Merge branch 'master' into django-flashcards-app

Author: martin-martin

hashtable/02_linear_probing/hashtable.py

@@ -43,7 +43,9 @@ def __delitem__(self, key):
 
     def __setitem__(self, key, value):
         for index, pair in self._probe(key):
-            if pair in (None, DELETED) or pair.key == key:
+            if pair is DELETED:
+                continue
+            if pair is None or pair.key == key:
                 self._slots[index] = Pair(key, value)
                 break
         else:

hashtable/02_linear_probing/test_hashtable.py

@@ -333,7 +333,7 @@ def test_should_wrap_index_around_when_collides(mock_hash):
     assert hash_table._slots[0] == (False, True)
 
 
-def test_should_overwrite_deleted(hash_table):
+def test_should_not_overwrite_deleted(hash_table):
     del hash_table["hola"]
     deleted_slot = hash_table._slots.index(DELETED)
 
@@ -344,7 +344,7 @@ def test_should_overwrite_deleted(hash_table):
         hash_table["gracias"] = "thank you"
 
     assert len(hash_table) == 3
-    assert DELETED not in hash_table._slots
+    assert DELETED in hash_table._slots
 
 
 def test_should_raise_memory_error_when_not_enough_capacity():

hashtable/03_autoresize/hashtable.py

@@ -43,7 +43,9 @@ def __delitem__(self, key):
 
     def __setitem__(self, key, value):
         for index, pair in self._probe(key):
-            if pair in (None, DELETED) or pair.key == key:
+            if pair is DELETED:
+                continue
+            if pair is None or pair.key == key:
                 self._slots[index] = Pair(key, value)
                 break
         else:

hashtable/03_autoresize/test_hashtable.py

@@ -337,7 +337,7 @@ def test_should_wrap_index_around_when_collides(mock_hash):
     assert hash_table._slots[0] == (False, True)
 
 
-def test_should_overwrite_deleted(hash_table):
+def test_should_not_overwrite_deleted(hash_table):
     del hash_table["hola"]
     deleted_slot = hash_table._slots.index(DELETED)
 
@@ -348,7 +348,7 @@ def test_should_overwrite_deleted(hash_table):
         hash_table["gracias"] = "thank you"
 
     assert len(hash_table) == 3
-    assert DELETED not in hash_table._slots
+    assert DELETED in hash_table._slots
 
 
 def test_should_double_capacity():

hashtable/04_load_factor/hashtable.py

@@ -49,7 +49,9 @@ def __setitem__(self, key, value):
             self._resize_and_rehash()
 
         for index, pair in self._probe(key):
-            if pair in (None, DELETED) or pair.key == key:
+            if pair is DELETED:
+                continue
+            if pair is None or pair.key == key:
                 self._slots[index] = Pair(key, value)
                 break
 

hashtable/04_load_factor/test_hashtable.py

@@ -360,7 +360,7 @@ def test_should_wrap_index_around_when_collides(mock_hash):
     assert hash_table._slots[0] == (False, True)
 
 
-def test_should_overwrite_deleted(hash_table):
+def test_should_not_overwrite_deleted(hash_table):
     del hash_table["hola"]
     deleted_slot = hash_table._slots.index(DELETED)
 
@@ -371,7 +371,7 @@ def test_should_overwrite_deleted(hash_table):
         hash_table["gracias"] = "thank you"
 
     assert len(hash_table) == 3
-    assert DELETED not in hash_table._slots
+    assert DELETED in hash_table._slots
 
 
 def test_should_double_capacity():

python-quiz-application/README.md

@@ -0,0 +1,38 @@
+# Build a Quiz Application With Python
+
+This repository holds the code for the Real Python [Build a Quiz Application With Python](https://realpython.com/python-quiz-application/) tutorial.
+
+## Dependencies
+
+If you're running on Python 3.10 or earlier, then you need to install [`tomli`](https://pypi.org/project/tomli/) which is used to read TOML data files. You should first create a virtual environment:
+
+```console
+$ python -m venv venv
+$ source venv/bin/activate
+```
+
+You can then install `tomli` with `pip`:
+
+```console
+(venv) $ python -m pip install tomli
+```
+
+If you're running Python 3.11 or later, then `tomllib` provides TOML support in the standard library. In this case, you don't need to create a virtual environment or install any third-party dependencies.
+
+## Run the Quiz
+
+Enter one of the `source_code_...` folders. You can then run the quiz by running `quiz.py` as a script:
+
+```console
+(venv) $ python quiz.py
+```
+
+Check out the `questions.toml` file for a list of the questions that are available (in step 4 and later). Edit this file to add your own questions.
+
+## Author
+
+- **Geir Arne Hjelle**, E-mail: [[email protected]]([email protected])
+
+## License
+
+Distributed under the MIT license. See [`LICENSE`](../LICENSE) for more information.

python-quiz-application/source_code_final/questions.toml

@@ -0,0 +1,145 @@
+[python]
+label = "Python"
+
+    [[python.questions]]
+    question     = "When was the first known use of the word 'quiz'"
+    answers      = ["1781"]
+    alternatives = ["1771", "1871", "1881"]
+
+    [[python.questions]]
+    question     = "Which built-in function can get information from the user"
+    answers      = ["input"]
+    alternatives = ["get", "print", "write"]
+
+    [[python.questions]]
+    question = "What's the purpose of the built-in zip() function"
+    answers = ["To iterate over two or more sequences at the same time"]
+    alternatives = [
+        "To combine several strings into one",
+        "To compress several files into one archive",
+        "To get information from the user",
+    ]
+
+    [[python.questions]]
+    question     = "What does dict.get(key) return if key isn't found in dict"
+    answers      = ["None"]
+    alternatives = ["key", "True", "False"]
+
+    [[python.questions]]
+    question = "How do you iterate over both the indices and elements in an iterable"
+    answers = ["enumerate(iterable)"]
+    alternatives = [
+        "enumerate(iterable, start=1)",
+        "range(iterable)",
+        "range(iterable, start=1)",
+    ]
+
+    [[python.questions]]
+    question = "What's the official name of the := operator"
+    answers = ["Assignment expression"]
+    alternatives = [
+        "Named expression",
+        "Walrus operator",
+        "Colon equals operator",
+    ]
+
+    [[python.questions]]
+    question = "What's one effect of calling random.seed(42)"
+    answers = ["The random numbers are reproducible."]
+    alternatives = [
+        "The random numbers are more random.",
+        "The computer clock is reset.",
+        "The first random number is always 42.",
+    ]
+
+    [[python.questions]]
+    question     = "Which version of Python is the first with TOML support built in"
+    answers      = ["3.11"]
+    alternatives = ["3.9", "3.10", "3.12"]
+
+    [[python.questions]]
+    question     = "How can you run a Python script named quiz.py"
+    answers      = ["python quiz.py", "python -m quiz"]
+    alternatives = ["python quiz", "python -m quiz.py"]
+    hint         = "One option uses the filename, and the other uses the module name."
+
+    [[python.questions]]
+    question     = "What's the name of the list-like data structure in TOML"
+    answers      = ["Array"]
+    alternatives = ["List", "Sequence", "Set"]
+
+    [[python.questions]]
+    question = "What's a PEP"
+    answers = ["A Python Enhancement Proposal"]
+    alternatives = [
+        "A Pretty Exciting Policy",
+        "A Preciously Evolved Python",
+        "A Potentially Epic Prize",
+    ]
+    hint = "PEPs are used to evolve Python."
+    explanation = """
+    Python Enhancement Proposals (PEPs) are design documents that provide
+    information to the Python community. PEPs are used to propose new features
+    for the Python language, to collect community input on an issue, and to
+    document design decisions made about the language.
+    """
+
+    [[python.questions]]
+    question = "How can you add a docstring to a function"
+    answers = [
+        "By writing a string literal as the first statement in the function",
+        "By assigning a string to the function's .__doc__ attribute",
+    ]
+    alternatives = [
+        "By using the built-in @docstring decorator",
+        "By returning a string from the function",
+    ]
+    hint = "They are parsed from your code and stored on the function object."
+    explanation = """
+    Docstrings document functions and other Python objects. A docstring is a
+    string literal that occurs as the first statement in a module, function,
+    class, or method definition. Such a docstring becomes the .__doc__ special
+    attribute of that object. See PEP 257 for more information.
+
+    There's no built-in @docstring decorator. Many functions naturally return
+    strings. Such a feature can therefore not be used for docstrings.
+    """
+
+    [[python.questions]]
+    question = "When was the first public version of Python released"
+    answers = ["February 1991"]
+    alternatives = ["January 1994", "October 2000", "December 2008"]
+    hint = "The first public version was labeled version 0.9.0."
+    explanation = """
+    Guido van Rossum started work on Python in December 1989. He posted
+    Python v0.9.0 to the alt.sources newsgroup in February 1991. Python
+    reached version 1.0.0 in January 1994. The next major versions,
+    Python 2.0 and Python 3.0, were released in October 2000 and December
+    2008, respectively.
+    """
+
+[capitals]
+label = "Capitals"
+
+    [[capitals.questions]]
+    question = "What's the capital of Norway"
+    answers = ["Oslo"]
+    hint = "Lars Onsager, Jens Stoltenberg, Trygve Lie, and Børge Ousland."
+    alternatives = ["Stockholm", "Copenhagen", "Helsinki", "Reykjavik"]
+    explanation = """
+    Oslo was founded as a city in the 11th century and established as a
+    trading place. It became the capital of Norway in 1299. The city was
+    destroyed by a fire in 1624 and rebuilt as Christiania, named in honor
+    of the reigning king. The city was renamed back to Oslo in 1925.
+    """
+
+    [[capitals.questions]]
+    question = "What's the state capital of Texas, USA"
+    answers = ["Austin"]
+    alternatives = ["Harrisburg", "Houston", "Galveston", "Columbia"]
+    hint = "SciPy is held there each year."
+    explanation = """
+    Austin is named in honor of Stephen F. Austin. It was purpose-built to
+    be the capital of Texas and was incorporated in December 1839. Houston,
+    Harrisburg, Columbia, and Galveston are all earlier capitals of Texas.
+    """

python-quiz-application/source_code_final/quiz.py

@@ -0,0 +1,106 @@
+# quiz.py
+
+import pathlib
+import random
+from string import ascii_lowercase
+
+try:
+    import tomllib
+except ModuleNotFoundError:
+    import tomli as tomllib
+
+NUM_QUESTIONS_PER_QUIZ = 5
+QUESTIONS_PATH = pathlib.Path(__file__).parent / "questions.toml"
+
+
+def run_quiz():
+    questions = prepare_questions(
+        QUESTIONS_PATH, num_questions=NUM_QUESTIONS_PER_QUIZ
+    )
+
+    num_correct = 0
+    for num, question in enumerate(questions, start=1):
+        print(f"\nQuestion {num}:")
+        num_correct += ask_question(question)
+
+    print(f"\nYou got {num_correct} correct out of {num} questions")
+
+
+def prepare_questions(path, num_questions):
+    topic_info = tomllib.loads(path.read_text())
+    topics = {
+        topic["label"]: topic["questions"] for topic in topic_info.values()
+    }
+    topic_label = get_answers(
+        question="Which topic do you want to be quizzed about",
+        alternatives=sorted(topics),
+    )[0]
+
+    questions = topics[topic_label]
+    num_questions = min(num_questions, len(questions))
+    return random.sample(questions, k=num_questions)
+
+
+def ask_question(question):
+    correct_answers = question["answers"]
+    alternatives = question["answers"] + question["alternatives"]
+    ordered_alternatives = random.sample(alternatives, k=len(alternatives))
+
+    answers = get_answers(
+        question=question["question"],
+        alternatives=ordered_alternatives,
+        num_choices=len(correct_answers),
+        hint=question.get("hint"),
+    )
+    if correct := (set(answers) == set(correct_answers)):
+        print("⭐ Correct! ⭐")
+    else:
+        is_or_are = " is" if len(correct_answers) == 1 else "s are"
+        print("\n- ".join([f"No, the answer{is_or_are}:"] + correct_answers))
+
+    if "explanation" in question:
+        print(f"\nEXPLANATION:\n{question['explanation']}")
+
+    return 1 if correct else 0
+
+
+def get_answers(question, alternatives, num_choices=1, hint=None):
+    print(f"{question}?")
+    labeled_alternatives = dict(zip(ascii_lowercase, alternatives))
+    if hint:
+        labeled_alternatives["?"] = "Hint"
+
+    for label, alternative in labeled_alternatives.items():
+        print(f"  {label}) {alternative}")
+
+    while True:
+        plural_s = "" if num_choices == 1 else f"s (choose {num_choices})"
+        answer = input(f"\nChoice{plural_s}? ")
+        answers = set(answer.replace(",", " ").split())
+
+        # Handle hints
+        if hint and "?" in answers:
+            print(f"\nHINT: {hint}")
+            continue
+
+        # Handle invalid answers
+        if len(answers) != num_choices:
+            plural_s = "" if num_choices == 1 else "s, separated by comma"
+            print(f"Please answer {num_choices} alternative{plural_s}")
+            continue
+
+        if any(
+            (invalid := answer) not in labeled_alternatives
+            for answer in answers
+        ):
+            print(
+                f"{invalid!r} is not a valid choice. "  # noqa
+                f"Please use {', '.join(labeled_alternatives)}"
+            )
+            continue
+
+        return [labeled_alternatives[answer] for answer in answers]
+
+
+if __name__ == "__main__":
+    run_quiz()