support of seasonalities as list of string

Summary:
Currently, prophet defines a custom enum for seasonalities. There is no proper way to expose this enum to configerator to validate seasonality param at authoring time.

We can add a new thrift structure, but it will add maintenance overhead as we need to keep mapping between thrift structure and the enum.

As any python enum class expose the enum as a key, we can use this to have an implicit mapping between gp param and kats enum.

This diff enable user to use the seasonality name and the code will convert it to enum during initialization

Differential Revision: D51238962

fbshipit-source-id: 5f35f8d8ffcfe3db6b498d1bcdb460004e76c579

kats/detectors/prophet_detector.py

@@ -138,18 +138,37 @@ class SeasonalityTypes(Enum):
 EMPTY_LIST: List[SeasonalityTypes] = []
 
 
+def to_seasonality(seasonality: Union[str, SeasonalityTypes]) -> SeasonalityTypes:
+    if isinstance(seasonality, str):
+        try:
+            return SeasonalityTypes[seasonality.upper()]
+        except KeyError:
+            raise ValueError(
+                f"Invalid seasonality type: {seasonality}. Valid types are: {list(SeasonalityTypes)}"
+            )
+    elif isinstance(seasonality, SeasonalityTypes):
+        return seasonality
+    else:
+        raise ValueError(
+            f"Expected string or SeasonalityTypes, got {type(seasonality)} instead"
+        )
+
+
 def seasonalities_to_dict(
     seasonalities: Union[
         SeasonalityTypes,
         List[SeasonalityTypes],
+        List[str],
         Dict[SeasonalityTypes, Union[bool, str]],
     ]
 ) -> Dict[SeasonalityTypes, Union[bool, str]]:
 
     if isinstance(seasonalities, SeasonalityTypes):
         seasonalities = {seasonalities: True}
     elif isinstance(seasonalities, list):
-        seasonalities = {seasonality: True for seasonality in seasonalities}
+        seasonalities = {
+            to_seasonality(seasonality): True for seasonality in seasonalities
+        }
     elif seasonalities is None:
         seasonalities = {}
     return seasonalities
@@ -253,6 +272,7 @@ def __init__(
             Union[
                 SeasonalityTypes,
                 List[SeasonalityTypes],
+                List[str],
                 Dict[SeasonalityTypes, Union[bool, str]],
             ]
         ] = EMPTY_LIST,

kats/tests/detectors/test_prophet_detector.py

@@ -5,6 +5,7 @@
 
 import random
 from datetime import timedelta
+from typing import Union
 from unittest import TestCase
 
 import numpy as np
@@ -17,6 +18,7 @@
     ProphetScoreFunction,
     ProphetTrendDetectorModel,
     SeasonalityTypes,
+    to_seasonality,
 )
 from kats.utils.simulator import Simulator
 from parameterized.parameterized import parameterized
@@ -872,3 +874,21 @@ def test_pmm_use_case(self) -> None:
         self.assertEqual(
             response_wo_historical_data.scores.value.shape, hist_ts.value.shape
         )
+
+    # pyre-fixme[56]: Pyre was not able to infer the type of the decorator `parameter...
+    @parameterized.expand(
+        [
+            ("day", SeasonalityTypes.DAY),
+            ("week", SeasonalityTypes.WEEK),
+            ("weekend", SeasonalityTypes.WEEKEND),
+            ("year", SeasonalityTypes.YEAR),
+            (SeasonalityTypes.DAY, SeasonalityTypes.DAY),
+            (SeasonalityTypes.WEEK, SeasonalityTypes.WEEK),
+            (SeasonalityTypes.WEEKEND, SeasonalityTypes.WEEKEND),
+            (SeasonalityTypes.YEAR, SeasonalityTypes.YEAR),
+        ]
+    )
+    def test_to_seasonality(
+        self, actual: Union[str, SeasonalityTypes], expected: SeasonalityTypes
+    ) -> None:
+        self.assertEqual(to_seasonality(actual), expected)