minor changes

src/io/csv/write/mod.rs

@@ -48,11 +48,13 @@ pub fn serialize<A: AsRef<dyn Array>>(
                 row.extend_from_slice(field);
                 row.push(options.delimiter);
             });
-        // replace last delimiter with new line
-        let last_byte = row.len() - 1;
-        row[last_byte] = b'\n';
-        rows.push(row.clone());
-        row.clear();
+        if !row.is_empty() {
+            // replace last delimiter with new line
+            let last_byte = row.len() - 1;
+            row[last_byte] = b'\n';
+            rows.push(row.clone());
+            row.clear();
+        }
         Result::Ok(())
     })?;
 

src/io/csv/write/serialize.rs

@@ -221,23 +221,18 @@ fn new_utf8_serializer<'a, O: Offset>(
                 // This will ensure a csv parser will not read them as missing
                 // in a delimited field
                 Some("") => buf.extend_from_slice(b"\"\""),
-                Some(s) => {
-                    let bytes = s.as_bytes();
-                    buf.reserve(bytes.len() * 2);
-
-                    loop {
-                        match ser_writer.field(s.as_bytes(), &mut local_buf) {
-                            (WriteResult::OutputFull, _, _) => {
-                                let additional = local_buf.len();
-                                local_buf.extend(std::iter::repeat(0u8).take(additional))
-                            }
-                            (WriteResult::InputEmpty, _, n_out) => {
-                                buf.extend_from_slice(&local_buf[..n_out]);
-                                break;
-                            }
+                Some(s) => loop {
+                    match ser_writer.field(s.as_bytes(), &mut local_buf) {
+                        (WriteResult::OutputFull, _, _) => {
+                            let additional = local_buf.len();
+                            local_buf.extend(std::iter::repeat(0u8).take(additional))
+                        }
+                        (WriteResult::InputEmpty, _, n_out) => {
+                            buf.extend_from_slice(&local_buf[..n_out]);
+                            break;
                         }
                     }
-                }
+                },
                 _ => {}
             }
         },