Read NDJSON / JSON Lines Files

import pandas as pd

# Read NDJSON (one JSON object per line)
df = pd.read_json('events.ndjson', lines=True)

# Streaming (for large files)
chunks = pd.read_json('large_events.ndjson', lines=True, chunksize=50_000)
results = []
for chunk in chunks:
    chunk = chunk[chunk['action'] == 'purchase']
    results.append(chunk)

filtered = pd.concat(results, ignore_index=True)
print(f'Purchase events: {len(filtered):,}')