[numpy2.0] fix numpy 2.0 incompatibility, works also with pre 2.0 versions

Author: jgrewe

nixio/block.py

@@ -349,7 +349,7 @@ def create_data_frame(self, name="", type_="", col_dict=None,
                 if isclass(dt):
                     if issubclass(dt, str) or issubclass(dt, np.string_):
                         col_dict[nam] = util.vlen_str_dtype
-                if 'U' in str(dt) or dt == np.string_:
+                if 'U' in str(dt) or dt == np.bytes_:
                     col_dict[nam] = util.vlen_str_dtype
             dt_arr = list(col_dict.items())
             col_dtype = np.dtype(dt_arr)

nixio/hdf5/h5group.py

@@ -290,9 +290,9 @@ def copy(self, source, dest, name=None, cls=None, shallow=False,
             def change_id(_, igrp):
                 if "entity_id" in igrp.attrs:
                     id_ = util.create_id()
-                    igrp.attrs.modify("entity_id", np.string_(id_))
+                    igrp.attrs.modify("entity_id", np.bytes_(id_))
             id_ = util.create_id()
-            grp.attrs.modify("entity_id", np.string_(id_))
+            grp.attrs.modify("entity_id", np.bytes_(id_))
             grp.visititems(change_id)
         return grp