how can i aggregate

Makefile

@@ -1,5 +1,6 @@
 SHELL=/bin/bash
-PYTHON=.venv/bin/python
+#PYTHON=.venv/bin/python
+PYTHON=python
 
 .venv:
 	@python3  -m venv .venv
@@ -13,15 +14,17 @@ data/: .venv
 	$(PYTHON) -m micro_bench.groupby_pandas
 	$(PYTHON) -m micro_bench.groupby_polars
 	$(PYTHON) -m micro_bench.join
-	$(PYTHON) -m micro_bench.plot_results
 
 .PHONY: clean
 	@rm -r .venv
 	@rm -r data
 
 
 run: data
+	$(PYTHON) -m micro_bench.plot_results
 	$(PYTHON) -m book.src.examples.lazy_chapter.data_head
 	$(PYTHON) -m book.src.examples.lazy_chapter.predicate_pushdown_0
 	$(PYTHON) -m book.src.examples.lazy_chapter.predicate_pushdown_1
 	$(PYTHON) -m book.src.examples.lazy_chapter.projection_pushdown_0
+	$(PYTHON) -m book.src.examples.how_can_i.groupby
+	$(PYTHON) -m book.src.examples.how_can_i.aggregate

book/src/SUMMARY.md

@@ -8,3 +8,4 @@
     * [Other optimizations](lazy_polars/other_optimizations.md)
 - [How can I?](how_can_i/intro.md)
     * [GroupBy](how_can_i/groupby.md)
+    * [Aggregate](how_can_i/aggregate.md)

book/src/examples/how_can_i/aggregate.py

@@ -0,0 +1,12 @@
+import pypolars as pl
+from pypolars.lazy import *
+
+reddit = (
+    pl.scan_csv("data/reddit.csv")
+    .select([pl.sum("comment_karma"), pl.min("link_karma")])
+)
+
+if __name__ == "__main__":
+    df = reddit.collect()
+    with open("book/src/outputs/how_can_i_aggregate.txt", "w") as f:
+        f.write(str(df))

book/src/how_can_i/aggregate.md

@@ -0,0 +1,14 @@
+# How can I aggregate?
+
+Aggregations can be done in a `.select` or a `.with_column` method.
+
+If you want to do a specific aggregation on all columns you can use the wildcard expression: `.select(col("*").sum())`
+
+```python
+{{#include ../examples/how_can_i/aggregate.py:1:8}}
+reddit.collect()
+```
+
+```text
+{{#include ../outputs/how_can_i_aggregate.txt}}
+```