BigData / Apache Parquet Interview Questions
How do you read and write Parquet files in Python with PyArrow?
PyArrow provides a low-level Parquet library that is fast, pure Python-friendly, and interoperates with Pandas:
Write:
import pyarrow as pa
import pyarrow.parquet as pq
table = pa.Table.from_pandas(df)
pq.write_table(table, "output.parquet", compression="zstd")
Read:
table = pq.read_table("output.parquet")
df = table.to_pandas()
Read specific columns only (column pruning):
table = pq.read_table("output.parquet", columns=["user_id", "revenue"])
Read with filter pushdown:
import pyarrow.dataset as ds
dataset = ds.dataset("s3://bucket/data/", format="parquet")
table = dataset.to_table(
columns=["user_id", "revenue"],
filter=ds.field("date") == "2026-01-01"
)
PyArrow's dataset API supports partitioned directories and applies filter pushdown automatically using Parquet statistics.
Invest now in Acorns!!! 🚀
Join Acorns and get your $5 bonus!
Acorns is a micro-investing app that automatically invests your "spare change" from daily purchases into diversified, expert-built portfolios of ETFs. It is designed for beginners, allowing you to start investing with as little as $5. The service automates saving and investing. Disclosure: I may receive a referral bonus.
Invest now!!! Get Free equity stock (US, UK only)!
Use Robinhood app to invest in stocks. It is safe and secure. Use the Referral link to claim your free stock when you sign up!.
The Robinhood app makes it easy to trade stocks, crypto and more.
Webull! Receive free stock by signing up using the link: Webull signup.
More Related questions...
