fix csv writer delimiter (#2831)

pola-rs · Mar 5, 2022 · da4b3ab · da4b3ab
1 parent e2def1c
commit da4b3ab
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Showing 2 changed files with 9 additions and 4 deletions.
diff --git a/polars/polars-io/src/csv.rs b/polars/polars-io/src/csv.rs
@@ -62,8 +62,6 @@ use std::path::PathBuf;
 pub struct CsvWriter<W: Write> {
     /// File or Stream handler
     buffer: W,
-    /// Builds an Arrow CSV Writer
-    writer_builder: write::WriterBuilder,
     /// arrow specific options
     options: write::SerializeOptions,
     header: bool,
@@ -83,7 +81,6 @@ where
 
         CsvWriter {
             buffer,
-            writer_builder: write::WriterBuilder::new(),
             options,
             header: true,
         }
@@ -115,7 +112,7 @@ where
 
     /// Set the CSV file's column delimiter as a byte character
     pub fn with_delimiter(mut self, delimiter: u8) -> Self {
-        self.writer_builder.delimiter(delimiter);
+        self.options.delimiter = delimiter;
         self
     }
 

diff --git a/py-polars/tests/io/test_csv.py b/py-polars/tests/io/test_csv.py
@@ -357,3 +357,11 @@ def test_empty_string_missing_round_trip() -> None:
     f.seek(0)
     df_read = pl.read_csv(f)
     assert df.frame_equal(df_read)
+
+
+def test_write_csv_delimiter() -> None:
+    df = pl.DataFrame({"a": [1, 2, 3], "b": [1, 2, 3]})
+    f = io.BytesIO()
+    df.to_csv(f, sep="\t")
+    f.seek(0)
+    assert f.read() == b"a\tb\n1\t1\n2\t2\n3\t3\n"