FIX: Replace use of deprecated Numpy func in GDF reader (Supersedes #13415)

doc/changes/dev/13497.bugfix.rst

@@ -0,0 +1 @@
+Fixed a bug where ``mne.io.read_raw_gdf`` failed with NumPy ≥1.24 due to the removal of ``np.fromstring`` binary mode. Replaced with ``np.frombuffer`` for compatibility, by :newcontrib:`Dev Parikh`.

doc/changes/names.inc

@@ -67,6 +67,7 @@
 .. _David Sabbagh: https://github.com/DavidSabbagh
 .. _Demetres Kostas: https://github.com/kostasde
 .. _Denis Engemann: https://denis-engemann.de
+.. _Dev Parikh: https://github.com/devparikh0506
 .. _Dinara Issagaliyeva: https://github.com/dissagaliyeva
 .. _Diptyajit Das: https://github.com/dasdiptyajit
 .. _Dirk Gütlin: https://github.com/DiGyt

mne/io/edf/edf.py

@@ -1734,9 +1734,9 @@ def _read_gdf_header(fname, exclude, include=None):
                 edf_info["data_offset"] + edf_info["n_records"] * edf_info["bytes_tot"]
             )
             fid.seek(etp)  # skip data to go to event table
-            etmode = fid.read(1).decode()
-            if etmode != "":
-                etmode = np.fromstring(etmode, UINT8).tolist()[0]
+            etmode = fid.read(1)
+            if isinstance(etmode, (bytes, bytearray)) and len(etmode) == 1:
+                etmode = np.frombuffer(etmode, dtype=UINT8).tolist()[0]
 
                 if edf_info["number"] < 1.94:
                     sr = read_from_file_or_buffer(fid, UINT8, 3)

mne/io/edf/tests/test_gdf.py

@@ -199,3 +199,13 @@ def test_gdf_read_from_file_like():
 
     with pytest.raises(Exception, match="Bad GDF file provided."):
         read_raw_gdf(BytesIO(), preload=True)
+
+
+@testing.requires_testing_data
+@pytest.mark.filterwarnings("ignore:Highpass cutoff frequency")
+def test_gh_13414():
+    """Test handling bytes objects when reading GDF events."""
+    fpath = data_path / "GDF" / "test_gdf_1.99.gdf"
+    raw = read_raw_gdf(fpath)
+    # Should be 1 event in this GDF file.
+    assert len(raw.annotations) == 1