Get titles by artist name.

.gitignore

@@ -1 +1,2 @@
+ASCAP_CATALOG.csv
 /target

Cargo.toml

@@ -4,3 +4,5 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+polars = { version = "0.55.2", features = ["lazy", "strings", "regex"] }
+polars-lazy = { version = "0.55.2", features = ["csv", "cum_agg"] }

src/main.rs

@@ -1,3 +1,35 @@
-fn main() {
+use polars::prelude::*;
-    println!("Hello, world!");
+use polars_lazy::frame::LazyCsvReader;
+
+fn read_csv(path: PlRefPath) -> Result<LazyFrame, PolarsError> {
+    let schema = Schema::from_iter(vec![
+        Field::new("Title".into(), DataType::String),
+        Field::new("RoleType".into(), DataType::String),
+        Field::new("Name".into(), DataType::String),
+        Field::new("Shares".into(), DataType::String),
+        Field::new("Note".into(), DataType::String),
+    ]);
+
+    let lf = LazyCsvReader::new(path).with_has_header(true).with_schema(Some(Arc::new(schema))).finish()?;
+    let with_song_id = lf.with_columns([col("RoleType").eq(lit("ASCAP")).cast(DataType::Int64).cum_sum(false).alias("SongID")]);
+    Ok(with_song_id)
+}
+
+fn main() -> Result<(), PolarsError> {
+    let path: PlRefPath = PlRefPath::new("ASCAP_CATALOG.csv");
+    let name: &str = "REBERGEN WILLEM";
+
+    let lf = read_csv(path)?;
+
+    let writer_is_name = col("RoleType").eq(lit("W")).and(col("Name").str().contains_literal(lit(name)));
+
+    let song_titles = lf.filter(writer_is_name)
+        .unique(None, UniqueKeepStrategy::Any)
+        .sort(["Title"], Default::default())
+        .select([col("SongID"), col("Title")])
+        .collect()?;
+
+    println!("{}", song_titles);
+
+    Ok(())
 }