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PYSPARK โ€ข LESSON 215

Schema Validation & Cast Safety

How can we safely cast string numbers to integers and isolate corrupted alphanumeric strings?

Advancedโฑ 3 Minutesโญ 840 XP
๐Ÿค” THE QUESTION

How can we safely cast string numbers to integers and isolate corrupted alphanumeric strings?

๐Ÿ’ก WHAT IS IT?

Casting a non-numeric string to numeric produces null, which can be detected to separate valid rows from corrupted rows.

๐ŸŽฏ WHAT IS IT USED FOR?

Parsing unvalidated CSV columns into structured types with guaranteed cast safety.

๐Ÿ’ป EXAMPLE
df_cast = df.withColumn("numeric_val", col("raw_val").cast("double"))
df_corrupted = df_cast.filter(col("raw_val").isNotNull() & col("numeric_val").isNull())

๐ŸŽฏ Mission Objectives

Practice typing production-grade PySpark code for Schema Validation & Cast Safety.

  • โœ“ Safe type casting
  • โœ“ Corrupted string detection
  • โœ“ Schema compliance check