Current File : //backups/router/usr/local/lib/python3.11/site-packages/duckdb/experimental/spark/sql/group.py
#
# 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.
#
from ..exception import ContributionsAcceptedError
from typing import Callable, TYPE_CHECKING, overload, Dict, Union, List
from .column import Column
from .session import SparkSession
from .dataframe import DataFrame
from .functions import _to_column_expr
from ._typing import ColumnOrName
from .types import NumericType
if TYPE_CHECKING:
from ._typing import LiteralType
__all__ = ["GroupedData", "Grouping"]
def _api_internal(self: "GroupedData", name: str, *cols: str) -> DataFrame:
expressions = ",".join(list(cols))
group_by = str(self._grouping) if self._grouping else ""
projections = self._grouping.get_columns()
jdf = getattr(self._df.relation, "apply")(
function_name=name, # aggregate function
function_aggr=expressions, # inputs to aggregate
group_expr=group_by, # groups
projected_columns=projections, # projections
)
return DataFrame(jdf, self.session)
def df_varargs_api(f: Callable[..., DataFrame]) -> Callable[..., DataFrame]:
def _api(self: "GroupedData", *cols: str) -> DataFrame:
name = f.__name__
return _api_internal(self, name, *cols)
_api.__name__ = f.__name__
_api.__doc__ = f.__doc__
return _api
class Grouping:
def __init__(self, *cols: "ColumnOrName", **kwargs):
self._type = ""
self._cols = [_to_column_expr(x) for x in cols]
if 'special' in kwargs:
special = kwargs['special']
accepted_special = ["cube", "rollup"]
assert special in accepted_special
self._type = special
def get_columns(self) -> str:
columns = ",".join([str(x) for x in self._cols])
return columns
def __str__(self):
columns = self.get_columns()
if self._type:
return self._type + '(' + columns + ')'
return columns
class GroupedData:
"""
A set of methods for aggregations on a :class:`DataFrame`,
created by :func:`DataFrame.groupBy`.
"""
def __init__(self, grouping: Grouping, df: DataFrame):
self._grouping = grouping
self._df = df
self.session: SparkSession = df.session
def __repr__(self) -> str:
return str(self._df)
def count(self) -> DataFrame:
"""Counts the number of records for each group.
Examples
--------
>>> df = spark.createDataFrame(
... [(2, "Alice"), (3, "Alice"), (5, "Bob"), (10, "Bob")], ["age", "name"])
>>> df.show()
+---+-----+
|age| name|
+---+-----+
| 2|Alice|
| 3|Alice|
| 5| Bob|
| 10| Bob|
+---+-----+
Group-by name, and count each group.
>>> df.groupBy(df.name).count().sort("name").show()
+-----+-----+
| name|count|
+-----+-----+
|Alice| 2|
| Bob| 2|
+-----+-----+
"""
return _api_internal(self, "count").withColumnRenamed('count_star()', 'count')
@df_varargs_api
def mean(self, *cols: str) -> DataFrame:
"""Computes average values for each numeric columns for each group.
:func:`mean` is an alias for :func:`avg`.
Parameters
----------
cols : str
column names. Non-numeric columns are ignored.
"""
def avg(self, *cols: str) -> DataFrame:
"""Computes average values for each numeric columns for each group.
:func:`mean` is an alias for :func:`avg`.
Parameters
----------
cols : str
column names. Non-numeric columns are ignored.
Examples
--------
>>> df = spark.createDataFrame([
... (2, "Alice", 80), (3, "Alice", 100),
... (5, "Bob", 120), (10, "Bob", 140)], ["age", "name", "height"])
>>> df.show()
+---+-----+------+
|age| name|height|
+---+-----+------+
| 2|Alice| 80|
| 3|Alice| 100|
| 5| Bob| 120|
| 10| Bob| 140|
+---+-----+------+
Group-by name, and calculate the mean of the age in each group.
>>> df.groupBy("name").avg('age').sort("name").show()
+-----+--------+
| name|avg(age)|
+-----+--------+
|Alice| 2.5|
| Bob| 7.5|
+-----+--------+
Calculate the mean of the age and height in all data.
>>> df.groupBy().avg('age', 'height').show()
+--------+-----------+
|avg(age)|avg(height)|
+--------+-----------+
| 5.0| 110.0|
+--------+-----------+
"""
columns = list(cols)
if len(columns) == 0:
schema = self._df.schema
# Take only the numeric types of the relation
columns: List[str] = [x.name for x in schema.fields if isinstance(x.dataType, NumericType)]
return _api_internal(self, "avg", *columns)
@df_varargs_api
def max(self, *cols: str) -> DataFrame:
"""Computes the max value for each numeric columns for each group.
Examples
--------
>>> df = spark.createDataFrame([
... (2, "Alice", 80), (3, "Alice", 100),
... (5, "Bob", 120), (10, "Bob", 140)], ["age", "name", "height"])
>>> df.show()
+---+-----+------+
|age| name|height|
+---+-----+------+
| 2|Alice| 80|
| 3|Alice| 100|
| 5| Bob| 120|
| 10| Bob| 140|
+---+-----+------+
Group-by name, and calculate the max of the age in each group.
>>> df.groupBy("name").max("age").sort("name").show()
+-----+--------+
| name|max(age)|
+-----+--------+
|Alice| 3|
| Bob| 10|
+-----+--------+
Calculate the max of the age and height in all data.
>>> df.groupBy().max("age", "height").show()
+--------+-----------+
|max(age)|max(height)|
+--------+-----------+
| 10| 140|
+--------+-----------+
"""
@df_varargs_api
def min(self, *cols: str) -> DataFrame:
"""Computes the min value for each numeric column for each group.
Parameters
----------
cols : str
column names. Non-numeric columns are ignored.
Examples
--------
>>> df = spark.createDataFrame([
... (2, "Alice", 80), (3, "Alice", 100),
... (5, "Bob", 120), (10, "Bob", 140)], ["age", "name", "height"])
>>> df.show()
+---+-----+------+
|age| name|height|
+---+-----+------+
| 2|Alice| 80|
| 3|Alice| 100|
| 5| Bob| 120|
| 10| Bob| 140|
+---+-----+------+
Group-by name, and calculate the min of the age in each group.
>>> df.groupBy("name").min("age").sort("name").show()
+-----+--------+
| name|min(age)|
+-----+--------+
|Alice| 2|
| Bob| 5|
+-----+--------+
Calculate the min of the age and height in all data.
>>> df.groupBy().min("age", "height").show()
+--------+-----------+
|min(age)|min(height)|
+--------+-----------+
| 2| 80|
+--------+-----------+
"""
@df_varargs_api
def sum(self, *cols: str) -> DataFrame:
"""Computes the sum for each numeric columns for each group.
Parameters
----------
cols : str
column names. Non-numeric columns are ignored.
Examples
--------
>>> df = spark.createDataFrame([
... (2, "Alice", 80), (3, "Alice", 100),
... (5, "Bob", 120), (10, "Bob", 140)], ["age", "name", "height"])
>>> df.show()
+---+-----+------+
|age| name|height|
+---+-----+------+
| 2|Alice| 80|
| 3|Alice| 100|
| 5| Bob| 120|
| 10| Bob| 140|
+---+-----+------+
Group-by name, and calculate the sum of the age in each group.
>>> df.groupBy("name").sum("age").sort("name").show()
+-----+--------+
| name|sum(age)|
+-----+--------+
|Alice| 5|
| Bob| 15|
+-----+--------+
Calculate the sum of the age and height in all data.
>>> df.groupBy().sum("age", "height").show()
+--------+-----------+
|sum(age)|sum(height)|
+--------+-----------+
| 20| 440|
+--------+-----------+
"""
@overload
def agg(self, *exprs: Column) -> DataFrame:
...
@overload
def agg(self, __exprs: Dict[str, str]) -> DataFrame:
...
def agg(self, *exprs: Union[Column, Dict[str, str]]) -> DataFrame:
"""Compute aggregates and returns the result as a :class:`DataFrame`.
The available aggregate functions can be:
1. built-in aggregation functions, such as `avg`, `max`, `min`, `sum`, `count`
2. group aggregate pandas UDFs, created with :func:`pyspark.sql.functions.pandas_udf`
.. note:: There is no partial aggregation with group aggregate UDFs, i.e.,
a full shuffle is required. Also, all the data of a group will be loaded into
memory, so the user should be aware of the potential OOM risk if data is skewed
and certain groups are too large to fit in memory.
.. seealso:: :func:`pyspark.sql.functions.pandas_udf`
If ``exprs`` is a single :class:`dict` mapping from string to string, then the key
is the column to perform aggregation on, and the value is the aggregate function.
Alternatively, ``exprs`` can also be a list of aggregate :class:`Column` expressions.
.. versionadded:: 1.3.0
.. versionchanged:: 3.4.0
Supports Spark Connect.
Parameters
----------
exprs : dict
a dict mapping from column name (string) to aggregate functions (string),
or a list of :class:`Column`.
Notes
-----
Built-in aggregation functions and group aggregate pandas UDFs cannot be mixed
in a single call to this function.
Examples
--------
>>> from pyspark.sql import functions as F
>>> from pyspark.sql.functions import pandas_udf, PandasUDFType
>>> df = spark.createDataFrame(
... [(2, "Alice"), (3, "Alice"), (5, "Bob"), (10, "Bob")], ["age", "name"])
>>> df.show()
+---+-----+
|age| name|
+---+-----+
| 2|Alice|
| 3|Alice|
| 5| Bob|
| 10| Bob|
+---+-----+
Group-by name, and count each group.
>>> df.groupBy(df.name)
GroupedData[grouping...: [name...], value: [age: bigint, name: string], type: GroupBy]
>>> df.groupBy(df.name).agg({"*": "count"}).sort("name").show()
+-----+--------+
| name|count(1)|
+-----+--------+
|Alice| 2|
| Bob| 2|
+-----+--------+
Group-by name, and calculate the minimum age.
>>> df.groupBy(df.name).agg(F.min(df.age)).sort("name").show()
+-----+--------+
| name|min(age)|
+-----+--------+
|Alice| 2|
| Bob| 5|
+-----+--------+
Same as above but uses pandas UDF.
>>> @pandas_udf('int', PandasUDFType.GROUPED_AGG) # doctest: +SKIP
... def min_udf(v):
... return v.min()
...
>>> df.groupBy(df.name).agg(min_udf(df.age)).sort("name").show() # doctest: +SKIP
+-----+------------+
| name|min_udf(age)|
+-----+------------+
|Alice| 2|
| Bob| 5|
+-----+------------+
"""
assert exprs, "exprs should not be empty"
if len(exprs) == 1 and isinstance(exprs[0], dict):
raise ContributionsAcceptedError
else:
# Columns
assert all(isinstance(c, Column) for c in exprs), "all exprs should be Column"
expressions = list(self._grouping._cols)
expressions.extend([x.expr for x in exprs])
group_by = str(self._grouping)
rel = self._df.relation.select(*expressions, groups=group_by)
return DataFrame(rel, self.session)
# TODO: add 'pivot'
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