#!/usr/bin/env python3
"""
01_demo_basics.py — Thursday live demo: first steps with pandas.

IELE756 · Week 0 · March 5, 2026
Run in Google Colab or any Python 3.9+ environment.
"""

import pandas as pd

# ── 1. Hello world ──
print("Hello, IELE756!")
print(f"pandas version: {pd.__version__}")

# ── 2. Create a tiny DataFrame ──
data = {
    "nombre": ["Ana", "Boris", "Camila", "Diego", "Elena"],
    "edad": [28, 35, 42, 19, 55],
    "nacionalidad": ["Chilena", "Venezolana", "Chilena", "Haitiana", "Chilena"],
    "comuna": ["Iquique", "Alto Hospicio", "Iquique", "Alto Hospicio", "Pozo Almonte"],
}
df = pd.DataFrame(data)

print("\n── Shape ──")
print("Shape:", df.shape)

print("\n── DataFrame ──")
print(df)

# ── 3. value_counts ──
print("\n── Nationality counts ──")
print(df["nacionalidad"].value_counts())

# ── 4. Boolean filter ──
print("\n── Foreign-born only ──")
extranjeros = df[df["nacionalidad"] != "Chilena"]
print(extranjeros)