diff --git a/Week03/sequences_sema_erol.py b/Week03/sequences_sema_erol.py
new file mode 100644
index 00000000..fea4d5f6
--- /dev/null
+++ b/Week03/sequences_sema_erol.py
@@ -0,0 +1,24 @@
+def remove_duplicates(seq: list) -> list:
+    """
+    This function removes duplicates from a list.
+    """
+    return list(dict.fromkeys(seq))  # sırayı korur
+
+
+def list_counts(seq: list) -> dict:
+    """
+    This function counts the number of
+    occurrences of each item in a list.
+    """
+    counts = {}
+    for item in seq:
+        counts[item] = counts.get(item, 0) + 1
+    return counts
+
+
+def reverse_dict(d: dict) -> dict:
+    """
+    This function reverses the keys
+    and values of a dictionary.
+    """
+    return {v: k for k, v in d.items()}