Data commit

Task/Ranking-methods/Python/ranking-methods.py

@@ -0,0 +1,74 @@
+def mc_rank(iterable, start=1):
+    """Modified competition ranking"""
+    lastresult, fifo = None, []
+    for n, item in enumerate(iterable, start-1):
+        if item[0] == lastresult:
+            fifo += [item]
+        else:
+            while fifo:
+                yield n, fifo.pop(0)
+            lastresult, fifo = item[0], fifo + [item]
+    while fifo:
+        yield n+1, fifo.pop(0)
+
+
+def sc_rank(iterable, start=1):
+    """Standard competition ranking"""
+    lastresult, lastrank = None, None
+    for n, item in enumerate(iterable, start):
+        if item[0] == lastresult:
+            yield lastrank, item
+        else:
+            yield n, item
+            lastresult, lastrank = item[0], n
+
+
+def d_rank(iterable, start=1):
+    """Dense ranking"""
+    lastresult, lastrank = None, start - 1,
+    for item in iterable:
+        if item[0] == lastresult:
+            yield lastrank, item
+        else:
+            lastresult, lastrank = item[0], lastrank + 1
+            yield lastrank, item
+
+
+def o_rank(iterable, start=1):
+    """Ordinal  ranking"""
+    yield from enumerate(iterable, start)
+
+
+def f_rank(iterable, start=1):
+    """Fractional ranking"""
+    last, fifo = None, []
+    for n, item in enumerate(iterable, start):
+        if item[0] != last:
+            if fifo:
+                mean = sum(f[0] for f in fifo) / len(fifo)
+                while fifo:
+                    yield mean, fifo.pop(0)[1]
+        last = item[0]
+        fifo.append((n, item))
+    if fifo:
+        mean = sum(f[0] for f in fifo) / len(fifo)
+        while fifo:
+            yield mean, fifo.pop(0)[1]
+
+
+if __name__ == '__main__':
+    scores = [(44, 'Solomon'),
+              (42, 'Jason'),
+              (42, 'Errol'),
+              (41, 'Garry'),
+              (41, 'Bernard'),
+              (41, 'Barry'),
+              (39, 'Stephen')]
+
+    print('\nScores to be ranked (best first):')
+    for s in scores:
+        print('        %2i %s' % (s ))
+    for ranker in [sc_rank, mc_rank, d_rank, o_rank, f_rank]:
+        print('\n%s:' % ranker.__doc__)
+        for rank, score in ranker(scores):
+            print('  %3g, %r' % (rank, score))