ee8d661058
### What changes were proposed in this pull request?
This PR proposes to move pandas related functionalities into pandas package. Namely:
```bash
pyspark/sql/pandas
├── __init__.py
├── conversion.py # Conversion between pandas <> PySpark DataFrames
├── functions.py # pandas_udf
├── group_ops.py # Grouped UDF / Cogrouped UDF + groupby.apply, groupby.cogroup.apply
├── map_ops.py # Map Iter UDF + mapInPandas
├── serializers.py # pandas <> PyArrow serializers
├── types.py # Type utils between pandas <> PyArrow
└── utils.py # Version requirement checks
```
In order to separately locate `groupby.apply`, `groupby.cogroup.apply`, `mapInPandas`, `toPandas`, and `createDataFrame(pdf)` under `pandas` sub-package, I had to use a mix-in approach which Scala side uses often by `trait`, and also pandas itself uses this approach (see `IndexOpsMixin` as an example) to group related functionalities. Currently, you can think it's like Scala's self typed trait. See the structure below:
```python
class PandasMapOpsMixin(object):
def mapInPandas(self, ...):
...
return ...
# other Pandas <> PySpark APIs
```
```python
class DataFrame(PandasMapOpsMixin):
# other DataFrame APIs equivalent to Scala side.
```
Yes, This is a big PR but they are mostly just moving around except one case `createDataFrame` which I had to split the methods.
### Why are the changes needed?
There are pandas functionalities here and there and I myself gets lost where it was. Also, when you have to make a change commonly for all of pandas related features, it's almost impossible now.
Also, after this change, `DataFrame` and `SparkSession` become more consistent with Scala side since pandas is specific to Python, and this change separates pandas-specific APIs away from `DataFrame` or `SparkSession`.
### Does this PR introduce any user-facing change?
No.
### How was this patch tested?
Existing tests should cover. Also, I manually built the PySpark API documentation and checked.
Closes #27109 from HyukjinKwon/pandas-refactoring.
Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
61 lines
2.6 KiB
Python
61 lines
2.6 KiB
Python
#
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# Licensed to the Apache Software Foundation (ASF) under one or more
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# contributor license agreements. See the NOTICE file distributed with
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# this work for additional information regarding copyright ownership.
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# The ASF licenses this file to You under the Apache License, Version 2.0
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# (the "License"); you may not use this file except in compliance with
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# the License. You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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def require_minimum_pandas_version():
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""" Raise ImportError if minimum version of Pandas is not installed
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"""
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# TODO(HyukjinKwon): Relocate and deduplicate the version specification.
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minimum_pandas_version = "0.23.2"
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from distutils.version import LooseVersion
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try:
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import pandas
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have_pandas = True
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except ImportError:
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have_pandas = False
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if not have_pandas:
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raise ImportError("Pandas >= %s must be installed; however, "
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"it was not found." % minimum_pandas_version)
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if LooseVersion(pandas.__version__) < LooseVersion(minimum_pandas_version):
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raise ImportError("Pandas >= %s must be installed; however, "
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"your version was %s." % (minimum_pandas_version, pandas.__version__))
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def require_minimum_pyarrow_version():
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""" Raise ImportError if minimum version of pyarrow is not installed
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"""
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# TODO(HyukjinKwon): Relocate and deduplicate the version specification.
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minimum_pyarrow_version = "0.15.1"
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from distutils.version import LooseVersion
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import os
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try:
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import pyarrow
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have_arrow = True
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except ImportError:
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have_arrow = False
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if not have_arrow:
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raise ImportError("PyArrow >= %s must be installed; however, "
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"it was not found." % minimum_pyarrow_version)
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if LooseVersion(pyarrow.__version__) < LooseVersion(minimum_pyarrow_version):
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raise ImportError("PyArrow >= %s must be installed; however, "
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"your version was %s." % (minimum_pyarrow_version, pyarrow.__version__))
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if os.environ.get("ARROW_PRE_0_15_IPC_FORMAT", "0") == "1":
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raise RuntimeError("Arrow legacy IPC format is not supported in PySpark, "
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"please unset ARROW_PRE_0_15_IPC_FORMAT")
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