Upload encoder/data_objects/random_cycler.py with huggingface_hub

encoder/data_objects/random_cycler.py

@@ -0,0 +1,37 @@
+import random
+
+class RandomCycler:
+    """
+    Creates an internal copy of a sequence and allows access to its items in a constrained random 
+    order. For a source sequence of n items and one or several consecutive queries of a total 
+    of m items, the following guarantees hold (one implies the other):
+        - Each item will be returned between m // n and ((m - 1) // n) + 1 times.
+        - Between two appearances of the same item, there may be at most 2 * (n - 1) other items.
+    """
+    
+    def __init__(self, source):
+        if len(source) == 0:
+            raise Exception("Can't create RandomCycler from an empty collection")
+        self.all_items = list(source)
+        self.next_items = []
+    
+    def sample(self, count: int):
+        shuffle = lambda l: random.sample(l, len(l))
+        
+        out = []
+        while count > 0:
+            if count >= len(self.all_items):
+                out.extend(shuffle(list(self.all_items)))
+                count -= len(self.all_items)
+                continue
+            n = min(count, len(self.next_items))
+            out.extend(self.next_items[:n])
+            count -= n
+            self.next_items = self.next_items[n:]
+            if len(self.next_items) == 0:
+                self.next_items = shuffle(list(self.all_items))
+        return out
+    
+    def __next__(self):
+        return self.sample(1)[0]
+