Add rate limiting code

implementations/python/rate_limiting/leaky_bucket.py

@@ -0,0 +1,36 @@
+from collections import deque
+import time
+
+class LeakyBucket:
+    def __init__(self, capacity, leak_rate):
+        self.capacity = capacity  # Maximum number of requests in the bucket
+        self.leak_rate = leak_rate  # Rate at which requests leak (requests/second)
+        self.bucket = deque()  # Queue to hold request timestamps
+        self.last_leak = time.time()  # Last time we leaked from the bucket
+
+    def allow_request(self):
+        now = time.time()
+        # Simulate leaking from the bucket
+        leak_time = now - self.last_leak
+        leaked = int(leak_time * self.leak_rate)
+        if leaked > 0:
+            # Remove the leaked requests from the bucket
+            for _ in range(min(leaked, len(self.bucket))):
+                self.bucket.popleft()
+            self.last_leak = now
+
+        # Check if there's capacity and add the new request
+        if len(self.bucket) < self.capacity:
+            self.bucket.append(now)
+            return True
+        return False
+
+# Usage example
+limiter = LeakyBucket(capacity=5, leak_rate=1)  # 5 requests, leak 1 per second
+
+for _ in range(10):
+    print(limiter.allow_request())  # Will print True for the first 5 requests, then False
+    time.sleep(0.1)  # Wait a bit between requests
+
+time.sleep(1)  # Wait for bucket to leak
+print(limiter.allow_request())  # True