conftest.py

from .test_list import TextsToBeInspect


def pytest_assertrepr_compare(op, left, right):
    def details(*args):
        details = []
        details.append('----')
        for i in args:
            details.append('%s: ' % i.context)
            details.extend(['    %s' % i for i in i.texts])
        return details

    def unmatched(left, right):
        unmatched = []
        unmatched.append('--- unmatched ---')
        for value in right.texts:
            if value.startswith('invalid.data.'):
                continue
            if left.texts[right.texts.index(value)] != value:
                unmatched.append('%s: %s: ' % (left.context, left.texts[right.texts.index(value)]))
                unmatched.append('%s: %s: ' % (right.context, value))
        return unmatched

    explanation = []
    if isinstance(left, TextsToBeInspect) and isinstance(right, TextsToBeInspect) and op == "==":
        explanation.append('Comparing TextsToBeInspect instances: ')
        explanation.extend(unmatched(left, right))
        explanation.extend(details(left, right))
    return explanation

my_module.py

import sys

def runtests(args=None):
    import pytest

    result = pytest.main(['-vv', 'test_list.py', 'test_time.py'])
    sys.exit(result)


runtests()

test_list.py

import os
import pprint


class TextsToBeInspect(object):
    def __init__(self, context, texts):
        self.context = context[:]
        self.texts = texts[:]

    def __eq__(self, other):
        if not isinstance(other, TextsToBeInspect):
            return 0
        unmatched_found = False
        for value in other.texts:
            if value.startswith('invalid.data.'):
                continue
            if self.texts[other.texts.index(value)] != value:
                unmatched_found = True
        if unmatched_found:
            return 0
        return 1

    def texts(self):
        return self.texts[:]

    def context(self):
        return self.context[:]

    def pretty_print(self):
        print("\ncontext => {}".format(self.context))
        pp.pprint(self.texts)


texts_expect = [
    "invalid.data.aaaaaaaaaaaaaaaaaaaaaaaaaaa",
    "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
    "cccccccccccccccccccccccccccccccccccccccc",
    "invalid.data.ddddddddddddddddddddddddddd",
]

texts_actual = [
    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
    "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
    "cccccccccccccccccccccccccccccccccccccccERROR",
    "dddddddddddddddddddddddddddddddddddddddd",
]

pp = pprint.PrettyPrinter(indent=4)
__tracebackhide__ = True


def test_list():
    actual = TextsToBeInspect("actual", texts_actual)
    expect = TextsToBeInspect("expect", texts_expect)
    assert actual == expect