datafusion-python/examples/python-udf.py at main · nirnayroy/datafusion-python · GitHub

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# Licensed to the Apache Software Foundation (ASF) under one

# or more contributor license agreements. See the NOTICE file

# distributed with this work for additional information

# regarding copyright ownership. The ASF licenses this file

# to you under the Apache License, Version 2.0 (the

# "License"); you may not use this file except in compliance

# with the License. You may obtain a copy of the License at

# http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing,

# software distributed under the License is distributed on an

# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

# KIND, either express or implied. See the License for the

# specific language governing permissions and limitations

# under the License.

import pyarrow

from datafusion import SessionContext, udf

from datafusion import functions as f

def is_null(array: pyarrow.Array) -> pyarrow.Array:

return array.is_null()

is_null_arr = udf(is_null, [pyarrow.int64()], pyarrow.bool_(), "stable")

# create a context

ctx = SessionContext()

# create a RecordBatch and a new DataFrame from it

batch = pyarrow.RecordBatch.from_arrays(

[pyarrow.array([1, 2, 3]), pyarrow.array([4, 5, 6])],

names=["a", "b"],

)

df = ctx.create_dataframe([[batch]])

df = df.select(is_null_arr(f.col("a")))

result = df.collect()[0]

assert result.column(0) == pyarrow.array([False] * 3)

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