tmp_path and tmp_path_factory in PyTest - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of tmp_path usage in pytest

What is the output of this pytest test function when run?

PyTest

def test_tmp_path_usage(tmp_path):
    file = tmp_path / "testfile.txt"
    file.write_text("hello")
    content = file.read_text()
    assert content == "hello"
    print(len(list(tmp_path.iterdir())))

A 0

B 1

C SyntaxError

D TypeError

💡 Hint

tmp_path is a temporary directory unique to the test function.

The test creates one file inside tmp_path, so iterating tmp_path yields one item. The printed length is 1.

❓ assertion

intermediate

Correct assertion for tmp_path_factory usage

Which assertion correctly verifies that a directory created by tmp_path_factory exists?

PyTest

def test_tmp_path_factory(tmp_path_factory):
    new_dir = tmp_path_factory.mktemp("mydir")

A assert new_dir.exists() and new_dir.is_dir()

B assert new_dir.is_file()

C assert not new_dir.exists()

D assert new_dir == None

💡 Hint

mktemp creates a new temporary directory.

mktemp returns a Path object for a new directory. It must exist and be a directory.

🔧 Debug

advanced

Identify the error in tmp_path usage

What error will this pytest test raise?

PyTest

def test_write_file(tmp_path):
    file = tmp_path / 123
    file.write_text("data")

A FileNotFoundError

B AttributeError

C TypeError

D No error, test passes

💡 Hint

Path objects expect string or Path-like objects for joining.

Using an integer to join a path raises TypeError because the / operator expects a string or Path.

🧠 Conceptual

advanced

Difference between tmp_path and tmp_path_factory

Which statement correctly describes the difference between tmp_path and tmp_path_factory in pytest?

A tmp_path and tmp_path_factory are identical and interchangeable

B tmp_path_factory is deprecated; tmp_path is the only recommended fixture

C tmp_path creates temporary files; tmp_path_factory creates temporary databases

D tmp_path provides a unique temporary directory per test function; tmp_path_factory can create multiple temporary directories shared across tests

💡 Hint

Think about scope and number of directories created.

tmp_path is a per-test temporary directory. tmp_path_factory can create multiple directories and can be shared across tests.

❓ framework

expert

Using tmp_path_factory for shared test resources

You want to create a temporary directory shared by multiple test functions in the same module using pytest fixtures. Which fixture setup correctly uses tmp_path_factory to achieve this?

PyTest

import pytest

@pytest.fixture(scope="module")
def shared_tmp_dir(tmp_path_factory):
    dir = tmp_path_factory.mktemp("shared")
    return dir

def test_one(shared_tmp_dir):
    file = shared_tmp_dir / "file1.txt"
    file.write_text("one")
    assert file.read_text() == "one"

def test_two(shared_tmp_dir):
    file = shared_tmp_dir / "file2.txt"
    file.write_text("two")
    assert file.read_text() == "two"

A The fixture shared_tmp_dir creates a module-scoped temp directory using tmp_path_factory.mktemp, shared by tests

B The fixture scope should be 'function' to share the directory

C The fixture should use tmp_path instead of tmp_path_factory for sharing directories

D tmp_path_factory cannot be used in fixtures

💡 Hint

Consider fixture scope and tmp_path_factory capabilities.

Using tmp_path_factory.mktemp inside a module-scoped fixture creates a shared temp directory for all tests in the module.