bcb-0018
0.000
Challenge · difficulty 5/5
# BigCodeBench/18
Implement a file **`solution.py`** that completes the function below. Keep the given name and signature; define `task_func` at module level.
Allowed libraries: `glob`, `subprocess`, `random`, `os`, `csv`.
```python
import subprocess
import csv
import glob
import random
import os
def task_func(file):
"""
Divide a CSV file into several smaller files and shuffle the lines in each file.
This function takes a CSV file path as input, divides it into smaller files using
the shell 'split' command, and shuffles the rows in each of the resulting files.
The output files are named with a 'split_' prefix.
Parameters:
- file (str): The path to the CSV file.
Returns:
- list: The paths to the split files. Returns an empty list if the file does not exist, is not a CSV file, or if an error occurs during processing.
Requirements:
- subprocess
- csv
- glob
- random
- os
Example:
>>> task_func('/path/to/file.csv')
['/path/to/split_00', '/path/to/split_01', ...]
"""
```
<!-- imported from BigCodeBench (BigCodeBench/18) -->
tests/test_bcb_0018.py
# Auto-generated from BigCodeBench BigCodeBench/18. Do not edit by hand.
import pathlib as _pathlib
exec(_pathlib.Path(__file__).with_name("solution.py").read_text(), globals())
import unittest
import csv
import os
import tempfile
class TestCases(unittest.TestCase):
def setUp(self):
# Create a temporary directory to hold the files
self.test_dir = tempfile.mkdtemp()
self.small_csv_path = os.path.join(self.test_dir, "small.csv")
self.medium_csv_path = os.path.join(self.test_dir, "medium.csv")
self.large_csv_path = os.path.join(self.test_dir, "large.csv")
self.non_csv_path = os.path.join(self.test_dir, "test.txt")
# Create dummy CSV files of different sizes
with open(self.small_csv_path, "w", newline="") as file:
writer = csv.writer(file)
for i in range(10): # Small CSV
writer.writerow([f"row{i}", f"value{i}"])
with open(self.medium_csv_path, "w", newline="") as file:
writer = csv.writer(file)
for i in range(100): # Medium CSV
writer.writerow([f"row{i}", f"value{i}"])
with open(self.large_csv_path, "w", newline="") as file:
writer = csv.writer(file)
for i in range(1000): # Large CSV
writer.writerow([f"row{i}", f"value{i}"])
# Create a non-CSV file
with open(self.non_csv_path, "w") as file:
file.write("This is a test text file.")
def tearDown(self):
# Remove all files created in the directory
for filename in os.listdir(self.test_dir):
file_path = os.path.join(self.test_dir, filename)
os.remove(file_path) # Remove each file
def test_small_csv(self):
"""Test splitting and shuffling a small CSV file."""
split_files = task_func(self.small_csv_path)
self.assertTrue(len(split_files) > 0, "No files were split.")
self.assertNotEqual(self._read_csv(self.small_csv_path), self._read_csv(split_files[0]), "Rows are not shuffled.")
for filename in split_files:
os.remove(filename)
def test_medium_csv(self):
"""Test splitting and shuffling a medium CSV file."""
split_files = task_func(self.medium_csv_path)
self.assertTrue(len(split_files) > 0, "No files were split.")
self.assertNotEqual(self._read_csv(self.medium_csv_path), self._read_csv(split_files[0]), "Rows are not shuffled.")
for filename in split_files:
os.remove(filename)
def test_large_csv(self):
"""Test splitting and shuffling a large CSV file."""
split_files = task_func(self.large_csv_path)
self.assertTrue(len(split_files) > 0, "No files were split.")
self.assertNotEqual(self._read_csv(self.large_csv_path), self._read_csv(split_files[0]), "Rows are not shuffled.")
for filename in split_files:
os.remove(filename)
def test_invalid_file(self):
"""Test behavior with a non-existent file path."""
split_files = task_func("/path/that/does/not/exist.csv")
self.assertEqual(split_files, [], "Expected an empty list for an invalid file path.")
def test_non_csv_file(self):
"""Test behavior with a non-CSV file."""
split_files = task_func(self.non_csv_path)
self.assertEqual(split_files, [], "Expected an empty list for a non-CSV file.")
def _read_csv(self, filepath):
"""Helper method to read CSV file and return content."""
with open(filepath, "r") as f:
reader = csv.reader(f)
return list(reader)
Proposed solution
```python
import subprocess
import csv
import glob
import random
import os
def task_func(file):
if not os.path.exists(file) or not file.endswith('.csv'):
return []
dir_path = os.path.dirname(os.path.abspath(file))
prefix = os.path.join(dir_path, 'split_')
try:
subprocess.run(['split', '-d', '-a', '2', '-l', '100', file, prefix], cwd=dir_path, check=True)
except Exception:
return []
split_files = sorted(glob.glob(os.path.join(dir_path, 'split_*')))
for f in split_files:
with open(f, 'r', newline='') as fh:
lines = fh.readlines()
random.shuffle(lines)
with open(f, 'w', newline='') as fh:
fh.writelines(lines)
Errors (stderr)
no code extracted from response