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miner/frontend/normstrategy.py

139 lines
3.9 KiB

from abc import ABC, abstractmethod
from pandas import DataFrame, Series
from pandas.api.types import is_numeric_dtype
from typing import Any, Union
class DataFrameFunction(ABC):
"""A command that may be applied in-place to a dataframe."""
@abstractmethod
def apply(self, df: DataFrame, label: str, series: Series) -> DataFrame:
"""Apply the current function to the given dataframe, in-place.
The series is described by its label and dataframe."""
return df
class MVStrategy(DataFrameFunction):
"""A way to handle missing values in a dataframe."""
@staticmethod
def list_available(df: DataFrame, series: Series) -> list['MVStrategy']:
"""Get all the strategies that can be used."""
choices = [DropStrategy(), ModeStrategy()]
if is_numeric_dtype(series):
choices.extend((MeanStrategy(), MedianStrategy(), LinearRegressionStrategy()))
return choices
class ScalingStrategy(DataFrameFunction):
"""A way to handle missing values in a dataframe."""
@staticmethod
def list_available(df: DataFrame, series: Series) -> list['MVStrategy']:
"""Get all the strategies that can be used."""
choices = [KeepStrategy()]
if is_numeric_dtype(series):
choices.extend((MinMaxStrategy(), ZScoreStrategy()))
if series.sum() != 0:
choices.append(UnitLengthStrategy())
return choices
class DropStrategy(MVStrategy):
#@typing.override
def apply(self, df: DataFrame, label: str, series: Series) -> DataFrame:
df.dropna(subset=label, inplace=True)
return df
def __str__(self) -> str:
return "Drop"
class PositionStrategy(MVStrategy):
#@typing.override
def apply(self, df: DataFrame, label: str, series: Series) -> DataFrame:
series.fillna(self.get_value(series), inplace=True)
return df
@abstractmethod
def get_value(self, series: Series) -> Any:
pass
class MeanStrategy(PositionStrategy):
#@typing.override
def get_value(self, series: Series) -> Union[int, float]:
return series.mean()
def __str__(self) -> str:
return "Use mean"
class MedianStrategy(PositionStrategy):
#@typing.override
def get_value(self, series: Series) -> Union[int, float]:
return series.median()
def __str__(self) -> str:
return "Use median"
class ModeStrategy(PositionStrategy):
#@typing.override
def get_value(self, series: Series) -> Any:
return series.mode()[0]
def __str__(self) -> str:
return "Use mode"
class LinearRegressionStrategy(MVStrategy):
def apply(self, df: DataFrame, label: str, series: Series) -> DataFrame:
series.interpolate(inplace=True)
return df
def __str__(self) -> str:
return "Use linear regression"
class KeepStrategy(ScalingStrategy):
#@typing.override
def apply(self, df: DataFrame, label: str, series: Series) -> DataFrame:
return df
def __str__(self) -> str:
return "No-op"
class MinMaxStrategy(ScalingStrategy):
#@typing.override
def apply(self, df: DataFrame, label: str, series: Series) -> DataFrame:
minimum = series.min()
maximum = series.max()
df[label] = (series - minimum) / (maximum - minimum)
return df
def __str__(self) -> str:
return "Min-max"
class ZScoreStrategy(ScalingStrategy):
#@typing.override
def apply(self, df: DataFrame, label: str, series: Series) -> DataFrame:
df[label] = (series - series.mean()) / series.std()
return df
def __str__(self) -> str:
return "Z-Score"
class UnitLengthStrategy(ScalingStrategy):
#@typing.override
def apply(self, df: DataFrame, label: str, series: Series) -> DataFrame:
df[label] = series / series.sum()
return df
def __str__(self) -> str:
return "Unit length"