pyspark.sql.functions.assert_true

pyspark.sql.functions.assert_true(col: ColumnOrName, errMsg: Union[pyspark.sql.column.Column, str, None] = None) → pyspark.sql.column.Column

Returns null if the input column is true; throws an exception with the provided error message otherwise.

Parameters
colColumn or str

column name or column that represents the input column to test

errMsgColumn or str

A Python string literal or column containing the error message

Examples

>>> df = spark.createDataFrame([(0,1)], ['a', 'b'])
>>> df.select(assert_true(df.a < df.b).alias('r')).collect()
[Row(r=None)]
>>> df = spark.createDataFrame([(0,1)], ['a', 'b'])
>>> df.select(assert_true(df.a < df.b, df.a).alias('r')).collect()
[Row(r=None)]
>>> df = spark.createDataFrame([(0,1)], ['a', 'b'])
>>> df.select(assert_true(df.a < df.b, 'error').alias('r')).collect()
[Row(r=None)]