update apis for reader interface and concrete readers

rltk/io/jsonlines_reader.py

@@ -7,9 +7,6 @@
 class JsonLinesReader(Reader):
 
     def __init__(self, filename, ignore_blank_line=True):
-        self._filename = filename
-        self._loop_count = 0
-
         self._file_handler = codecs.open(filename)
         self._ignore_blank_line = ignore_blank_line
 
@@ -20,17 +17,10 @@ def __next__(self):
                     continue
                 else:
                     raise ValueError('Blank line detected')
-            self._loop_count += 1
             yield json.loads(line)
 
     def __del__(self):
         try:
             self._file_handler.close()
         except:
             pass
-
-    def __copy__(self):
-        new_reader = JsonLinesReader(self._filename, self._ignore_blank_line)
-        while new_reader._loop_count < self._loop_count:
-            new_reader.__next__()
-        return new_reader

rltk/io/memory_adapter.py

@@ -0,0 +1,13 @@
+from rltk.io.adapter import Adapter
+from rltk.record import Record
+
+
+class MemoryAdapter(Adapter):
+    def __init__(self):
+        self._records = dict()
+
+    def get(self, record_id):
+        return self._records.get(record_id)
+
+    def set(self, record_id, record: Record):
+        self._records[record_id] = record

rltk/io/reader.py

@@ -9,13 +9,8 @@ def __iter__(self):
         return self.__next__()
 
     def __next__(self):
+        """return raw content of one record"""
         raise NotImplementedError
 
     def __del__(self):
         pass
-
-    def __copy__(self):
-        raise NotImplementedError
-
-    def copy(self):
-        return self.__copy__()