Pandas & NumPy Data & Arrays
Fast Operations

Pandas & NumPy for ML

Pandas and NumPy provide the foundation for data manipulation and numerical computing in Machine Learning workflows.

NumPy Array Basics

Creating and reshaping arrays
import numpy as np

a = np.array([1, 2, 3])
matrix = np.arange(12).reshape(3, 4)

print(matrix.shape)   # (3, 4)
print(matrix.mean(axis=0))

Pandas DataFrames

Loading and inspecting data
import pandas as pd

df = pd.read_csv("data.csv")

print(df.head())
print(df.info())
print(df.describe())

Grouping & Aggregation

grouped = df.groupby("category")["sales"].agg(["mean", "sum", "count"])
print(grouped)

Joins & Merges

merged = df_customers.merge(df_orders, on="customer_id", how="inner")