12 13 14 15
#   {'name': 'Ninja', 'gender': 'Male', 'weight': 60}
#   {1, 2, 3, 4, 5}

3. Variables

   Variables in python on the other hand, are like labeled containers that store any kind of information. For eg: You are a web developer and want to show login user name after s/he login-in successfully [ Hello, [var_name] ] for this, you just define a variable name and as user login in you pass that name to var_name . So, in simple term variables are container for future use.

    name = 'myName'
    print(name)
    # No need to explicitly declear dtype it automatically know
   
    a = 5
    b = 6
    print(a + b) # Output: 11
   
    # In python, variable don't need to declear at the top like C/ C++, 
    # as you need you declear it.
   

   ❓

   Interview Question:

   1. Difference between Dynamic vs Static Typing?

   - In dynamic, you explicitly tell data-type while declaring variable.

   Eg. int a = 5; [ C/ C++/ Java]

   - In static, you don't need to declare data-type, interpreter automatically know. Eg. a = 5

   ---

   2. Difference between Dynamic vs Static Binding?

   - In dynamic binding, variable you created doesn't have fixed data-type meaning we can change it's data-type as need.

   Eg. a = 5 | a = 'apple' ✅

   - In static binding, once you define a variable data-type then it's fixed you can't change its data-type.

   Eg. int num = 50 | string num = 'hello' ❌

   ---

4. Keywords and Identifiers

   Simply, keyword are the reserved word which are predefined in python and have special meanings to the compiler. We cannot use this 36 keywords as variable name, function name in python.

   

   Identifiers are the names given by programmer to variables, functions, classes. There are some rules we need to follow to create a valid identifiers.

• You can't start name with a digit. 1name = 'myName' ❌

• You cannot use any special character except underscore _

  first_name = 'John' ✅

  Any other than underscore_are not valid to create an identifiers.

• Identifiers cannot be keywords

5. User Input

   Taking input from user is important as a programmer. There are two type of software: static and dynamic software. Static software are those software which do not interact with user (only provide information). For eg: clock, calendar, a blog, college website (mostly static). Dynamic software is where user interact with software (input). For eg: Youtube, booking ride, placing food order and so on. In today's world, almost 90 % of software are dynamic software.

   To make, such dynamic software, we need to take input from the user first.

# Taking input from user and store in user_name variable
user_name = input("Enter your name:")
print("Hello, {0}! How are you?".format(user_name))

# Output: 
# Enter your name: rajesh
# Hello, rajesh! How are you?

Task :Write a program to take 2 numbers from user and print sum of two numbers.

6. Type Conversion

   In python, we have two type conversion, implicit and explicit. In implicit type conversion, compiler internally convert the type with programmer interaction. But, implicit doesn't work all the time. Whereas, explicit type conversion, programmer change the type of data manually.

# Implicit
print(5+6.6)        # 11.6
print(type(5),type(5.6))     # <class 'int'> <class 'float'>   
## Python automatically convert the type but may not work always.

print(4 + '4')     # Error

# Explicit
# string to integer
type(int('4'))    # int
int(4.5)     # 4
int(4+5j)    # Error [can't convert complex to integer]
#### So, type conversion only work when possible.

str(5)     # '5'
float(6)     # 6.0

7. Literals

   Literals are the raw values that you store in variable. There are many way to set literals in python we will look on them one by one.

   

    a = 0b1010 # Binary Literals
    b = 100 # Decimal Literal
    c = 0o310 # Octal Literal
    d = 0x12c # Hexadecimal Literal
   
    # Float Literal
    float_1 = 10.5
    float_2 = 1.5e2 # 1.5 * 10^2
    float_3 = 1.5e-3 # 1.5 * 10^-3
   
    # Complex Literal
    x = 3.14j
   
    print(a, b, c, d) # 10 100 200 300
    print(float_1, float_2,float_3) # 10.5 150.0 0.0015
    print(x, x.imag, x.real) # 3.14j 3.14 0.0
   

   Moreover, in python we can store unicode (emojis) and raw strings.

unicode = u"\U0001f600\U0001F606\U0001F923"
raw_str = r"raw \n string"

print(unicode)    # 😀😆🤣
print(raw_str)    # raw \n string

# In python, boolean True (1) and False (0) treated as a number
# So, we can do as follows,

a = True + 4
b = False + 10

print(a)    # 5
print(b)    # 10

None Literals

In python like other programming we cannot declare variable beforehand. To do so, we can used None (a variable with no value).

k # error can't do
a = None # use None to clear no value variable
print(a) # None

8. Practice Question

   1. WAP that will convert celsius value to Fahrenheit.

   2. WAP to take 2 numbers from user and swap them without using any special python syntax.

   3. WAP to find the sum of squares of first n natural numbers where n will be provided by the user.

   4. Given the first 2 terms of an Arithmetic Series. Find the Nth term of the series. Just assume all inputs are provided by user.

Happy Coding! 🧑🏻‍💻