from __future__ import annotations
import operator
import warnings
from dataclasses import dataclass, fields
from statistics import mean
from typing import Generic, List, Optional, TypeVar
import pandas as pd
# Metrics take on float or integer values
# Some metrics may return `None` values when the score fails to be computed
NumericType = TypeVar('NumericType', float, int, Optional[float], Optional[int])
[docs]@dataclass
class MetricValue(Generic[NumericType]):
'''A rich object that is the output of any langcheck.metrics function.'''
metric_name: str
metric_values: List[NumericType]
prompts: Optional[List[str]]
generated_outputs: Optional[List[str]]
reference_outputs: Optional[List[str]]
sources: Optional[List[str]]
explanations: Optional[List[Optional[
str]]] # An explanation can be None if the metric could not be computed
language: Optional[str]
[docs] def to_df(self) -> pd.DataFrame:
'''Returns a DataFrame of metric values for each data point.'''
dataframe_cols = {
'prompt': self.prompts,
'source': self.sources,
'generated_output': self.generated_outputs,
'reference_output': self.reference_outputs,
'explanation': self.explanations,
'metric_value': self.metric_values,
}
return pd.DataFrame(dataframe_cols)
def __str__(self) -> str:
'''Returns a string representation of an
:class:`~langcheck.metrics.metric_value.MetricValue` object.
'''
return (f'Metric: {self.metric_name}\n'
f'{self.to_df()}')
def __repr__(self) -> str:
'''Returns a string representation of an
:class:`~langcheck.metrics.metric_value.MetricValue` object.
'''
return str(self)
def _repr_html_(self) -> str:
'''Returns an HTML representation of an
:class:`~langcheck.metrics.metric_value.MetricValue`, which is
automatically called by Jupyter notebooks.
'''
return (f'Metric: {self.metric_name}<br>'
f'{self.to_df()._repr_html_()}' # type: ignore
)
def __lt__(self, threshold: float | int) -> MetricValueWithThreshold:
'''Allows the user to write a `metric_value < 0.5` expression.'''
all_fields = {f.name: getattr(self, f.name) for f in fields(self)}
return MetricValueWithThreshold(**all_fields,
threshold=threshold,
threshold_op='<')
def __le__(self, threshold: float | int) -> MetricValueWithThreshold:
'''Allows the user to write a `metric_value <= 0.5` expression.'''
all_fields = {f.name: getattr(self, f.name) for f in fields(self)}
return MetricValueWithThreshold(**all_fields,
threshold=threshold,
threshold_op='<=')
def __gt__(self, threshold: float | int) -> MetricValueWithThreshold:
'''Allows the user to write a `metric_value > 0.5` expression.'''
all_fields = {f.name: getattr(self, f.name) for f in fields(self)}
return MetricValueWithThreshold(**all_fields,
threshold=threshold,
threshold_op='>')
def __ge__(self, threshold: float | int) -> MetricValueWithThreshold:
'''Allows the user to write a `metric_value >= 0.5` expression.'''
all_fields = {f.name: getattr(self, f.name) for f in fields(self)}
return MetricValueWithThreshold(**all_fields,
threshold=threshold,
threshold_op='>=')
def __eq__(self, threshold: float | int) -> MetricValueWithThreshold:
'''Allows the user to write a `metric_value == 0.5` expression.'''
all_fields = {f.name: getattr(self, f.name) for f in fields(self)}
return MetricValueWithThreshold(**all_fields,
threshold=threshold,
threshold_op='==')
def __ne__(self, threshold: float | int) -> MetricValueWithThreshold:
'''Allows the user to write a `metric_value != 0.5` expression.'''
all_fields = {f.name: getattr(self, f.name) for f in fields(self)}
return MetricValueWithThreshold(**all_fields,
threshold=threshold,
threshold_op='!=')
[docs] def all(self) -> bool:
'''Equivalent to all(metric_value.metric_values). This is mostly useful
for binary metric functions.
'''
return all(self.metric_values)
[docs] def any(self) -> bool:
'''Equivalent to any(metric_value.metric_values). This is mostly useful
for binary metric functions.
'''
return any(self.metric_values)
def __bool__(self):
raise ValueError(
'A MetricValue cannot be used as a boolean. '
'Try an expression like `metric_value > 0.5`, '
'`metric_value.all()`, or `metric_value.any()` instead.')
[docs] def scatter(self, jupyter_mode: str = 'inline') -> None:
'''Shows an interactive scatter plot of all data points in MetricValue.
Intended to be used in a Jupyter notebook.
This is a convenience function that calls
:func:`langcheck.plot.scatter()`.
'''
from langcheck.plot import scatter as plot_scatter
# Type ignore because a Self type is only valid in class contexts
return plot_scatter(
self, # type: ignore[reportGeneralTypeIssues]
jupyter_mode=jupyter_mode)
[docs] def histogram(self, jupyter_mode: str = 'inline') -> None:
'''Shows an interactive histogram of all data points in MetricValue.
Intended to be used in a Jupyter notebook.
This is a convenience function that calls
:func:`langcheck.plot.histogram()`.
'''
from langcheck.plot import histogram as plot_histogram
# Type ignore because a Self type is only valid in class contexts
return plot_histogram(
self, # type: ignore[reportGeneralTypeIssues]
jupyter_mode=jupyter_mode)
[docs]@dataclass
class MetricValueWithThreshold(MetricValue):
'''A rich object that is the output of comparing an
:class:`~langcheck.metrics.metric_value.MetricValue` object,
e.g. `metric_value >= 0.5`.
'''
threshold: float | int
threshold_op: str # One of '<', '<=', '>', '>=', '==', '!='
def __post_init__(self) -> None:
'''Computes self.pass_rate and self.threshold_results based on the
constructor arguments.
'''
operators = {
'<': operator.lt,
'<=': operator.le,
'>': operator.gt,
'>=': operator.ge,
'==': operator.eq,
'!=': operator.ne
}
if self.threshold_op not in operators:
raise ValueError(f'Invalid threshold operator: {self.threshold_op}')
if self.threshold is None:
raise ValueError("A threshold of `None` is not supported.")
if None in self.metric_values:
warnings.warn(
"The threshold result for `None` values in `metric_values` will"
" always be `False`.")
# Set the result to `False` if the metric value is `None`
self._threshold_results = [
operators[self.threshold_op](x, self.threshold)
if x is not None else False for x in self.metric_values
]
self._pass_rate = mean(self._threshold_results)
@property
def pass_rate(self) -> float:
'''Returns the proportion of data points that pass the threshold.'''
return self._pass_rate
@property
def threshold_results(self) -> List[bool]:
'''Returns a list of booleans indicating whether each data point passes
the threshold.
'''
return self._threshold_results
[docs] def to_df(self) -> pd.DataFrame:
'''Returns a DataFrame of metric values for each data point.'''
dataframe = super().to_df()
dataframe['threshold_test'] = [
f'{self.threshold_op} {self.threshold}' for _ in self.metric_values
]
dataframe['threshold_result'] = self.threshold_results
return dataframe
def __str__(self) -> str:
'''Returns a string representation of an
:class:`~langcheck.metrics.metric_value.MetricValue`.
'''
return (f'Metric: {self.metric_name}\n'
f'Pass Rate: {round(self.pass_rate*100, 2)}%\n'
f'{self.to_df()}')
def __repr__(self) -> str:
'''Returns a string representation of an
:class:`~langcheck.metrics.metric_value.MetricValue` object.
'''
return str(self)
def _repr_html_(self) -> str:
'''Returns an HTML representation of an
:class:`~langcheck.metrics.metric_value.MetricValue`, which is
automatically called by Jupyter notebooks.
'''
return (f'Metric: {self.metric_name}<br>'
f'Pass Rate: {round(self.pass_rate*100, 2)}%<br>'
f'{self.to_df()._repr_html_()}' # type: ignore
)
[docs] def all(self) -> bool:
'''Returns True if all data points pass the threshold.'''
return all(self.threshold_results)
[docs] def any(self) -> bool:
'''Returns True if any data points pass the threshold.'''
return any(self.threshold_results)
def __bool__(self) -> bool:
'''Allows the user to write an `assert metric_value > 0.5` or
`if metric_value > 0.5:` expression. This is shorthand for
`assert (metric_value > 0.5).all()`.
'''
return self.all()
