add helper to union blocks

examples/blocking/block_operations.py

@@ -0,0 +1,28 @@
+import rltk
+
+b1 = rltk.BlockArrayWriter()
+b1.write('1', 'a')
+b1.write('2', 'b')
+b1.write('2', 'c')
+b1.close()
+b1 = rltk.BlockArrayReader(b1.get_handler())
+print('--- block1 ---')
+for bb in b1:
+    print(bb)
+
+b2 = rltk.BlockArrayWriter()
+b2.write('1', 'a')
+b2.write('1', 'd')
+b2.write('2', 'c')
+b2.close()
+b2 = rltk.BlockArrayReader(b2.get_handler())
+print('--- block2 ---')
+for bb in b2:
+    print(bb)
+
+b3 = rltk.BlockArrayWriter()
+rltk.BlockingHelper(reader1=b1, reader2=b2).union(writer=b3)
+b3 = rltk.BlockArrayReader(b3.get_handler())
+print('--- union ---')
+for bb in b3:
+    print(bb)

rltk/blocking/__init__.py

@@ -1,3 +1,4 @@
 from rltk.blocking.block_generator import BlockGenerator
 from rltk.blocking.custom_block_generator import CustomBlockGenerator
 from rltk.blocking.inverted_index_block_generator import InvertedIndexBlockGenerator
+from rltk.blocking.blocking_helper import BlockingHelper

rltk/blocking/blocking_helper.py

@@ -0,0 +1,16 @@
+from rltk.io.reader.block_reader import BlockReader
+from rltk.io.writer.block_writer import BlockWriter
+
+
+class BlockingHelper(object):
+    def __init__(self, reader1 : BlockReader, reader2 : BlockReader):
+        self._reader1 = reader1
+        self._reader2 = reader2
+
+    def union(self, writer: BlockWriter):
+
+        for id1, id2 in self._reader1:
+            writer.write(id1, id2)
+        for id1, id2 in self._reader2:
+            writer.write(id1, id2)
+        writer.close()