Dynamically Generating Parameterized unittest Test Cases with setattr

In automated testing, many case scenarios require different parameter combinations, and developers often need distinct test cases that clearly indicate which parameters are being tested rather than a single large test case.

The problem is to create individual test cases for each combination of input parameters (e.g., 10 data sets should produce 10 test cases) without manually writing numerous test_ methods.

One possible approach is to avoid relying on the default unittest.TestCase test_ methods and instead generate test functions dynamically. By using setattr together with a static method that returns a test function, the framework can automatically add new test methods to a TestCase subclass.

The implementation steps are:

Define a TestCase subclass with a generic test method that accepts parameters.

Create a static method that, given specific parameters, returns a function calling the generic test method.

Iterate over the desired parameter tuples and use setattr to attach a new test method to the class.

Invoke the generation function before the test runner starts.

Example code:

import unittest

class Test_demo(unittest.TestCase):
    def test01_case(self, times=1, num=1):
        """Description=测试用例"""
        if times == 1 or num == 1:
            rl = requests.get(url=url, params=data).json()
        else:
            for i in range(0, 2):
                rl = requests.get(url=url, params=data).json()

    @staticmethod
    def getTestfun(times, num):
        def func(self):
            self.test01_case(times, num)
        return func

def generate_cases():
    data = [(1, 2), (2, 3)]
    for args in data:
        setattr(Test_demo, "test_func_%s_%s" % (args, num), Test_demo.getTestfun(*args))

generate_cases()

if __name__ == '__main__':
    unittest.main()

This technique allows each parameter set to be represented by its own test case, making test results easier to interpret and reducing the need for manual test method creation.