import numpy as np

arr = np.array([1, 2, 3, 4, 5])

print(arr)

zeros_array = np.zeros((3, 4))   3x4 Array with zeroes

ones_array = np.ones((2, 2))     2x2 Array with ones

range_array = np.arange(0, 10, 2)   Output: [0 2 4 6 8]

arr1=np.array([1,2,3])

arr2=np.array([4,5,6])

sum_array = arr1 + arr2  Array adding the two arrays element wise

print(sum_array)

product_array = arr1 * arr2  Multiplication of two arrays

print(product_array)

sin_array = np.sin(arr1)  Each element has a sine function applied to it

log_array = np.log(arr1)  Apply the natural logarithm

arr2D = np.array([[1, 2, 3],[4, 5, 6]])

print(arr2D)

element = arr2D[1, 2] Selecting the 2nd row, 3rd column element

print(element)

subarray = arr2D[0:1, 1:3] Copies elements of first row, 2nd to 3rd column

print(subarray)

arr1D = np.array([1, 2, 3, 4, 5, 6])

arr2D = arr1D.reshape((2, 3))   Two dimensional array of two rows and three columns

print(arr2D)

arr2D = np.array([[1, 2], [3, 4]])

result = arr2D + 5   Add 5 to every element in the array

print(result)

Math Operations Module Example

def add(a, b):
    return a + b;
def subtract(a, b):
    return a - b;

Main Program Example

import math_operations
result = math_operations.add(5, 3)
print(result)  Output: 8

Module Import Example

import math_operations
result = math_operations.subtract(10, 5)

Specific Function Import Example

from math_operations import add
result = add(3, 4)

Alias Import Example

import math_operations as math_ops
result = math_ops.add(7, 8)

DateTime Module Example

import datetime
current_time = datetime.datetime.now()
print(current_time)

Package Installation Example

pip install requests

Requests Module Example

import requests
response = requests.get("https://www.example.com")
print(response.text)

Virtual Environment Creation Example

python3 -m venv myenv

Virtual Environment Activation Example

source myenv/bin/activate   On macOS/Linux
myenvScriptsactivate   On Windows
pip install requests

Class Definition Example

def __init__(self, name, age):
    self.name = name
    self.age = age
 function that rudimentary implements the characteristics of a dog 
def speak(self):    
return f"{self.name} says woof!"

Object Creation Example

dog1 = Dog("Buddy", 3)
print(dog1.name)   Output: Buddy
print(dog1.speak())  Output: Buddy says woof.

Class and Instance Variables Example

class Dog:
    species = "Canine"   Class variable
 
    def __init__(self, name, age):
        self.name = name   Instance variable
        self.age = age     Instance variable

Inheritance Example

class Animal:
    def __init__(self, name):
        self.name = name
    def speak(self):
        return f"{self.name} makes a sound."

class Dog(Animal):   Dog is a subclass of Animal
    def speak(self):   Overriding the speak method
        return f"{self.name} barks."

class Cat(Animal):   Cat is a subclass of Animal
    def speak(self):   Overriding the speak method
        return f"{self.name} meows."

Encapsulation Example

class BankAccount:
    def __init__(self, owner: str, balance):
        self.owner = owner
        self.__balance = balance   Private variable    

    def deposit(self, amount):
        if amount > 0:
            self.__balance += amount 

    def withdraw(self, amount):
        if amount > 0 and amount <= self.__balance:
            self.__balance -= amount

        def get_balance(self):
        return self.__balance

Basic Exception Handling Example

try:
     This code could potentially lead to an Exception 
    risky_code ( )
except ExceptionType:
    print("An error occurred.")
else:   
    print("Did something go wrong?")

Specific Exception Handling Example

try:
    a = 1
    5/0
except NameError:
    print('Exception occurred')

Finally Block Example

try:
    a = 0
    if a == 0:
        raise ZeroDivisionError("Division by zero")
    else:
        2/a
except ZeroDivisionError:
    print ('error is raised')
finally:
    print ('Don't divide a number by zero')

PDB Debugger Example

import pdb; pdb.set_trace()

Logging Example

import logging
  
 Setting up the logging configuration
logging.basicConfig(level=logging.DEBUG)

 Logging a debug message
logging.debug("This is a debug message.")

 Logging an info message
logging.info("This is an info message.")

File Reading with Context Manager Example

with open('example.txt', 'r') as file:
    content = file.read()
    print(content)

File Error Handling Example

try:
    with open('example.txt', 'r') as file:
        content = file.read()
        print(content)
except FileNotFoundError:
    print("The file does not exist.")

List Manipulation Example

fruits = ['apple', 'banana', 'cherry']
fruits.append('orange')   Adds 'orange' to the end of the list
fruits[1] = 'blueberry'   Changes 'banana' to 'blueberry'

Tuple Example

colors = ('red', 'green', 'blue')

Tuple Immutability Example

colors[1] = 'yellow'  This will cause an error since the tuples have been assigned and are thus immutable

Dictionary Example

person = {'name': 'John', 'age': 30, 'city': 'New York'}
print(person['name'])   Output will be 'John'

Dictionary Modification Example

person['age'] = 31  Sets the value of age to 31
person['job'] = 'Engineer'  Sets the job for the person as a key-value pair

Dictionary Deletion Example

del person['city']   The key city and its value are removed

Function Structure

def function_name(parameter1, parameter2, …):
 Code block that performs an operation
 On the parameters
return result
}

Addition Function Example

def add_numbers(a, b):
    return a + b  This is called the function.

 Invoking the function with an argument
result= add_numbers(5, 3)
print(f'the result is: {result}')  The output is logically expected to be equal to 8

Global Variable Example

x = 10   Variable which is Global

def print_global():
    print(x)   Global variable is being Accessed Inside A Function

print_global()  Result will be 10

Local Variable Example

def add_two_numbers(a: int, b: int) -> int:
    sum_result: int = a + b  
    return sum_result

Global Variable Modification Example

x = 10
def global_x_addition():
    global x
    x = 20
global_x_addition()
print(x)

Basic If Statement Syntax

if condition:
   //code block to be executed if that condition turns to be True

Voting Age Example

age = 20;
if age >= 18:
    print("You are eligible to vote")

Number Check Example

number = -5
if number >= 0:
    print("the number is positive")
else:
    print("the number is negative")

Grade Evaluation Example

score = 85
if score >= 90:
    print("Grade: A")
elif score >= 80:
    print("Grade: B")
elif score >= 70:
    print("Grade: C")
else:
    print("Grade: F")

For Loop Syntax

for item in sequence:
     Code block to execute for each item

For Loop Example

fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
    print(fruit)

While Loop Syntax

while expression:
    code which is carried out provided the expression evaluates to True

While Loop Example

count = 1
while count <= 5:
    print(count)
    count += 1

Assign Variable

age = 25

Integer Variable

count = 10

Float Variable

height = 5.9

String Variable

name = "Alice"

Boolean Variable

is_sunny = True

List Variable

fruits = ["apple", "banana", "cherry"]

Dictionary Variable

person = {"name": "Alice", "age": 25}

Tuple Variable

coordinates = (10, 20)

Arithmetic Operators

+   (Addition)
–   (Subtraction)
 (Multiplication)
/ (Division)
// (Floor Division)
%   (Modulus)
   (Exponentiation)

Arithmetic Operators

a = 5
b = 3
print(a + b) # Output: 8

Arithmetic Operators

== (Equal to)
!= (Not equal to)
> (Greater than)
< (Less than)
>= (Greater than or equal to)
<= (Less than or equal to)

Comparison Operators

x = 10
y = 5
print(x > y) # Output: True

Logical Operators

print(x < 10 and y > 5)   # Output: True

Assignment Operators

x=5
x +=3  # Creates the value of x at 8

Membership Operator

fruits = [ "apple", "banana", "cherry"]
print( "banana" in fruits )  # Output: true

Install Package

pip install 

Install NumPy

pip install numpy

Import NumPy

import numpy as np

Create Virtual Environment

python -m venv venv

Activate Virtual Environment (Windows)

venvScriptsactivate

Activate Virtual Environment (macOS/Linux)

source venv/bin/activate

Deactivate Virtual Environment

deactivate