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