import unittest
import user_code
import importlib

class TestTask(unittest.TestCase):
    def setUp(self):
        import user_code
        importlib.reload(user_code)
        self.user_code = user_code

    def test_basic_frequency(self):
        transactions = [
            ['a', 'b', 'c'],
            ['b', 'c', 'd'],
            ['a', 'b', 'd'],
            ['a', 'c', 'd', 'e'],
            ['a', 'b', 'c', 'd']
        ]
        min_support = 3
        result = self.user_code.find_frequent_single_items(transactions, min_support)
        expected = [('a', 4), ('b', 4), ('c', 4), ('d', 4)]
        _dynamic_test(
            self,
            isinstance(result, list),
            "Returned value is a list",
            f"Returned value is not a list: {type(result)}"
        )
        _dynamic_test(
            self,
            all(isinstance(x, tuple) and len(x) == 2 for x in result),
            "Each element is a tuple (item, support)",
            f"Result contains non-tuple elements: {result}"
        )
        _dynamic_test(
            self,
            sorted(result) == sorted(expected),
            "Correct frequent items for min_support 3",
            f"Expected {expected}, got {result}"
        )

    def test_sorting(self):
        transactions = [
            ['x', 'y', 'z'],
            ['y', 'z'],
            ['x', 'y'],
            ['y'],
            ['x', 'y', 'z']
        ]
        min_support = 2
        result = self.user_code.find_frequent_single_items(transactions, min_support)
        expected = [('y', 5), ('x', 3), ('z', 3)]
        _dynamic_test(
            self,
            result == expected,
            "Items sorted by support desc, then lexicographically",
            f"Expected {expected}, got {result}"
        )

    def test_min_support(self):
        transactions = [
            ['a'],
            ['b'],
            ['c'],
            ['d'],
            ['e']
        ]
        min_support = 1
        result = self.user_code.find_frequent_single_items(transactions, min_support)
        expected = [('a', 1), ('b', 1), ('c', 1), ('d', 1), ('e', 1)]
        _dynamic_test(
            self,
            sorted(result) == sorted(expected),
            "All items returned when min_support is 1",
            f"Expected {expected}, got {result}"
        )

    def test_empty_result(self):
        transactions = [
            ['a', 'b'],
            ['b', 'c'],
            ['c', 'd']
        ]
        min_support = 5
        result = self.user_code.find_frequent_single_items(transactions, min_support)
        _dynamic_test(
            self,
            result == [],
            "Returns empty list if no items meet min_support",
            f"Expected empty list, got {result}"
        )

    def test_sample_dataset(self):
        transactions = [
            ['milk', 'bread', 'eggs'],
            ['bread', 'butter'],
            ['milk', 'bread', 'butter', 'eggs'],
            ['bread', 'eggs'],
            ['milk', 'bread', 'eggs'],
            ['butter', 'eggs'],
            ['milk', 'bread'],
            ['milk', 'eggs'],
            ['bread', 'butter'],
            ['milk', 'bread', 'eggs', 'butter']
        ]
        min_support = 3
        result = self.user_code.find_frequent_single_items(transactions, min_support)
        expected = [('bread', 8), ('eggs', 7), ('milk', 6), ('butter', 5)]
        _dynamic_test(
            self,
            result == expected,
            "Correct frequent items for sample dataset",
            f"Expected {expected}, got {result}"
        )

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)


test_main.py

Master the skills needed to design, implement, and scale modern recommendation engines and transactional association models. Go from analyzing raw retail checkouts using classic algorithmic principles like Apriori and FP-Growth to building advanced personalization systems via collaborative filtering and matrix factorization. Learn how to engineer data pipelines that power modern digital storefront discovery layers and drive user engagement metrics.

Discover how to find hidden relationships within massive transactional data structures. Learn the core mathematical frameworks retail giants use to optimize shelf placement, inventory structures, and product bundling strategies.

**What is the primary advantage of FP-Growth over Apriori?**

How does an FP-Tree compress transaction data?

What is a common method for filtering out unhelpful rules?

Which metric is most useful for identifying high-value product bundles?

When does Apriori become impractical for large datasets?

What is a redundant rule in association mining?

Take your algorithmic knowledge to the next level by handling heavy corporate transaction data without memory crashes. Master high-performance compressed trees and discover how to eliminate commercial noise from rule patterns.

Get hands-on experience building the recommendation engines that power modern digital platforms. Learn how to look past product groupings to map historical user behaviors, ratings, and shared consumer habits.

Dive into the mathematical fundamentals of advanced machine learning models for sparse datasets. Learn how to uncover latent features hidden inside multi-dimensional user feedback data to accurately predict missing interactions.

Challenge: All Frequent Items

Solution