Python 断言错误：col 应该是 Column
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AssertionError: col should be Column
提问by Markus
How to create a new column in PySpark and fill this column with the date of today?
如何在 PySpark 中创建一个新列并用今天的日期填充此列？
This is what I tried:
这是我尝试过的：
import datetime
now = datetime.datetime.now()
df = df.withColumn("date", str(now)[:10])
I get this error:
我收到此错误：
AssertionError: col should be Column
断言错误：col 应该是 Column
回答by Alper t. Turker
How to create a new column in PySpark and fill this column with the date of today?
如何在 PySpark 中创建一个新列并用今天的日期填充此列？
There is already function for that:
已经有这样的功能：
from pyspark.sql.functions import current_date
df.withColumn("date", current_date().cast("string"))
AssertionError: col should be Column
断言错误：col 应该是 Column
Use literal
使用文字
from pyspark.sql.functions import lit
df.withColumn("date", lit(str(now)[:10]))
