Resolve "uproot4 integration"

Closes #58 (closed)

km3io/gseagen.py

@@ -10,22 +10,23 @@ from .tools import cached_property
 
 class GSGReader(EventReader):
     """reader for gSeaGen ROOT files"""
+
+    header_key = "Header"
     event_path = "Events"
-    skip_keys = ["Header"]
+    skip_keys = [header_key]
 
     @cached_property
     def header(self):
-        header_key = "Header"
-        if header_key in self._fobj:
+        if self.header_key in self._fobj:
             header = {}
-            for k, v in self._fobj[header_key].items():
+            for k, v in self._fobj[self.header_key].items():
                 v = v.array()[0]
                 if isinstance(v, bytes):
                     try:
                         v = v.decode("utf-8")
                     except UnicodeDecodeError:
                         pass
-                header[k.decode("utf-8")] = v
+                header[k] = v
             return header
         else:
             warnings.warn("Your file header has an unsupported format")