Holidays

.gitignore

@@ -5,3 +5,4 @@ Cargo.lock
 target/
 .hypothesis
 *.pyc
+.vscode

README.md

@@ -22,24 +22,37 @@ $ pip install polars-business
 To use it, you'll need to `import polars_business`, and then you'll be a `.business` accessor
 on your expressions!
 
-Currently there's only a single function: `advance_n_days`.
+Currently there's only a single function: `advance_n_days`. It takes arguments:
+- `n`: number of days to advance. This can be an expression.
+- `holidays`: list of holidays in `datetime.date` format. The Python `holidays` package may
+  be useful here. You can install it with `pip install holidays`, and then you can get a list
+  of holidays for a given country with (for example, `'UK'`):
+  ```
+  import holidays 
+
+  list(holidays.country_holidays('UK', years=[2020, 2021, 2022, 2023]))
+  ```
 
 Example
 -------
 
-Here's an example of how to shift a date range forwards by 5 business days (i.e. Monday to Friday, excluding weekends):
+Given some dates, can you shift them all forwards by 5 business days (according to the UK holiday calendar)?
+
+With `polars-business`, this is easy:
 ```python
+from datetime import date
+
+import holidays
 import polars as pl
 import polars_business
 
-from datetime import date
 
+uk_holidays = holidays.country_holidays('UK', years=[2023, 2024])
 df = pl.DataFrame({
-    "dates": pl.date_range(date(2000, 1, 1), date(9999, 1, 1), eager=True),
+    "dates": [date(2023, 4, 2), date(2023, 9, 1), date(2024, 1, 4)]
 })
-df = df.filter(pl.col('dates').dt.weekday() <6)
 
-print(df.with_columns(dates_shifted=pl.col('dates').business.advance_n_days(n=5)))
+print(df.with_columns(dates_shifted=pl.col('dates').business.advance_n_days(n=5, holidays=uk_holidays)))
 ```
 
 Note
@@ -50,13 +63,27 @@ What to expected
 ----------------
 The following will hopefully come relatively soon:
 - support for `Datetime`s
-- support for custom holiday calendars
 - support for rolling forwards/backwards to the next
   valid business date (if not already on one)
 
 Ideas for future development:
 - business date range
-- support for custom mask
+- support for custom week mask
+
+Benchmarks
+----------
+
+The following timings can be verified using the `perf.py` script.
+
+### Adding 17 business days to 10 million dates (no holidays)
+
+- Polars-business 0.058
+- NumPy 0.092
+- pandas 0.801
 
+### Adding 17 business days to 10 million dates (UK holidays for 2020-2023)
 
-Currently there's only a single function: `advance_n_days`.
+- Polars-business 0.406
+- NumPy 0.417
+- pandas: omitted as pandas doesn't (yet) vectorise `CustomBusinessDay`, so
+  we'd likely be talking about minutes

src/Makefile

@@ -2,24 +2,39 @@
 SHELL=/bin/bash
 
 venv:  ## Set up virtual environment
-	python3 -m venv venv
-	venv/bin/pip install -r requirements.txt
+	. ../.venv/bin/activate
 
 install: venv
 	unset CONDA_PREFIX && \
-	source venv/bin/activate && maturin develop -m polars_business/Cargo.toml
+	source ../.venv/bin/activate && maturin develop -m polars_business/Cargo.toml
 
 install-release: venv
 	unset CONDA_PREFIX && \
-	source venv/bin/activate && maturin develop --release -m polars_business/Cargo.toml
+	source ../.venv/bin/activate && maturin develop --release -m polars_business/Cargo.toml
+
+build: venv
+	unset CONDA_PREFIX && \
+	source ../.venv/bin/activate && maturin develop --release -m polars_business/Cargo.toml
 
 clean:
-	-@rm -r venv
+	-@rm -r ../.venv
 	-@cd polars_business && cargo clean
 
 
 run: install
-	source venv/bin/activate && python run.py
+	source ../.venv/bin/activate && python run.py
 
 run-release: install-release
-	source venv/bin/activate && python run.py
+	source ../.venv/bin/activate && python run.py
+
+test: build
+	pytest ../tests
+
+clippy: venv
+	cargo clippy -p polars_business
+
+fmt: venv
+	cargo fmt --all
+	black .
+
+pre-commit: clippy fmt 

src/perf.py

@@ -0,0 +1,75 @@
+
+import timeit
+import numpy as np
+
+# BENCHMARK 1: NO HOLIDAYS INVOLVED
+
+setup = """
+import polars as pl
+import polars_business
+from datetime import date
+import numpy as np
+import pandas as pd
+import holidays
+import warnings
+
+dates = pl.date_range(date(2020, 1, 1), date(2024, 1, 1), closed='left', eager=True)
+dates = dates.filter(dates.dt.weekday() < 6)
+size = 10_000_000
+input_dates = np.random.choice(dates, size)
+
+df = pl.DataFrame({
+    'ts': input_dates,
+})
+
+df_pd = pd.DataFrame({
+    'ts': input_dates,
+})
+"""
+
+def time_it(statement):
+    results = np.array(timeit.Timer(
+        stmt=statement,
+        setup=setup,
+        )
+        .repeat(7, 3)
+    )/3
+    return round(min(results), 3)
+
+print('Polars-business: ', time_it("result_pl = df.select(pl.col('ts').business.advance_n_days(n=17))"))
+
+print('NumPy: ', time_it("result_np = np.busday_offset(input_dates, 17)"))
+
+print('pandas: ', time_it("result_pd = df_pd['ts'] + pd.tseries.offsets.BusinessDay(17)"))
+
+# BENCHMARK 2: WITH HOLIDAYS
+
+setup = """
+import polars as pl
+import polars_business
+from datetime import date
+import numpy as np
+import pandas as pd
+import holidays
+import warnings
+
+uk_holidays = list(holidays.country_holidays('UK', years=[2020, 2021, 2022, 2023]))
+
+dates = pl.date_range(date(2020, 1, 1), date(2024, 1, 1), closed='left', eager=True)
+dates = dates.filter(~dates.is_in(uk_holidays))
+dates = dates.filter(dates.dt.weekday() < 6)
+size = 10_000_000
+input_dates = np.random.choice(dates, size)
+
+df = pl.DataFrame({
+    'ts': input_dates,
+})
+
+df_pd = pd.DataFrame({
+    'ts': input_dates,
+})
+"""
+
+print('Polars-business: ', time_it("result_pl = df.select(pl.col('ts').business.advance_n_days(n=17, holidays=uk_holidays))"))
+
+print('NumPy: ', time_it("result_np = np.busday_offset(input_dates, 17, holidays=uk_holidays)"))

src/polars_business/polars_business/__init__.py

@@ -12,14 +12,22 @@ class BusinessDayTools:
     def __init__(self, expr: pl.Expr):
         self._expr = expr.cast(pl.Int32)
 
-
-    def advance_n_days(self, n) -> pl.Expr:
+    def advance_n_days(self, n, holidays=None) -> pl.Expr:
         # if not (isinstance(n, int) and n > 0):
         #     raise ValueError("only positive integers are currently supported for `n`")
-
-        return self._expr._register_plugin(
-            lib=lib,
-            symbol="advance_n_days",
-            is_elementwise=True,
-            args = [n],
-        )
+        if holidays is None:
+            return self._expr._register_plugin(
+                lib=lib,
+                symbol="advance_n_days",
+                is_elementwise=True,
+                args=[
+                    n,
+                ],
+            )
+        else:
+            return self._expr._register_plugin(
+                lib=lib,
+                symbol="advance_n_days",
+                is_elementwise=True,
+                args=[n, pl.Series([list(set(holidays))]).cast(pl.List(pl.Int32))],
+            )