monkeypatch.setattr in PyTest - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to replace the function using monkeypatch.setattr.

PyTest

def test_func(monkeypatch):
    def fake_return():
        return 42
    monkeypatch.setattr('module.func', [1])
    assert module.func() == 42

Drag options to blanks, or click blank then click option'

Afunc

Bmodule.func

Creturn 42

Dfake_return

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the function name as a string instead of the function object.

Using the original function instead of the fake function.

We use monkeypatch.setattr to replace 'module.func' with the fake_return function.

2fill in blank

medium

Complete the code to patch the attribute 'value' of the object using monkeypatch.setattr.

PyTest

class MyClass:
    value = 10

def test_value(monkeypatch):
    obj = MyClass()
    monkeypatch.setattr(obj, 'value', [1])
    assert obj.value == 99

Drag options to blanks, or click blank then click option'

A99

B10

C'value'

Dobj.value

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the old value 10 instead of the new value.

Passing the attribute name instead of the new value.

We patch the attribute 'value' to be 99, so obj.value should equal 99.

3fill in blank

hard

Fix the error in the code to correctly patch the function using monkeypatch.setattr.

PyTest

def original():
    return 'original'

def fake():
    return 'fake'

def test_patch(monkeypatch):
    monkeypatch.setattr("original", [1])
    assert original() == 'fake'

Drag options to blanks, or click blank then click option'

A'fake'

Bfake

C'original'

Doriginal

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the function name as a string.

Passing the original function instead of the fake function.

monkeypatch.setattr expects the target and the new value (function) to replace it. We pass the function fake without quotes.

4fill in blank

hard

Fill both blanks to patch the method 'get_data' of the class 'DataClass' to return 'mocked'.

PyTest

class DataClass:
    def get_data(self):
        return 'real'

def test_data(monkeypatch):
    monkeypatch.setattr(DataClass, [1], [2])
    obj = DataClass()
    assert obj.get_data() == 'mocked'

Drag options to blanks, or click blank then click option'

A'get_data'

Blambda self: 'mocked'

C'getData'

Dlambda: 'mocked'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method name string.

Using lambda without self parameter.

We patch the method 'get_data' with a lambda that takes self and returns 'mocked'.

5fill in blank

hard

Fill all three blanks to patch the function 'calculate' in module 'calc' to return 100 during the test.

PyTest

import calc

def fake_calc():
    return 100

def test_calculate(monkeypatch):
    monkeypatch.setattr(calc, [1], [2])
    result = calc.calculate()
    assert result == [3]

Drag options to blanks, or click blank then click option'

A'calculate'

Bfake_calc

C100

D'calc'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing function name without quotes.

Passing the function name as string instead of function object.

Asserting wrong expected value.

We patch 'calculate' in calc module with fake_calc function and assert the result is 100.