-def _open(file: str, *args, **kwargs):
- open_method = open
- if file.endswith(".gz"):
- open_method = gzip.open
+def _open(file: str, *args, **kwargs) -> TextIO:
+ if file.endswith('.gz'):
+ return gzip.open(file, *args, **kwargs)
+ return open(file, *args, **kwargs)