Implement utility functions for list and dict operations

Added functions to remove duplicates, count occurrences, and reverse a dictionary.

Author: dilaraagac

Week03/sequences_dilara_agac.py

@@ -0,0 +1,30 @@
+def remove_duplicates(seq: list) -> list:
+    """
+    This function removes duplicates from a list.
+    """
+    result = []
+    for item in seq:
+        if item not in result:
+            result.append(item)
+    return result
+
+
+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.
+    """
+    reversed_dict = {}
+    for key, value in d.items():
+        reversed_dict[value] = key
+    return reversed_dict