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Code Keys/PySpark Academy/Module 15/Lesson 116
PYSPARK • LESSON 116

First Event Value in Window with first()

How do we identify the original marketing attribution channel that first brought a user to our platform?

Advanced⏱ 2 Minutes⭐ 650 XP
🤔 THE QUESTION

How do we identify the original marketing attribution channel that first brought a user to our platform?

💡 WHAT IS IT?

first(col).over(windowSpec) returns the earliest value in an ordered window partition.

🎯 WHAT IS IT USED FOR?

First-touch marketing attribution, initial landing page identification, and cohort origin tracking.

💻 EXAMPLE
from pyspark.sql.window import Window
from pyspark.sql.functions import col, first

window_spec = Window.partitionBy("user_id").orderBy("event_timestamp")
df = df.withColumn("first_event", first(col("event_type")).over(window_spec))

🎯 Mission Objectives

Practice typing production-grade PySpark code for First Event Value in Window with first().

  • ✓ Import first window function
  • ✓ Retrieve initial event type in chronological session
  • ✓ Enable first-touch user attribution
🚀 Start Mission
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