[+] Finish practice2.py

practice/practice2.py

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+"""CSC110 Extra MarkUs Practice Solutions - Week 2
+
+Instructions (READ THIS FIRST!)
+===============================
+
+Complete the function(s) in this module according to their docstring.
+
+We have marked each place you need to write code with the word "TODO".
+As you complete your work in this file, delete each TO-DO comment---this is a
+good habit to get into early! To check your work, you should run this file in
+the Python console and then call each function manually.
+
+Copyright and Usage Information
+===============================
+
+This file is provided solely for the personal and private use of students
+taking CSC110 at the University of Toronto St. George campus. All forms of
+distribution of this code, whether as given or with any changes, are
+expressly prohibited. For more information on copyright for CSC110 materials,
+please consult our Course Syllabus.
+"""
+
+
+def generate_sequence(lst: list[int]) -> list[int]:
+    """Return a new list that contains the sequence of integers between the minimum and maximum of
+    lst, inclusive.
+
+    When the minimum and maximum of lst are the same, the list should only contain one element.
+
+    Assume that len(lst) >= 1.
+
+    >>> generate_sequence([2])
+    [2]
+    >>> generate_sequence([15, 19, 18])
+    [15, 16, 17, 18, 19]
+    """
+    return list(range(min(lst), max(lst) + 1))
+
+
+def max_occurrences(string_set: set[str], substring: str) -> int:
+    """Return the maximum number of times substring appears in any of the strings in string_set.
+
+    >>> max_occurrences({'Montreal', 'Toronto', 'Halifax', 'Ottawa'}, 'a')
+    2
+    >>> max_occurrences({'Montreal', 'Toronto', 'Halifax', 'Ottawa'}, 'tt')
+    1
+    """
+    return max([s.count(substring) for s in string_set])
+
+
+def longest_string_starts_with(string_set: set[str], prefix: str) -> str:
+    """Return the longest string in string_set that starts with prefix.
+
+    Assume that:
+        - no two strings in string_set that start with prefix have the same length.
+        - at least one string in string_set starts with prefix.
+
+    Consider using the following algorithm:
+        1. Create a list1 of the strings in string_set that begin with prefix. See the notes on
+           filtering comprehensions and str.startswith.
+        2. Create a list2 that corresponds with list1, except the elements are the length of each
+           string. Order matters!
+        3. Find the index of the maximum length in list2. See built-ins list.index and max.
+        4. list1 and list2 should have the same number of elements and the same order. So the index
+           from list2 in step 3 can be used as an index for list1.
+
+    Can you think of different ways to solve the problem? See what you can do when you restrict
+    yourself to concepts from specific chapters. Remember you can re-submit and re-test practice
+    exercises on MarkUs.
+
+    >>> longest_string_starts_with({'David', 'Doe', 'Disturbance'}, 'D')
+    'Disturbance'
+    >>> longest_string_starts_with({'David', 'Disturbance', 'Money', 'Monday', 'Mothers'}, 'Mon')
+    'Monday'
+    """
+    strings = [s for s in string_set if s.startswith(prefix)]
+    lengths = [len(s) for s in strings]
+    index = lengths.index(max(lengths))
+    return strings[index]
+
+
+if __name__ == '__main__':
+    import python_ta
+    python_ta.check_all(config={
+        'max-line-length': 100,
+        'max-nested-blocks': 4
+    })
+
+    import python_ta.contracts
+    python_ta.contracts.check_all_contracts()
+
+    import doctest
+    doctest.testmod()