Skip to main content
PYSPARK • LESSON 155

Grouped Map Pandas UDF Concepts

How do we define a grouped normalization function operating over partition DataFrames in Pandas?

Expert2 Minutes840 XP
🤔 THE QUESTION

How do we define a grouped normalization function operating over partition DataFrames in Pandas?

💡 WHAT IS IT?

Applying a Pandas DataFrame transformation across groups using groupby().applyInPandas().

🎯 WHAT IS IT USED FOR?

Per-group statistical normalization, localized time-series ARIMA fitting, and group-wise ML modeling.

💻 EXAMPLE
import pandas as pd
from pyspark.sql.functions import pandas_udf

def normalize_group(pdf: pd.DataFrame) -> pd.DataFrame:
    pdf["score"] = (pdf["score"] - pdf["score"].mean()) / pdf["score"].std()
    return pdf

🎯 Mission Objectives

Practice typing production-grade PySpark code for Grouped Map Pandas UDF Concepts.

  • Define group-wise Pandas transformation
  • Compute z-score normalization in Pandas
  • Prepare function for applyInPandas