[SPARK-36333] Reuse isnull where the null check is needed.

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.2.0
• Fix Version/s: 3.2.0
• Component/s: PySpark
• Assignee: Takuya Ueshin
• Reporter: Takuya Ueshin
• Created: 28/Jul/21 23:14
• Updated: 29/Jul/21 22:34
• Resolved: 29/Jul/21 22:34

Description

There are some places where we can reuse isnull instead of directly using Spark Column.

Issue Links

• relates to: SPARK-34849 SPIP: Support pandas API layer on PySpark
• links to: [Github] Pull Request #33562 (ueshin)
• links to: [Github] Pull Request #33562 (ueshin)