AssertionError: col should be Column

问题

How to create a new column in PySpark and fill this column with the date of today?

This is what I tried:

import datetime
now = datetime.datetime.now()
df = df.withColumn("date", str(now)[:10])

I get this error:

AssertionError: col should be Column

回答1:

How to create a new column in PySpark and fill this column with the date of today?

There is already function for that:

from pyspark.sql.functions import current_date

df.withColumn("date", current_date().cast("string"))

AssertionError: col should be Column

Use literal

from pyspark.sql.functions import lit

df.withColumn("date", lit(str(now)[:10]))

来源：https://stackoverflow.com/questions/47903905/assertionerror-col-should-be-column