### What changes were proposed in this pull request?
This is a backport of #33377.
Revisit and manage `InternalField` in more places.
### Why are the changes needed?
There are other places we can manage `InternalField`, and we can keep extension dtypes or `CategoricalDtype`.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Added some tests.
Closes#33384 from ueshin/issues/SPARK-36167/3.2/internal_field.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Introduce `Name` and `Label` type aliases to distinguish what is expected instead of `Any` or `Union[Any, Tuple]`.
- `Label`: `Tuple[Any, ...]`
Internal expression for name-like metadata, like `index_names`, `column_labels`, and `column_label_names` in `InternalFrame`, and similar internal structures.
- `Name`: `Union[Any, Label]`
External expression for user-facing names, which can be scalar values or tuples.
### Why are the changes needed?
Currently `Any` or `Union[Any, Tuple]` is used for name-like types, but type aliases should be used to distinguish what is expected clearly.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Existing tests.
Closes#33159 from ueshin/issues/SPARK-35944/name_and_label.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Cleaning up the type hints in pandas-on-Spark.
- Use a single file `_typing.py` for type variables or aliases
- Rename `IndexOpsLike` to `SeriesOrIndex`.
- Rename `T_Frame` and `T_IndexOps` to `FrameLike` and `IndexOpsLike` respectively
- Introduce `DataFrameOrSeries` for `Union[DataFrame, Series]`
### Why are the changes needed?
This is a cleanup for the mypy check stuff series.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Existing tests.
Closes#33117 from ueshin/issues/SPARK-35859/cleanup.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
### What changes were proposed in this pull request?
Adds more type annotations in the file `python/pyspark/pandas/series.py` and fixes the mypy check failures.
### Why are the changes needed?
We should enable more disallow_untyped_defs mypy checks.
### Does this PR introduce _any_ user-facing change?
Yes.
This PR adds more type annotations in pandas APIs on Spark module, which can impact interaction with development tools for users.
### How was this patch tested?
The mypy check with a new configuration and existing tests should pass.
Closes#33045 from ueshin/issues/SPARK-35476/disallow_untyped_defs_series.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
We propose to
- introduce the Ops class for ExtensionDtypes: `IntegralExtensionOps`, `FractionalExtensionOps`, `StringExtensionOps`
- make the "conversion to pandas" data-type-based for ExtensionDtypes
Non-goal: same arithmetic operation of ExtensionDtypes have different result dtypes between pandas and pandas API on Spark. That should be adjusted in a separated PR if needed.
### Why are the changes needed?
The conversion to pandas includes logic for checking ExtensionDtypes data types and behaving accordingly.
That makes code hard to change or maintain.
Since we have DataTypeOps defined, we are able to dispatch the specific conversion logic to the `ExtensionOps` classes.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Unit tests.
Closes#32910 from xinrong-databricks/datatypeops_pd_ext.
Authored-by: Xinrong Meng <xinrong.meng@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
### What changes were proposed in this pull request?
Modify the `pandas_udf` usage to use type-annotation based pandas_udf or avoid specifying udf types to suppress warnings.
### Why are the changes needed?
The usage of `pandas_udf` in pandas-on-Spark is outdated and shows warnings.
We should use type-annotation based `pandas_udf` or avoid specifying udf types.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Existing tests.
Closes#32913 from ueshin/issues/SPARK-35761/suppress_warnings.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Introduces `InternalField` to manage dtypes and `StructField`s.
`InternalFrame` is already managing dtypes, but when it checks the Spark's data types, column names, and nullabilities, it tries to run the analysis phase each time it needs, which will cause a performance issue.
It will use `InternalField` class which stores the retrieved Spark's data types, column names, and nullabilities, and reuse them. Also, in case those can be known, just update and reuse them without asking Spark.
### Why are the changes needed?
Currently there are some performance issues in the pandas-on-Spark layer.
One of them is accessing Java DataFrame and run analysis phase too many times, especially just for retrieving the current column names or data types.
We should reduce the amount of unnecessary access.
### Does this PR introduce _any_ user-facing change?
Improves the performance in pandas-on-Spark layer:
```py
df = ps.read_parquet("/path/to/test.parquet") # contains ~75 columns
df = df[(df["col"] > 0) & (df["col"] < 10000)]
```
Before the PR, it took about **2.15 sec** and after **1.15 sec**.
### How was this patch tested?
Existing tests.
Closes#32775 from ueshin/issues/SPARK-35638/field.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Make the conversion from/to pandas (for non-ExtensionDtype) data-type-based.
NOTE: Ops class per ExtensionDtype and its data-type-based from/to pandas will be implemented in a separate PR as https://issues.apache.org/jira/browse/SPARK-35614.
### Why are the changes needed?
The conversion from/to pandas includes logic for checking data types and behaving accordingly.
That makes code hard to change or maintain.
Since we have introduced the Ops class per non-ExtensionDtype data type, we ought to make the conversion from/to pandas data-type-based for non-ExtensionDtypes.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Unit tests.
Closes#32592 from xinrong-databricks/datatypeop_pd_conversion.
Authored-by: Xinrong Meng <xinrong.meng@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
### What changes were proposed in this pull request?
This PR proposes applying `black` to pandas API on Spark codes, for improving static analysis.
By executing the `./dev/reformat-python` in the spark home directory, all the code of the pandas API on Spark is fixed according to the static analysis rules.
### Why are the changes needed?
This can be reduces the cost of static analysis during development.
It has been used continuously for about a year in the Koalas project and its convenience has been proven.
### Does this PR introduce _any_ user-facing change?
No, it's dev-only.
### How was this patch tested?
Manually reformat the pandas API on Spark codes by running the `./dev/reformat-python`, and checked the `./dev/lint-python` is passed.
Closes#32779 from itholic/SPARK-35499.
Authored-by: itholic <haejoon.lee@databricks.com>
Signed-off-by: Liang-Chi Hsieh <viirya@gmail.com>
### What changes were proposed in this pull request?
Introduce a util function `spark_column_equals` to check the underlying expressions of columns are the same or not.
### Why are the changes needed?
In pandas on Spark, there are some places checking the underlying expressions of columns are the same or not, but it's done one-by-one.
We should introduce a util function for it.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
The existing tests.
Closes#32680 from ueshin/issues/SPARK-35537/spark_column_equals.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Sets up the `mypy` configuration to enable `disallow_untyped_defs` check for pandas APIs on Spark module.
### Why are the changes needed?
Currently many functions in the main codes in pandas APIs on Spark module are still missing type annotations and disabled `mypy` check `disallow_untyped_defs`.
We should add more type annotations and enable the mypy check.
### Does this PR introduce _any_ user-facing change?
Yes.
This PR adds more type annotations in pandas APIs on Spark module, which can impact interaction with development tools for users.
### How was this patch tested?
The mypy check with a new configuration and existing tests should pass.
Closes#32614 from ueshin/issues/SPARK-35465/disallow_untyped_defs.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
### What changes were proposed in this pull request?
There are still naming related to Koalas in test and function name. This PR addressed them to fit pandas-on-spark.
- kdf -> psdf
- kser -> psser
- kidx -> psidx
- kmidx -> psmidx
- to_koalas() -> to_pandas_on_spark()
### Why are the changes needed?
This is because the name Koalas is no longer used in PySpark.
### Does this PR introduce _any_ user-facing change?
`to_koalas()` function is renamed to `to_pandas_on_spark()`
### How was this patch tested?
Tested in local manually.
After changing the related naming, I checked them one by one.
Closes#32516 from itholic/SPARK-35364.
Authored-by: itholic <haejoon.lee@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
### What changes were proposed in this pull request?
Fixes `mypy` errors and enables `mypy` check for pandas-on-Spark.
### Why are the changes needed?
The `mypy` check for pandas-on-Spark was disabled when the initial porting.
It should be enabled again; otherwise we will miss type checking errors.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
The enabled `mypy` check and existing unit tests should pass.
Closes#32540 from ueshin/issues/SPARK-34941/pandas_mypy.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
### What changes were proposed in this pull request?
This PR proposes to rename Koalas to pandas-on-Spark in main codes
### Why are the changes needed?
To have the correct name in PySpark. NOTE that the official name in the main documentation will be pandas APIs on Spark to be extra clear. pandas-on-Spark is not the official term.
### Does this PR introduce _any_ user-facing change?
No, it's master-only change. It changes the docstring and class names.
### How was this patch tested?
Manually tested via:
```bash
./python/run-tests --python-executable=python3 --modules pyspark-pandas
```
Closes#32166 from HyukjinKwon/rename-koalas.
Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Removes PySpark version dependent codes from `pyspark.pandas` main codes.
### Why are the changes needed?
There are several places to check the PySpark version and switch the logic, but now those are not necessary.
We should remove them.
We will do the same thing after we finish porting tests.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Existing tests.
Closes#32138 from ueshin/issues/SPARK-35039/pyspark_version.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
This PR proposes to fix:
```python
import pyspark.pandas as pp
```
to
```python
import pyspark.pandas as ps
```
### Why are the changes needed?
`pp` might sound offensive in some contexts.
### Does this PR introduce _any_ user-facing change?
The change is in master only. We'll use `ps` as the short name instead of `pp`.
### How was this patch tested?
The CI in this PR will test it out.
Closes#32108 from LSturtew/renaming_pyspark.pandas.
Authored-by: Luka Sturtewagen <luka.sturtewagen@linkit.nl>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Now that we merged the Koalas main code into PySpark code base (#32036), we should enable doctests on the Spark's infrastructure.
### Why are the changes needed?
Currently the pandas-on-Spark modules are not tested at all.
We should enable doctests first, and we will port other unit tests separately later.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
Enabled the whole doctests.
Closes#32069 from ueshin/issues/SPARK-34972/pyspark-pandas_doctests.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
As a first step of [SPARK-34849](https://issues.apache.org/jira/browse/SPARK-34849), this PR proposes porting the Koalas main code into PySpark.
This PR contains minimal changes to the existing Koalas code as follows:
1. `databricks.koalas` -> `pyspark.pandas`
2. `from databricks import koalas as ks` -> `from pyspark import pandas as pp`
3. `ks.xxx -> pp.xxx`
Other than them:
1. Added a line to `python/mypy.ini` in order to ignore the mypy test. See related issue at [SPARK-34941](https://issues.apache.org/jira/browse/SPARK-34941).
2. Added a comment to several lines in several files to ignore the flake8 F401. See related issue at [SPARK-34943](https://issues.apache.org/jira/browse/SPARK-34943).
When this PR is merged, all the features that were previously used in [Koalas](https://github.com/databricks/koalas) will be available in PySpark as well.
Users can access to the pandas API in PySpark as below:
```python
>>> from pyspark import pandas as pp
>>> ppdf = pp.DataFrame({"A": [1, 2, 3], "B": [15, 20, 25]})
>>> ppdf
A B
0 1 15
1 2 20
2 3 25
```
The existing "options and settings" in Koalas are also available in the same way:
```python
>>> from pyspark.pandas.config import set_option, reset_option, get_option
>>> ppser1 = pp.Series([1, 2, 3])
>>> ppser2 = pp.Series([3, 4, 5])
>>> ppser1 + ppser2
Traceback (most recent call last):
...
ValueError: Cannot combine the series or dataframe because it comes from a different dataframe. In order to allow this operation, enable 'compute.ops_on_diff_frames' option.
>>> set_option("compute.ops_on_diff_frames", True)
>>> ppser1 + ppser2
0 4
1 6
2 8
dtype: int64
```
Please also refer to the [API Reference](https://koalas.readthedocs.io/en/latest/reference/index.html) and [Options and Settings](https://koalas.readthedocs.io/en/latest/user_guide/options.html) for more detail.
**NOTE** that this PR intentionally ports the main codes of Koalas first almost as are with minimal changes because:
- Koalas project is fairly large. Making some changes together for PySpark will make it difficult to review the individual change.
Koalas dev includes multiple Spark committers who will review. By doing this, the committers will be able to more easily and effectively review and drive the development.
- Koalas tests and documentation require major changes to make it look great together with PySpark whereas main codes do not require.
- We lately froze the Koalas codebase, and plan to work together on the initial porting. By porting the main codes first as are, it unblocks the Koalas dev to work on other items in parallel.
I promise and will make sure on:
- Rename Koalas to PySpark pandas APIs and/or pandas-on-Spark accordingly in documentation, and the docstrings and comments in the main codes.
- Triage APIs to remove that don’t make sense when Koalas is in PySpark
The documentation changes will be tracked in [SPARK-34885](https://issues.apache.org/jira/browse/SPARK-34885), the test code changes will be tracked in [SPARK-34886](https://issues.apache.org/jira/browse/SPARK-34886).
### Why are the changes needed?
Please refer to:
- [[DISCUSS] Support pandas API layer on PySpark](http://apache-spark-developers-list.1001551.n3.nabble.com/DISCUSS-Support-pandas-API-layer-on-PySpark-td30945.html)
- [[VOTE] SPIP: Support pandas API layer on PySpark](http://apache-spark-developers-list.1001551.n3.nabble.com/VOTE-SPIP-Support-pandas-API-layer-on-PySpark-td30996.html)
### Does this PR introduce _any_ user-facing change?
Yes, now users can use the pandas APIs on Spark
### How was this patch tested?
Manually tested for exposed major APIs and options as described above.
### Koalas contributors
Koalas would not have been possible without the following contributors:
ueshin
HyukjinKwon
rxin
xinrong-databricks
RainFung
charlesdong1991
harupy
floscha
beobest2
thunterdb
garawalid
LucasG0
shril
deepyaman
gioa
fwani
90jam
thoo
AbdealiJK
abishekganesh72
gliptak
DumbMachine
dvgodoy
stbof
nitlev
hjoo
gatorsmile
tomspur
icexelloss
awdavidson
guyao
akhilputhiry
scook12
patryk-oleniuk
tracek
dennyglee
athena15
gstaubli
WeichenXu123
hsubbaraj
lfdversluis
ktksq
shengjh
margaret-databricks
LSturtew
sllynn
manuzhang
jijosg
sadikovi
Closes#32036 from itholic/SPARK-34890.
Authored-by: itholic <haejoon.lee@databricks.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
