tests: replace all "assert" by unittest assertions

If the assert fails because of a comparison, it is useful that the
test suite log contains a comparison of these values.
unittest.assertEqual() and friends do that for us.

* HACKING: Add a section about Python tests.
* tests/sanity/style.test: Forbid the use of "assert" in
Python tests.
* tests/python/298.py, tests/python/341.py, tests/python/471.py,
tests/python/accparse2.py, tests/python/aiger.py,
tests/python/aliases.py, tests/python/alternating.py,
tests/python/bdddict.py, tests/python/bdditer.py,
tests/python/bugdet.py, tests/python/complement_semidet.py,
tests/python/declenv.py, tests/python/decompose_scc.py,
tests/python/det.py, tests/python/dualize.py, tests/python/ecfalse.py,
tests/python/except.py, tests/python/game.py, tests/python/gen.py,
tests/python/genem.py, tests/python/implies.py,
tests/python/intrun.py, tests/python/kripke.py,
tests/python/langmap.py, tests/python/ltl2tgba.py,
tests/python/ltlf.py, tests/python/ltlparse.py,
tests/python/ltlsimple.py, tests/python/mealy.py,
tests/python/merge.py, tests/python/mergedge.py,
tests/python/misc-ec.py, tests/python/optionmap.py,
tests/python/origstate.py, tests/python/otfcrash.py,
tests/python/parity.py, tests/python/parsetgba.py,
tests/python/pdegen.py, tests/python/prodexpt.py,
tests/python/randgen.py, tests/python/relabel.py,
tests/python/remfin.py, tests/python/removeap.py,
tests/python/rs_like.py, tests/python/satmin.py,
tests/python/sbacc.py, tests/python/sccfilter.py,
tests/python/sccinfo.py, tests/python/sccsplit.py,
tests/python/semidet.py, tests/python/setacc.py,
tests/python/setxor.py, tests/python/simplacc.py,
tests/python/simstate.py, tests/python/sonf.py, tests/python/split.py,
tests/python/streett_totgba.py, tests/python/streett_totgba2.py,
tests/python/stutter.py, tests/python/sum.py,
tests/python/synthesis.py, tests/python/toparity.py,
tests/python/toweak.py, tests/python/tra2tba.py,
tests/python/trival.py, tests/python/twagraph.py,
tests/python/zlktree.py: Replace all occurrences of "assert" by calls
to unittest.TestCase methods.

tests/python/genem.py

@@ -1,6 +1,6 @@
 # -*- mode: python; coding: utf-8 -*-
-# Copyright (C) 2018-2022 Laboratoire de Recherche et Développement de l'Epita
-# (LRDE).
+# Copyright (C) 2018-2022 Laboratoire de Recherche et Développement de
+# l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
 #
@@ -22,6 +22,8 @@
 # are usable with methods from the spot package.
 
 import spot
+from unittest import TestCase
+tc = TestCase()
 
 a1 = spot.automaton('''
 HOA: v1  name: "aut"  States: 4  Start: 0  AP: 0
@@ -179,7 +181,7 @@ def generic_emptiness2_rec(aut):
                 # Find some Fin set, we necessarily have one, otherwise the SCC
                 # would have been found to be either rejecting or accepting.
                 fo = acc.fin_one()
-                assert fo >= 0, acc
+                tc.assertTrue(fo >= 0, acc)
                 for part in si.split_on_sets(scc, [fo]):
                     if not generic_emptiness2(part):
                         return False
@@ -309,10 +311,10 @@ def run_bench(automata):
                + str(res3b)[0] + str(res3c)[0] + str(res3d)[0]
                + str(res4)[0] + str(res5)[0])
         print(res)
-        assert res in ('TTTTTTTT', 'FFFFFFFF')
+        tc.assertIn(res, ('TTTTTTTT', 'FFFFFFFF'))
         if res == 'FFFFFFFF':
             run3 = spot.generic_accepting_run(aut)
-            assert run3.replay(spot.get_cout()) is True
+            tc.assertTrue(run3.replay(spot.get_cout()))
 
 
 run_bench([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a360, act])