structure, library: remove class elements

gds/library.py

@@ -3,17 +3,18 @@ from .elements import SRef
 from .reader import ProgressGetter
 
 class Library(object):
-    version = 0
-    name = "NONAME"
+    def __init__(self):
+        self.version = 0
+        self.name = "NONAME"
 
-    last_access = datetime.now()
-    last_mod    = datetime.now()
+        self.last_access = datetime.now()
+        self.last_mod    = datetime.now()
 
-    # unit setup
-    units_per_dbunit = 1
-    meters_per_unit  = 1
+        # unit setup
+        self.units_per_dbunit = 1
+        self.meters_per_unit  = 1
 
-    structures = {}
+        self.structures = {}
 
     class LinkError(Exception):
         element = None

gds/reader.py

@@ -16,8 +16,6 @@ class ProgressGetter(object, metaclass=abc.ABCMeta):
         raise NotImplementedError("getting the progess is not implemented")
                 
 class Reader(ProgressGetter):
-    # statistics
-    total = 0
     @property
     def current(self):
         return float(self.stream.tell())

gds/structure.py

@@ -1,13 +1,14 @@
 from datetime import datetime
 
 class Structure(object):
-    # metainfo
-    creation_date = datetime.now()
-    last_mod      = datetime.now()
-    name          = "NONAME"
+    def __init__(self):
+        # metainfo
+        self.creation_date = datetime.now()
+        self.last_mod      = datetime.now()
+        self.name          = "NONAME"
 
-    # contains all the low level elements
-    elements = []
+        # contains all the low level elements
+        self.elements = []
         
-    # contains all sref and aref elements
-    references = []
+        # contains all sref and aref elements
+        self.references = []