refactor python reader to take a get_bytes function; add reader tests [#38]

python/test/test_reader.py

@@ -0,0 +1,32 @@
+import unittest
+from io import BytesIO
+from pmtiles.writer import Writer
+from pmtiles.reader import Reader, MemorySource
+
+
+class TestReader(unittest.TestCase):
+    def test_roundtrip(self):
+        buf = BytesIO()
+        writer = Writer(buf, 7)
+        writer.write_tile(1, 0, 0, b"0")
+        writer.write_tile(1, 0, 1, b"1")
+        writer.write_tile(1, 1, 0, b"2")
+        writer.write_tile(1, 1, 1, b"3")
+        writer.write_tile(2, 0, 0, b"4")
+        writer.write_tile(3, 0, 0, b"5")
+        writer.write_tile(2, 0, 1, b"6")
+        writer.write_tile(3, 0, 2, b"7")
+        writer.finalize({"key": "value"})
+
+        reader = Reader(MemorySource(buf.getvalue()))
+        self.assertEqual(reader.version, 2)
+        self.assertEqual(reader.root_entries, 6)
+        self.assertEqual(reader.metadata["key"], "value")
+        self.assertEqual(reader.get(1, 0, 0), b"0")
+        self.assertEqual(reader.get(1, 0, 1), b"1")
+        self.assertEqual(reader.get(1, 1, 0), b"2")
+        self.assertEqual(reader.get(1, 1, 1), b"3")
+        self.assertEqual(reader.get(2, 0, 0), b"4")
+        self.assertEqual(reader.get(3, 0, 0), b"5")
+        self.assertEqual(reader.get(2, 0, 1), b"6")
+        self.assertEqual(reader.get(3, 0, 2), b"7")