NumPy Complete Guide 📊🐍

Core Library for Data Science & AI

1. What is NumPy?

NumPy is a Python library used for working with arrays, matrices, and mathematical operations.

2. Installation

pip install numpy

3. Creating Arrays

import numpy as np

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

4. 2D Arrays (Matrix)

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

print(matrix)

5. Array Operations

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

print(a + b)
print(a * b)

6. NumPy Functions

np.zeros(5)   # [0,0,0,0,0]
np.ones(3)    # [1,1,1]
np.arange(10) # 0 to 9

7. Statistics

arr = np.array([10, 20, 30])

print(np.mean(arr))
print(np.sum(arr))
print(np.max(arr))

8. Indexing

arr = np.array([10, 20, 30])

print(arr[0])  # 10
print(arr[2])  # 30

9. Real Use Cases