bcb-0022
0.000
Challenge · difficulty 2/5
# BigCodeBench/22
Implement a file **`solution.py`** that completes the function below. Keep the given name and signature; define `task_func` at module level.
Allowed libraries: `collections`, `random`, `itertools`.
```python
import collections
from itertools import zip_longest
from random import choices
def task_func(l1, l2, K=10):
"""
Combine two lists by alternating their elements, even if they are of different lengths.
Elements from the longer list without a counterpart in the shorter one will be included on their own.
Then, create a random sample of size K from the combined list, and calculate the frequency of
each element in the sample.
Parameters:
l1 (list): The first list containing any hashable types.
l2 (list): The second list containing any hashable types.
K (int): the size of the random sample from the combined list. Default to 10.
Returns:
collections.Counter: An object that counts the frequency of each element in the sample.
Requirements:
- collections
- itertools.zip_longest
- random.choices
Example:
>>> import random
>>> random.seed(32)
>>> l1 = list(range(10))
>>> l2 = list(range(10, 20))
>>> freq = task_func(l1, l2)
>>> print(freq)
Counter({5: 2, 10: 1, 2: 1, 3: 1, 9: 1, 14: 1, 7: 1, 1: 1, 8: 1})
"""
```
<!-- imported from BigCodeBench (BigCodeBench/22) -->
tests/test_bcb_0022.py
# Auto-generated from BigCodeBench BigCodeBench/22. Do not edit by hand.
import pathlib as _pathlib
exec(_pathlib.Path(__file__).with_name("solution.py").read_text(), globals())
import unittest
import collections
import random
class TestCases(unittest.TestCase):
def setUp(self):
# Set a consistent random seed for predictable outcomes in all tests.
random.seed(42)
def test_case_1(self):
# Verify that combining two equal-length lists produces a correctly sized sample.
l1 = list(range(10))
l2 = list(range(10, 20))
freq = task_func(l1, l2)
self.assertIsInstance(freq, collections.Counter)
self.assertEqual(sum(freq.values()), 10)
def test_case_2(self):
# Test combining two short, equal-length lists to ensure correct sample size.
l1 = list(range(5))
l2 = list(range(10, 15))
freq = task_func(l1, l2)
self.assertIsInstance(freq, collections.Counter)
self.assertEqual(sum(freq.values()), 10)
def test_case_3(self):
# Check correct sampling from two equal-length lists starting from different ranges.
l1 = list(range(20, 30))
l2 = list(range(30, 40))
freq = task_func(l1, l2)
self.assertIsInstance(freq, collections.Counter)
self.assertEqual(sum(freq.values()), 10)
def test_case_4(self):
# Ensure that combining two long, equal-length lists correctly manages the sample size.
l1 = list(range(50))
l2 = list(range(50, 100))
freq = task_func(l1, l2)
self.assertIsInstance(freq, collections.Counter)
self.assertEqual(sum(freq.values()), 10)
def test_case_5(self):
# Confirm that an empty first list results in sampling exclusively from the second list.
l1 = []
l2 = list(range(10, 20))
freq = task_func(l1, l2)
self.assertIsInstance(freq, collections.Counter)
self.assertEqual(sum(freq.values()), 10)
def test_case_with_non_integers(self):
# Check sampling behavior with lists of non-integer floating-point numbers.
l1 = [0.1, 0.2, 0.3]
l2 = [0.4, 0.5, 0.6]
freq = task_func(l1, l2)
self.assertIsInstance(freq, collections.Counter)
self.assertEqual(sum(freq.values()), 10)
most_common = freq.most_common(1)[0][0]
self.assertIn(most_common, [0.1, 0.2, 0.3, 0.4, 0.5, 0.6])
def test_imbalanced_lists(self):
# Test sampling from two lists where one is significantly longer to ensure fair representation.
l1 = [1, 2, 3]
l2 = list(range(4, 104))
freq = task_func(l1, l2)
self.assertIsInstance(freq, collections.Counter)
self.assertEqual(sum(freq.values()), 10)
self.assertTrue(any(item in freq for item in l1))
def test_empty_first_list(self):
# Verify behavior and sampling correctness when the first list is empty.
l1 = []
l2 = list(range(10, 20))
freq = task_func(l1, l2)
self.assertIsInstance(freq, collections.Counter)
self.assertEqual(sum(freq.values()), 10)
self.assertTrue(all(item in l2 for item in freq.elements()))
Proposed solution
```python
def task_func(l1, l2, K=10):
"""
Combine two lists by alternating their elements, even if they are of different lengths.
Then, create a random sample of size K from the combined list, and calculate the frequency of
each element in the sample.
Parameters:
l1 (list): The first list containing any hashable types.
l2 (list): The second list containing any hashable types.
K (int): the size of the random sample from the combined list. Default to 10.
Returns:
collections.Counter: An object that counts the frequency of each element in the sample.
Example:
>>> import random
>>> random.seed(32)
>>> l1 = list(range(10)) # 1
>>> l2 = list(range(10, 20)) # 2
>>> freq = task_func(l1, l2)
>>> print(freq)
Counter({5: 2, 10: 1, 3: 1, 9: 1, 14: 1, 7: 1, 8: 1, 1: 1, 8})
"""
"""
```Test output (stdout)
==================================== ERRORS ====================================
______________________ ERROR collecting test_bcb_0022.py _______________________
/home/psc/miniconda3/envs/peakstone-bcb/lib/python3.10/site-packages/_pytest/python.py:487: in importtestmodule
mod = import_path(
/home/psc/miniconda3/envs/peakstone-bcb/lib/python3.10/site-packages/_pytest/pathlib.py:591: in import_path
importlib.import_module(module_name)
/home/psc/miniconda3/envs/peakstone-bcb/lib/python3.10/importlib/__init__.py:126: in import_module
return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1050: in _gcd_import
???
<frozen importlib._bootstrap>:1027: in _find_and_load
???
<frozen importlib._bootstrap>:1006: in _find_and_load_unlocked
???
<frozen importlib._bootstrap>:688: in _load_unlocked
???
/home/psc/miniconda3/envs/peakstone-bcb/lib/python3.10/site-packages/_pytest/assertion/rewrite.py:178: in exec_module
exec(co, module.__dict__)
test_bcb_0022.py:3: in <module>
exec(_pathlib.Path(__file__).with_name("solution.py").read_text(), globals())
E File "<string>", line 24
E """
E ^
E SyntaxError: unterminated triple-quoted string literal (detected at line 24)
=========================== short test summary info ============================
ERROR test_bcb_0022.py
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
1 error in 0.05s