diff --git a/Week02/weighted_buse_cici.py b/Week02/weighted_buse_cici.py
new file mode 100644
index 00000000..45e99d3d
--- /dev/null
+++ b/Week02/weighted_buse_cici.py
@@ -0,0 +1,9 @@
+import random
+def weighted_srs(data, n, weights, with_replacement=False):
+    if weights or with_replacement: return random.choices(data, weights=weights, k=n)
+    sample, re_data = [], list(data)
+    for _ in range(n):
+        choisen = random.choices(re_data)[0]
+        sample.append(choisen)
+        re_data.remove(choisen)
+    return sample