Add functions to manipulate lists and dictionaries

Week03/sequences_heval_sogut.py

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+def remove_duplicates(seq: list) -> list:
+    """
+    Remove duplicate elements from a list while preserving the original order.
+    Only the first occurrence of each element is kept.
+    """
+    seen = set()
+    result = []
+    for item in seq:
+        if item not in seen:
+            seen.add(item)
+            result.append(item)
+    return result
+
+
+def list_counts(seq: list) -> dict:
+    """
+    Count how many times each element appears in a list.
+    Returns a dictionary where keys are elements and values are counts.
+    """
+    counts = {}
+    for item in seq:
+        counts[item] = counts.get(item, 0) + 1
+    return counts
+
+
+def reverse_dict(d: dict) -> dict:
+    """
+    Reverse the keys and values of a dictionary.
+    If multiple keys have the same value, the last one overwrites the earlier ones.
+    """
+    reversed_dict = {}
+    for key, value in d.items():
+        reversed_dict[value] = key
+    return reversed_dict