From 130f4e58e91ce326b3badda347e2fe1f2a76feef Mon Sep 17 00:00:00 2001
From: Gourav Kumar <gourav2711@gmail.com>
Date: Wed, 18 May 2022 21:39:57 -0700
Subject: [PATCH] started working on transform with aggregation

---
 fincal/fincal.py |  39 +++++++++++++++++++++++++++++++++++++++
 requirements.txt | Bin 1002 -> 942 bytes
 2 files changed, 39 insertions(+)

diff --git a/fincal/fincal.py b/fincal/fincal.py
index c0b2c94..3cc7bfb 100644
--- a/fincal/fincal.py
+++ b/fincal/fincal.py
@@ -783,6 +783,45 @@ class TimeSeries(TimeSeriesCore):
 
         return statistics.mean(self.values)
 
+    def transform(
+        self, to_frequency: Literal["W", "M", "Q", "H", "Y"], method: Literal["sum", "mean"], eomonth: bool
+    ) -> TimeSeries:
+        """Transform a time series object into a lower frequency object with an aggregation function.
+
+        Parameters
+        ----------
+        to_frequency:
+            Frequency to which the time series needs to be transformed
+
+        method:
+            Aggregation method to be used. Can be either mean or sum
+
+        eomonth:
+            User end of month dates. Only applicable for frequencies monthly and lower.
+
+        Returns
+        -------
+            Returns a TimeSeries object
+
+        Raises
+        -------
+            ValueError:
+                * If invalid input is passed for frequency
+                * if invalid input is passed for method
+                * If to_frequency is higher than the current frequency
+        """
+
+        try:
+            to_frequency: Frequency = getattr(AllFrequencies, to_frequency)
+        except AttributeError:
+            raise ValueError(f"Invalid argument for to_frequency {to_frequency}")
+
+        if to_frequency.days <= self.frequency.days:
+            raise ValueError("TimeSeries can be only shrunk to a lower frequency")
+
+        if method not in ["sum", "mean"]:
+            raise ValueError(f"Method not recognised: {method}")
+
 
 def _preprocess_csv(file_path: str | pathlib.Path, delimiter: str = ",", encoding: str = "utf-8") -> List[list]:
     """Preprocess csv data"""
diff --git a/requirements.txt b/requirements.txt
index af4b474ae3c722c8ac5094cab6e7c45f32a3d33f..0f071b335a47c3e0b4a7e76d4d64df0f8df7edf2 100644
GIT binary patch
delta 16
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delta 64
zcmZ3-{)&CWG)BohhEj%Hh609423sIBWYA+U0zx1;c_O2>XdXifLn1>lT+Re2W4L)U
H<8MX))$R?q