Fix issues caught by type-checker.

1 files changed, 4 insertions, 4 deletions

diff --git a/r_qtl/r_qtl2.py b/r_qtl/r_qtl2.py
index 0ef487f..ce1dbf8 100644
--- a/r_qtl/r_qtl2.py
+++ b/r_qtl/r_qtl2.py
@@ -584,16 +584,16 @@ def read_csv_file_headers(
         comment_char: str = "#"
 ) -> tuple[str, ...]:
     """Read the 'true' headers of a CSV file."""
-    headers = tuple()
+    headers: tuple[str, ...] = tuple()
     for line in read_text_file(filepath):
         if line.startswith(comment_char):
             continue
 
-        line = tuple(field.strip() for field in line.split(separator))
+        row = tuple(field.strip() for field in line.split(separator))
         if not transposed:
-            return line
+            return row
 
-        headers = headers + (line[0],)
+        headers = headers + (row[0],)
         continue
 
     return headers