pyspark.sql.functions.transform_keys

pyspark.sql.functions.transform_keys(col: ColumnOrName, f: Callable[[pyspark.sql.column.Column, pyspark.sql.column.Column], pyspark.sql.column.Column]) → pyspark.sql.column.Column

Applies a function to every key-value pair in a map and returns a map with the results of those applications as the new keys for the pairs.

New in version 3.1.0.

Changed in version 3.4.0: Supports Spark Connect.

Parameters

colColumn or str

name of column or expression

ffunction

a binary function (k: Column, v: Column) -> Column... Can use methods of Column, functions defined in pyspark.sql.functions and Scala UserDefinedFunctions. Python UserDefinedFunctions are not supported (SPARK-27052).

Returns

Column

a new map of enties where new keys were calculated by applying given function to each key value argument.

Examples

>>> df = spark.createDataFrame([(1, {"foo": -2.0, "bar": 2.0})], ("id", "data"))
>>> row = df.select(transform_keys(
...     "data", lambda k, _: upper(k)).alias("data_upper")
... ).head()
>>> sorted(row["data_upper"].items())
[('BAR', 2.0), ('FOO', -2.0)]

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