Data Science ยท Chapter 4 of 43
Data Collection
Data comes from DATABASES (SQL), APIs (REST/GraphQL), FILES (CSV/Excel), WEB SCRAPING and SENSORS/LOGS.
Document the source, license and refresh cadence for every dataset you use.
Example 1 (python)
import pandas as pd
df = pd.read_csv('sales.csv')
print(df.head())Read a CSV file.
Example 2 (python)
import requests
r = requests.get('https://api.example.com/users')
data = r.json()Pull from a REST API.
Key points
- Sources: DB, API, files, scraping, sensors.
- Always record where data came from.
- Check licence and privacy rules.
- Refresh cadence matters for freshness.
๐ก Note: Save the raw file untouched โ do all cleaning downstream so you can always re-do the pipeline.