changed pos = [] to *pos in date_parser decorator

Implemented using inspector.signature

fincal/core.py

@@ -1,4 +1,5 @@
 import datetime
+import inspect
 from collections import UserDict, UserList
 from dataclasses import dataclass
 from numbers import Number
@@ -16,6 +17,34 @@ class Frequency:
     symbol: str
 
 
+def date_parser(*pos):
+    def parse_dates(func):
+        def wrapper_func(*args, **kwargs):
+            date_format = kwargs.get("date_format", None)
+            args = list(args)
+            sig = inspect.signature(func)
+            params = [i[0] for i in sig.parameters.items()]
+
+            for j in pos:
+                kwarg = params[j]
+                date = kwargs.get(kwarg, None)
+                in_args = False
+                if date is None:
+                    date = args[j]
+                    in_args = True
+
+                parsed_date = _parse_date(date, date_format)
+                if not in_args:
+                    kwargs[kwarg] = parsed_date
+                else:
+                    args[j] = parsed_date
+            return func(*args, **kwargs)
+
+        return wrapper_func
+
+    return parse_dates
+
+
 class AllFrequencies:
     D = Frequency("daily", "days", 1, 1, "D")
     W = Frequency("weekly", "days", 7, 7, "W")
@@ -157,7 +186,7 @@ class TimeSeriesCore(UserDict):
     def __init__(
         self, data: List[Iterable], frequency: Literal["D", "W", "M", "Q", "H", "Y"], date_format: str = "%Y-%m-%d"
     ):
-        """Instantiate a TimeSeries object
+        """Instantiate a TimeSeriesCore object
 
         Parameters
         ----------
@@ -221,7 +250,7 @@ class TimeSeriesCore(UserDict):
     def _get_printable_slice(self, n: int):
         """Helper function for __repr__ and __str__
 
-            Returns a slice of the dataframe from beginning and end.
+        Returns a slice of the dataframe from beginning and end.
         """
 
         printable = {}

fincal/fincal.py

@@ -5,7 +5,7 @@ from typing import Iterable, List, Literal, Mapping, Union
 
 from dateutil.relativedelta import relativedelta
 
-from .core import AllFrequencies, TimeSeriesCore
+from .core import AllFrequencies, TimeSeriesCore, date_parser
 from .utils import (
     _find_closest_date,
     _interval_to_years,
@@ -184,6 +184,7 @@ class TimeSeries(TimeSeriesCore):
 
         return self.__class__(new_ts, frequency=self.frequency.symbol)
 
+    @date_parser(1)
     def calculate_returns(
         self,
         as_on: Union[str, datetime.datetime],
@@ -260,7 +261,7 @@ class TimeSeries(TimeSeriesCore):
         (datetime.datetime(2020, 1, 1, 0, 0), .0567)
         """
 
-        as_on = _parse_date(as_on, date_format)
+        # as_on = _parse_date(as_on, date_format)
         as_on_delta, prior_delta = _preprocess_match_options(as_on_match, prior_match, closest)
 
         prev_date = as_on - relativedelta(**{interval_type: interval_value})
@@ -276,6 +277,7 @@ class TimeSeries(TimeSeriesCore):
             returns = returns ** (1 / years)
         return (current[0] if return_actual_date else as_on), returns - 1
 
+    @date_parser(1, 2)
     def calculate_rolling_returns(
         self,
         from_date: Union[datetime.date, str],
@@ -356,8 +358,8 @@ class TimeSeries(TimeSeriesCore):
             TimeSeries.calculate_returns
         """
 
-        from_date = _parse_date(from_date, date_format)
-        to_date = _parse_date(to_date, date_format)
+        # from_date = _parse_date(from_date, date_format)
+        # to_date = _parse_date(to_date, date_format)
 
         if frequency is None:
             frequency = self.frequency

fincal/utils.py

@@ -13,7 +13,7 @@ class FincalOptions:
 
 def _parse_date(date: str, date_format: str = None):
     """Parses date and handles errors"""
-
+    # print(date, date_format)
     if isinstance(date, (datetime.datetime, datetime.date)):
         return datetime.datetime.fromordinal(date.toordinal())