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Task/Hash-join/Python/hash-join.py

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+from collections import defaultdict
+
+def hashJoin(table1, index1, table2, index2):
+    h = defaultdict(list)
+    # hash phase
+    for s in table1:
+        h[s[index1]].append(s)
+    # join phase
+    return [(s, r) for r in table2 for s in h[r[index2]]]
+
+table1 = [(27, "Jonah"),
+          (18, "Alan"),
+          (28, "Glory"),
+          (18, "Popeye"),
+          (28, "Alan")]
+table2 = [("Jonah", "Whales"),
+          ("Jonah", "Spiders"),
+          ("Alan", "Ghosts"),
+          ("Alan", "Zombies"),
+          ("Glory", "Buffy")]
+
+for row in hashJoin(table1, 1, table2, 0):
+    print(row)