DataFrames: Tabular Data in Pandas

DataFrames Basics

A DataFrame is a 2‑dimensional labeled data structure with columns of potentially different types.

Creating DataFrames

import pandas as pd

# From a dict of lists
df = pd.DataFrame({
    "city": ["NY", "LA", "SF"],
    "population": [8.4, 4.0, 0.9],
    "area": [783, 1214, 600]
})
print(df)

Inspecting DataFrames

print(df.head())    # first 5 rows
print(df.info())    # summary
print(df.describe())   # numeric stats

Selecting columns

pop = df["population"]
print(pop)

Adding a new column

df["density"] = df["population"] / df["area"]
print(df)