run pyupgrade

34 files changed, 102 insertions, 102 deletions

diff --git a/_pytest/_code/code.py b/_pytest/_code/code.py
index 76e143774..46abb15bb 100644
--- a/_pytest/_code/code.py
+++ b/_pytest/_code/code.py
@@ -455,7 +455,7 @@ class ExceptionInfo(object):
         """
         __tracebackhide__ = True
         if not re.search(regexp, str(self.value)):
-            assert 0, "Pattern '{0!s}' not found in '{1!s}'".format(
+            assert 0, "Pattern '{!s}' not found in '{!s}'".format(
                 regexp, self.value)
         return True
 
diff --git a/_pytest/assertion/rewrite.py b/_pytest/assertion/rewrite.py
index 0499a792f..ff1261788 100644
--- a/_pytest/assertion/rewrite.py
+++ b/_pytest/assertion/rewrite.py
@@ -904,7 +904,7 @@ class AssertionRewriter(ast.NodeVisitor):
         self.push_format_context()
         left_res, left_expl = self.visit(comp.left)
         if isinstance(comp.left, (ast.Compare, ast.BoolOp)):
-            left_expl = "({0})".format(left_expl)
+            left_expl = "({})".format(left_expl)
         res_variables = [self.variable() for i in range(len(comp.ops))]
         load_names = [ast.Name(v, ast.Load()) for v in res_variables]
         store_names = [ast.Name(v, ast.Store()) for v in res_variables]
@@ -915,7 +915,7 @@ class AssertionRewriter(ast.NodeVisitor):
         for i, op, next_operand in it:
             next_res, next_expl = self.visit(next_operand)
             if isinstance(next_operand, (ast.Compare, ast.BoolOp)):
-                next_expl = "({0})".format(next_expl)
+                next_expl = "({})".format(next_expl)
             results.append(next_res)
             sym = binop_map[op.__class__]
             syms.append(ast.Str(sym))
diff --git a/_pytest/assertion/truncate.py b/_pytest/assertion/truncate.py
index 2ed12e2e5..912a2f16f 100644
--- a/_pytest/assertion/truncate.py
+++ b/_pytest/assertion/truncate.py
@@ -69,10 +69,10 @@ def _truncate_explanation(input_lines, max_lines=None, max_chars=None):
     truncated_line_count += 1  # Account for the part-truncated final line
     msg = '...Full output truncated'
     if truncated_line_count == 1:
-        msg += ' ({0} line hidden)'.format(truncated_line_count)
+        msg += ' ({} line hidden)'.format(truncated_line_count)
     else:
-        msg += ' ({0} lines hidden)'.format(truncated_line_count)
-    msg += ", {0}" .format(USAGE_MSG)
+        msg += ' ({} lines hidden)'.format(truncated_line_count)
+    msg += ", {}" .format(USAGE_MSG)
     truncated_explanation.extend([
         six.text_type(""),
         six.text_type(msg),
diff --git a/_pytest/assertion/util.py b/_pytest/assertion/util.py
index 7848d0997..88d1ebc69 100644
--- a/_pytest/assertion/util.py
+++ b/_pytest/assertion/util.py
@@ -275,14 +275,14 @@ def _compare_eq_set(left, right, verbose=False):
 def _compare_eq_dict(left, right, verbose=False):
     explanation = []
     common = set(left).intersection(set(right))
-    same = dict((k, left[k]) for k in common if left[k] == right[k])
+    same = {k: left[k] for k in common if left[k] == right[k]}
     if same and verbose < 2:
         explanation += [u('Omitting %s identical items, use -vv to show') %
                         len(same)]
     elif same:
         explanation += [u('Common items:')]
         explanation += pprint.pformat(same).splitlines()
-    diff = set(k for k in common if left[k] != right[k])
+    diff = {k for k in common if left[k] != right[k]}
     if diff:
         explanation += [u('Differing items:')]
         for k in diff:
@@ -292,12 +292,12 @@ def _compare_eq_dict(left, right, verbose=False):
     if extra_left:
         explanation.append(u('Left contains more items:'))
         explanation.extend(pprint.pformat(
-            dict((k, left[k]) for k in extra_left)).splitlines())
+            {k: left[k] for k in extra_left}).splitlines())
     extra_right = set(right) - set(left)
     if extra_right:
         explanation.append(u('Right contains more items:'))
         explanation.extend(pprint.pformat(
-            dict((k, right[k]) for k in extra_right)).splitlines())
+            {k: right[k] for k in extra_right}).splitlines())
     return explanation
 
 
diff --git a/_pytest/capture.py b/_pytest/capture.py
index d71f59ac2..99ba817a0 100644
--- a/_pytest/capture.py
+++ b/_pytest/capture.py
@@ -184,12 +184,12 @@ capture_fixtures = {'capfd', 'capfdbinary', 'capsys', 'capsysbinary'}
 
 
 def _ensure_only_one_capture_fixture(request, name):
-    fixtures = set(request.fixturenames) & capture_fixtures - set((name,))
+    fixtures = set(request.fixturenames) & capture_fixtures - {name}
     if fixtures:
         fixtures = sorted(fixtures)
         fixtures = fixtures[0] if len(fixtures) == 1 else fixtures
         raise request.raiseerror(
-            "cannot use {0} and {1} at the same time".format(
+            "cannot use {} and {} at the same time".format(
                 fixtures, name,
             ),
         )
diff --git a/_pytest/config.py b/_pytest/config.py
index 86632ed64..426e9627c 100644
--- a/_pytest/config.py
+++ b/_pytest/config.py
@@ -89,7 +89,7 @@ def filename_arg(path, optname):
     :optname: name of the option
     """
     if os.path.isdir(path):
-        raise UsageError("{0} must be a filename, given: {1}".format(optname, path))
+        raise UsageError("{} must be a filename, given: {}".format(optname, path))
     return path
 
 
@@ -100,7 +100,7 @@ def directory_arg(path, optname):
     :optname: name of the option
     """
     if not os.path.isdir(path):
-        raise UsageError("{0} must be a directory, given: {1}".format(optname, path))
+        raise UsageError("{} must be a directory, given: {}".format(optname, path))
     return path
 
 
@@ -253,7 +253,7 @@ class PytestPluginManager(PluginManager):
 
     def register(self, plugin, name=None):
         if name in ['pytest_catchlog', 'pytest_capturelog']:
-            self._warn('{0} plugin has been merged into the core, '
+            self._warn('{} plugin has been merged into the core, '
                        'please remove it from your requirements.'.format(
                            name.replace('_', '-')))
             return
@@ -735,7 +735,7 @@ class Argument(object):
             args += ['type: ' + repr(self.type)]
         if hasattr(self, 'default'):
             args += ['default: ' + repr(self.default)]
-        return 'Argument({0})'.format(', '.join(args))
+        return 'Argument({})'.format(', '.join(args))
 
 
 class OptionGroup(object):
diff --git a/_pytest/fixtures.py b/_pytest/fixtures.py
index 7b109ec11..5bbe94db8 100644
--- a/_pytest/fixtures.py
+++ b/_pytest/fixtures.py
@@ -493,8 +493,8 @@ class FixtureRequest(FuncargnamesCompatAttr):
                     source_path = source_path.relto(funcitem.config.rootdir)
                 msg = (
                     "The requested fixture has no parameter defined for the "
-                    "current test.\n\nRequested fixture '{0}' defined in:\n{1}"
-                    "\n\nRequested here:\n{2}:{3}".format(
+                    "current test.\n\nRequested fixture '{}' defined in:\n{}"
+                    "\n\nRequested here:\n{}:{}".format(
                         fixturedef.argname,
                         getlocation(fixturedef.func, funcitem.config.rootdir),
                         source_path,
@@ -612,8 +612,8 @@ def scope2index(scope, descr, where=None):
         return scopes.index(scope)
     except ValueError:
         raise ValueError(
-            "{0} {1}has an unsupported scope value '{2}'".format(
-                descr, 'from {0} '.format(where) if where else '',
+            "{} {}has an unsupported scope value '{}'".format(
+                descr, 'from {} '.format(where) if where else '',
                 scope)
         )
 
@@ -681,10 +681,10 @@ class FixtureLookupErrorRepr(TerminalRepr):
             tw.line(tbline.rstrip())
         lines = self.errorstring.split("\n")
         if lines:
-            tw.line('{0}       {1}'.format(FormattedExcinfo.fail_marker,
+            tw.line('{}       {}'.format(FormattedExcinfo.fail_marker,
                                            lines[0].strip()), red=True)
             for line in lines[1:]:
-                tw.line('{0}       {1}'.format(FormattedExcinfo.flow_marker,
+                tw.line('{}       {}'.format(FormattedExcinfo.flow_marker,
                                                line.strip()), red=True)
         tw.line()
         tw.line("%s:%d" % (self.filename, self.firstlineno + 1))
@@ -732,7 +732,7 @@ class FixtureDef(object):
         self.scope = scope
         self.scopenum = scope2index(
             scope or "function",
-            descr='fixture {0}'.format(func.__name__),
+            descr='fixture {}'.format(func.__name__),
             where=baseid
         )
         self.params = params
diff --git a/_pytest/logging.py b/_pytest/logging.py
index 66ed6900b..fc511f767 100644
--- a/_pytest/logging.py
+++ b/_pytest/logging.py
@@ -318,8 +318,8 @@ def get_actual_log_level(config, *setting_names):
     except ValueError:
         # Python logging does not recognise this as a logging level
         raise pytest.UsageError(
-            "'{0}' is not recognized as a logging level name for "
-            "'{1}'. Please consider passing the "
+            "'{}' is not recognized as a logging level name for "
+            "'{}'. Please consider passing the "
             "logging level num instead.".format(
                 log_level,
                 setting_name))
diff --git a/_pytest/main.py b/_pytest/main.py
index 6c4bd65bb..b3027fc25 100644
--- a/_pytest/main.py
+++ b/_pytest/main.py
@@ -112,7 +112,7 @@ def wrap_session(config, doit):
         except KeyboardInterrupt:
             excinfo = _pytest._code.ExceptionInfo()
             if initstate < 2 and isinstance(excinfo.value, exit.Exception):
-                sys.stderr.write('{0}: {1}\n'.format(
+                sys.stderr.write('{}: {}\n'.format(
                     excinfo.typename, excinfo.value.msg))
             config.hook.pytest_keyboard_interrupt(excinfo=excinfo)
             session.exitstatus = EXIT_INTERRUPTED
diff --git a/_pytest/mark/legacy.py b/_pytest/mark/legacy.py
index 5c7b8d001..30c7239bf 100644
--- a/_pytest/mark/legacy.py
+++ b/_pytest/mark/legacy.py
@@ -17,7 +17,7 @@ class MarkMapping(object):
 
     @classmethod
     def from_item(cls, item):
-        mark_names = set(mark.name for mark in item.iter_markers())
+        mark_names = {mark.name for mark in item.iter_markers()}
         return cls(mark_names)
 
     def __getitem__(self, name):
diff --git a/_pytest/mark/structures.py b/_pytest/mark/structures.py
index 72fd264b2..8ec6bbce9 100644
--- a/_pytest/mark/structures.py
+++ b/_pytest/mark/structures.py
@@ -296,7 +296,7 @@ class MarkInfo(object):
         return cls([mark])
 
     def __repr__(self):
-        return "<MarkInfo {0!r}>".format(self.combined)
+        return "<MarkInfo {!r}>".format(self.combined)
 
     def add_mark(self, mark):
         """ add a MarkInfo with the given args and kwargs. """
diff --git a/_pytest/outcomes.py b/_pytest/outcomes.py
index 640c5773a..7ced846ea 100644
--- a/_pytest/outcomes.py
+++ b/_pytest/outcomes.py
@@ -75,7 +75,7 @@ def skip(msg="", **kwargs):
     allow_module_level = kwargs.pop('allow_module_level', False)
     if kwargs:
         keys = [k for k in kwargs.keys()]
-        raise TypeError('unexpected keyword arguments: {0}'.format(keys))
+        raise TypeError('unexpected keyword arguments: {}'.format(keys))
     raise Skipped(msg=msg, allow_module_level=allow_module_level)
 
 
diff --git a/_pytest/pytester.py b/_pytest/pytester.py
index 27dd8289d..f2e972075 100644
--- a/_pytest/pytester.py
+++ b/_pytest/pytester.py
@@ -97,7 +97,7 @@ class LsofFdLeakChecker(object):
             gc.collect()
         lines2 = self.get_open_files()
 
-        new_fds = set([t[0] for t in lines2]) - set([t[0] for t in lines1])
+        new_fds = {t[0] for t in lines2} - {t[0] for t in lines1}
         leaked_files = [t for t in lines2 if t[0] in new_fds]
         if leaked_files:
             error = []
diff --git a/_pytest/python.py b/_pytest/python.py
index 8bcb051a2..1e8e0cd1b 100644
--- a/_pytest/python.py
+++ b/_pytest/python.py
@@ -813,7 +813,7 @@ class Metafunc(fixtures.FuncargnamesCompatAttr):
         if scope is None:
             scope = _find_parametrized_scope(argnames, self._arg2fixturedefs, indirect)
 
-        scopenum = scope2index(scope, descr='call to {0}'.format(self.parametrize))
+        scopenum = scope2index(scope, descr='call to {}'.format(self.parametrize))
         valtypes = {}
         for arg in argnames:
             if arg not in self.fixturenames:
@@ -858,8 +858,8 @@ class Metafunc(fixtures.FuncargnamesCompatAttr):
             for a_id, param, param_index in elements:
                 if len(param.values) != len(argnames):
                     raise ValueError(
-                        'In "parametrize" the number of values ({0}) must be '
-                        'equal to the number of names ({1})'.format(
+                        'In "parametrize" the number of values ({}) must be '
+                        'equal to the number of names ({})'.format(
                             param.values, argnames))
                 newcallspec = callspec.copy(self)
                 newcallspec.setmulti2(valtypes, argnames, param.values, a_id,
@@ -1016,7 +1016,7 @@ def _show_fixtures_per_test(config, session):
             return
         if verbose > 0:
             bestrel = get_best_relpath(fixture_def.func)
-            funcargspec = "{0} -- {1}".format(argname, bestrel)
+            funcargspec = "{} -- {}".format(argname, bestrel)
         else:
             funcargspec = argname
         tw.line(funcargspec, green=True)
@@ -1036,8 +1036,8 @@ def _show_fixtures_per_test(config, session):
             # this test item does not use any fixtures
             return
         tw.line()
-        tw.sep('-', 'fixtures used by {0}'.format(item.name))
-        tw.sep('-', '({0})'.format(get_best_relpath(item.function)))
+        tw.sep('-', 'fixtures used by {}'.format(item.name))
+        tw.sep('-', '({})'.format(get_best_relpath(item.function)))
         # dict key not used in loop but needed for sorting
         for _, fixturedefs in sorted(info.name2fixturedefs.items()):
             assert fixturedefs is not None
diff --git a/_pytest/python_api.py b/_pytest/python_api.py
index 838a4a50c..de3c9a1fe 100644
--- a/_pytest/python_api.py
+++ b/_pytest/python_api.py
@@ -79,7 +79,7 @@ class ApproxNumpy(ApproxBase):
         # shape of the array...
         import numpy as np
 
-        return "approx({0!r})".format(list(
+        return "approx({!r})".format(list(
             self._approx_scalar(x) for x in np.asarray(self.expected)))
 
     if sys.version_info[0] == 2:
@@ -94,7 +94,7 @@ class ApproxNumpy(ApproxBase):
             try:
                 actual = np.asarray(actual)
             except:  # noqa
-                raise TypeError("cannot compare '{0}' to numpy.ndarray".format(actual))
+                raise TypeError("cannot compare '{}' to numpy.ndarray".format(actual))
 
         if not np.isscalar(actual) and actual.shape != self.expected.shape:
             return False
@@ -123,9 +123,9 @@ class ApproxMapping(ApproxBase):
     """
 
     def __repr__(self):
-        return "approx({0!r})".format(dict(
-            (k, self._approx_scalar(v))
-            for k, v in self.expected.items()))
+        return "approx({!r})".format({
+            k: self._approx_scalar(v)
+            for k, v in self.expected.items()})
 
     def __eq__(self, actual):
         if set(actual.keys()) != set(self.expected.keys()):
@@ -147,7 +147,7 @@ class ApproxSequence(ApproxBase):
         seq_type = type(self.expected)
         if seq_type not in (tuple, list, set):
             seq_type = list
-        return "approx({0!r})".format(seq_type(
+        return "approx({!r})".format(seq_type(
             self._approx_scalar(x) for x in self.expected))
 
     def __eq__(self, actual):
@@ -189,9 +189,9 @@ class ApproxScalar(ApproxBase):
             vetted_tolerance = '???'
 
         if sys.version_info[0] == 2:
-            return '{0} +- {1}'.format(self.expected, vetted_tolerance)
+            return '{} +- {}'.format(self.expected, vetted_tolerance)
         else:
-            return u'{0} \u00b1 {1}'.format(self.expected, vetted_tolerance)
+            return u'{} \u00b1 {}'.format(self.expected, vetted_tolerance)
 
     def __eq__(self, actual):
         """
@@ -591,7 +591,7 @@ def raises(expected_exception, *args, **kwargs):
                " derived from BaseException, not %s")
         raise TypeError(msg % type(exc))
 
-    message = "DID NOT RAISE {0}".format(expected_exception)
+    message = "DID NOT RAISE {}".format(expected_exception)
     match_expr = None
 
     if not args:
diff --git a/_pytest/recwarn.py b/_pytest/recwarn.py
index ab0f79c75..7f9fcb30a 100644
--- a/_pytest/recwarn.py
+++ b/_pytest/recwarn.py
@@ -217,8 +217,8 @@ class WarningsChecker(WarningsRecorder):
                 if not any(issubclass(r.category, self.expected_warning)
                            for r in self):
                     __tracebackhide__ = True
-                    fail("DID NOT WARN. No warnings of type {0} was emitted. "
-                         "The list of emitted warnings is: {1}.".format(
+                    fail("DID NOT WARN. No warnings of type {} was emitted. "
+                         "The list of emitted warnings is: {}.".format(
                              self.expected_warning,
                              [each.message for each in self]))
                 elif self.match_expr is not None:
@@ -227,7 +227,7 @@ class WarningsChecker(WarningsRecorder):
                             if re.compile(self.match_expr).search(str(r.message)):
                                 break
                     else:
-                        fail("DID NOT WARN. No warnings of type {0} matching"
-                             " ('{1}') was emitted. The list of emitted warnings"
-                             " is: {2}.".format(self.expected_warning, self.match_expr,
+                        fail("DID NOT WARN. No warnings of type {} matching"
+                             " ('{}') was emitted. The list of emitted warnings"
+                             " is: {}.".format(self.expected_warning, self.match_expr,
                                                 [each.message for each in self]))
diff --git a/_pytest/runner.py b/_pytest/runner.py
index 6df558a7f..3951f29d5 100644
--- a/_pytest/runner.py
+++ b/_pytest/runner.py
@@ -95,7 +95,7 @@ def show_test_item(item):
     tw.write(item._nodeid)
     used_fixtures = sorted(item._fixtureinfo.name2fixturedefs.keys())
     if used_fixtures:
-        tw.write(' (fixtures used: {0})'.format(', '.join(used_fixtures)))
+        tw.write(' (fixtures used: {})'.format(', '.join(used_fixtures)))
 
 
 def pytest_runtest_setup(item):
@@ -133,7 +133,7 @@ def _update_current_test_var(item, when):
     """
     var_name = 'PYTEST_CURRENT_TEST'
     if when:
-        value = '{0} ({1})'.format(item.nodeid, when)
+        value = '{} ({})'.format(item.nodeid, when)
         # don't allow null bytes on environment variables (see #2644, #2957)
         value = value.replace('\x00', '(null)')
         os.environ[var_name] = value
@@ -297,7 +297,7 @@ class BaseReport(object):
 def pytest_runtest_makereport(item, call):
     when = call.when
     duration = call.stop - call.start
-    keywords = dict([(x, 1) for x in item.keywords])
+    keywords = {x: 1 for x in item.keywords}
     excinfo = call.excinfo
     sections = []
     if not call.excinfo:
diff --git a/_pytest/setuponly.py b/_pytest/setuponly.py
index a1c7457d7..1af8fffb5 100644
--- a/_pytest/setuponly.py
+++ b/_pytest/setuponly.py
@@ -57,10 +57,10 @@ def _show_fixture_action(fixturedef, msg):
     if msg == 'SETUP':
         deps = sorted(arg for arg in fixturedef.argnames if arg != 'request')
         if deps:
-            tw.write(' (fixtures used: {0})'.format(', '.join(deps)))
+            tw.write(' (fixtures used: {})'.format(', '.join(deps)))
 
     if hasattr(fixturedef, 'cached_param'):
-        tw.write('[{0}]'.format(fixturedef.cached_param))
+        tw.write('[{}]'.format(fixturedef.cached_param))
 
     if capman:
         capman.resume_global_capture()
diff --git a/_pytest/skipping.py b/_pytest/skipping.py
index 36eb4a337..4c5a35364 100644
--- a/_pytest/skipping.py
+++ b/_pytest/skipping.py
@@ -116,7 +116,7 @@ def pytest_runtest_makereport(item, call):
     if hasattr(item, '_unexpectedsuccess') and rep.when == "call":
         from _pytest.compat import _is_unittest_unexpected_success_a_failure
         if item._unexpectedsuccess:
-            rep.longrepr = "Unexpected success: {0}".format(item._unexpectedsuccess)
+            rep.longrepr = "Unexpected success: {}".format(item._unexpectedsuccess)
         else:
             rep.longrepr = "Unexpected success"
         if _is_unittest_unexpected_success_a_failure():
@@ -143,7 +143,7 @@ def pytest_runtest_makereport(item, call):
             explanation = evalxfail.getexplanation()
             if is_strict_xfail:
                 rep.outcome = "failed"
-                rep.longrepr = "[XPASS(strict)] {0}".format(explanation)
+                rep.longrepr = "[XPASS(strict)] {}".format(explanation)
             else:
                 rep.outcome = "passed"
                 rep.wasxfail = explanation
diff --git a/doc/en/example/assertion/failure_demo.py b/doc/en/example/assertion/failure_demo.py
index 3ae0268d3..ee4dbdba7 100644
--- a/doc/en/example/assertion/failure_demo.py
+++ b/doc/en/example/assertion/failure_demo.py
@@ -70,7 +70,7 @@ class TestSpecialisedExplanations(object):
         assert {'a': 0, 'b': 1, 'c': 0} == {'a': 0, 'b': 2, 'd': 0}
 
     def test_eq_set(self):
-        assert set([0, 10, 11, 12]) == set([0, 20, 21])
+        assert {0, 10, 11, 12} == {0, 20, 21}
 
     def test_eq_longer_list(self):
         assert [1,2] == [1,2,3]
diff --git a/testing/acceptance_test.py b/testing/acceptance_test.py
index 8ceb3bae1..711e5a86c 100644
--- a/testing/acceptance_test.py
+++ b/testing/acceptance_test.py
@@ -599,8 +599,8 @@ class TestInvocationVariants(object):
                 "__import__('pkg_resources').declare_namespace(__name__)")
             lib = ns.mkdir(dirname)
             lib.ensure("__init__.py")
-            lib.join("test_{0}.py".format(dirname)). \
-                write("def test_{0}(): pass\n"
+            lib.join("test_{}.py".format(dirname)). \
+                write("def test_{}(): pass\n"
                       "def test_other():pass".format(dirname))
 
         # The structure of the test directory is now:
diff --git a/testing/code/test_excinfo.py b/testing/code/test_excinfo.py
index 8fd59423f..0f044c9f5 100644
--- a/testing/code/test_excinfo.py
+++ b/testing/code/test_excinfo.py
@@ -203,8 +203,8 @@ class TestTraceback_f_g_h(object):
         excinfo = pytest.raises(ValueError, h)
         traceback = excinfo.traceback
         ntraceback = traceback.filter()
-        print('old: {0!r}'.format(traceback))
-        print('new: {0!r}'.format(ntraceback))
+        print('old: {!r}'.format(traceback))
+        print('new: {!r}'.format(ntraceback))
 
         if matching:
             assert len(ntraceback) == len(traceback) - 2
diff --git a/testing/deprecated_test.py b/testing/deprecated_test.py
index cb66472c9..2f354e817 100644
--- a/testing/deprecated_test.py
+++ b/testing/deprecated_test.py
@@ -126,7 +126,7 @@ def test_terminal_reporter_writer_attr(pytestconfig):
 def test_pytest_catchlog_deprecated(testdir, plugin):
     testdir.makepyfile("""
         def test_func(pytestconfig):
-            pytestconfig.pluginmanager.register(None, 'pytest_{0}')
+            pytestconfig.pluginmanager.register(None, 'pytest_{}')
     """.format(plugin))
     res = testdir.runpytest()
     assert res.ret == 0
diff --git a/testing/logging/test_reporting.py b/testing/logging/test_reporting.py
index 699df0e60..6e3f9c07b 100644
--- a/testing/logging/test_reporting.py
+++ b/testing/logging/test_reporting.py
@@ -596,7 +596,7 @@ def test_log_file_cli(testdir):
 
     log_file = testdir.tmpdir.join('pytest.log').strpath
 
-    result = testdir.runpytest('-s', '--log-file={0}'.format(log_file), '--log-file-level=WARNING')
+    result = testdir.runpytest('-s', '--log-file={}'.format(log_file), '--log-file-level=WARNING')
 
     # fnmatch_lines does an assertion internally
     result.stdout.fnmatch_lines([
@@ -628,7 +628,7 @@ def test_log_file_cli_level(testdir):
     log_file = testdir.tmpdir.join('pytest.log').strpath
 
     result = testdir.runpytest('-s',
-                               '--log-file={0}'.format(log_file),
+                               '--log-file={}'.format(log_file),
                                '--log-file-level=INFO')
 
     # fnmatch_lines does an assertion internally
@@ -661,7 +661,7 @@ def test_log_file_ini(testdir):
     testdir.makeini(
         """
         [pytest]
-        log_file={0}
+        log_file={}
         log_file_level=WARNING
         """.format(log_file))
     testdir.makepyfile('''
@@ -697,7 +697,7 @@ def test_log_file_ini_level(testdir):
     testdir.makeini(
         """
         [pytest]
-        log_file={0}
+        log_file={}
         log_file_level = INFO
         """.format(log_file))
     testdir.makepyfile('''
diff --git a/testing/python/approx.py b/testing/python/approx.py
index 9ca21bdf8..6ebe2e512 100644
--- a/testing/python/approx.py
+++ b/testing/python/approx.py
@@ -375,7 +375,7 @@ class TestApprox(object):
         expected = '4.0e-06'
         result = testdir.runpytest()
         result.stdout.fnmatch_lines([
-            '*At index 0 diff: 3 != 4 * {0}'.format(expected),
+            '*At index 0 diff: 3 != 4 * {}'.format(expected),
             '=* 1 failed in *=',
         ])
 
diff --git a/testing/python/fixture.py b/testing/python/fixture.py
index d9f08a3f0..d8af217cf 100644
--- a/testing/python/fixture.py
+++ b/testing/python/fixture.py
@@ -1749,7 +1749,7 @@ class TestAutouseManagement(object):
                 def test_2(self):
                     pass
         """)
-        confcut = "--confcutdir={0}".format(testdir.tmpdir)
+        confcut = "--confcutdir={}".format(testdir.tmpdir)
         reprec = testdir.inline_run("-v", "-s", confcut)
         reprec.assertoutcome(passed=8)
         config = reprec.getcalls("pytest_unconfigure")[0].config
@@ -3132,9 +3132,9 @@ class TestParameterizedSubRequest(object):
             E*Failed: The requested fixture has no parameter defined for the current test.
             E*
             E*Requested fixture 'fix_with_param' defined in:
-            E*{0}:4
+            E*{}:4
             E*Requested here:
-            E*{1}:9
+            E*{}:9
             *1 error*
             """.format(testfile.basename, testfile.basename))
 
@@ -3154,9 +3154,9 @@ class TestParameterizedSubRequest(object):
             E*Failed: The requested fixture has no parameter defined for the current test.
             E*
             E*Requested fixture 'fix_with_param' defined in:
-            E*{0}:4
+            E*{}:4
             E*Requested here:
-            E*{1}:8
+            E*{}:8
             *1 failed*
             """.format(testfile.basename, testfile.basename))
 
@@ -3178,9 +3178,9 @@ class TestParameterizedSubRequest(object):
             E*Failed: The requested fixture has no parameter defined for the current test.
             E*
             E*Requested fixture 'fix_with_param' defined in:
-            E*{0}:4
+            E*{}:4
             E*Requested here:
-            E*{1}:2
+            E*{}:2
             *1 failed*
             """.format(conffile.basename, testfile.basename))
 
@@ -3211,9 +3211,9 @@ class TestParameterizedSubRequest(object):
             E*Failed: The requested fixture has no parameter defined for the current test.
             E*
             E*Requested fixture 'fix_with_param' defined in:
-            E*{0}:5
+            E*{}:5
             E*Requested here:
-            E*{1}:5
+            E*{}:5
             *1 failed*
             """.format(fixfile.strpath, testfile.basename))
 
diff --git a/testing/python/metafunc.py b/testing/python/metafunc.py
index db6dae318..1942005bb 100644
--- a/testing/python/metafunc.py
+++ b/testing/python/metafunc.py
@@ -306,7 +306,7 @@ class TestMetafunc(object):
             pytest.param(re.compile('foo'), re.compile('bar')),
             pytest.param(str, int),
             pytest.param(list("six"), [66, 66]),
-            pytest.param(set([7]), set("seven")),
+            pytest.param({7}, set("seven")),
             pytest.param(tuple("eight"), (8, -8, 8)),
             pytest.param(b'\xc3\xb4', b"name"),
             pytest.param(b'\xc3\xb4', totext("other")),
@@ -1214,14 +1214,14 @@ class TestMetafuncFunctional(object):
         testdir.makepyfile("""
             import pytest
 
-            @pytest.mark.{0}("x", range(2))
+            @pytest.mark.{}("x", range(2))
             def test_foo(x):
                 pass
         """.format(attr))
         reprec = testdir.inline_run('--collectonly')
         failures = reprec.getfailures()
         assert len(failures) == 1
-        expectederror = "MarkerError: test_foo has '{0}', spelling should be 'parametrize'".format(attr)
+        expectederror = "MarkerError: test_foo has '{}', spelling should be 'parametrize'".format(attr)
         assert expectederror in failures[0].longrepr.reprcrash.message
 
 
diff --git a/testing/python/raises.py b/testing/python/raises.py
index 053426395..3904d9757 100644
--- a/testing/python/raises.py
+++ b/testing/python/raises.py
@@ -75,7 +75,7 @@ class TestRaises(object):
         try:
             pytest.raises(ValueError, int, '0')
         except pytest.raises.Exception as e:
-            assert e.msg == "DID NOT RAISE {0}".format(repr(ValueError))
+            assert e.msg == "DID NOT RAISE {}".format(repr(ValueError))
         else:
             assert False, "Expected pytest.raises.Exception"
 
@@ -83,7 +83,7 @@ class TestRaises(object):
             with pytest.raises(ValueError):
                 pass
         except pytest.raises.Exception as e:
-            assert e.msg == "DID NOT RAISE {0}".format(repr(ValueError))
+            assert e.msg == "DID NOT RAISE {}".format(repr(ValueError))
         else:
             assert False, "Expected pytest.raises.Exception"
 
@@ -134,7 +134,7 @@ class TestRaises(object):
             int('asdf')
 
         msg = "with base 16"
-        expr = r"Pattern '{0}' not found in 'invalid literal for int\(\) with base 10: 'asdf''".format(msg)
+        expr = r"Pattern '{}' not found in 'invalid literal for int\(\) with base 10: 'asdf''".format(msg)
         with pytest.raises(AssertionError, match=expr):
             with pytest.raises(ValueError, match=msg):
                 int('asdf', base=10)
diff --git a/testing/test_assertion.py b/testing/test_assertion.py
index 51229d3e1..f7b69ba2d 100644
--- a/testing/test_assertion.py
+++ b/testing/test_assertion.py
@@ -359,7 +359,7 @@ class TestAssert_reprcompare(object):
                 + {0: 2}
                 ?     ^
             """),
-            (set([0, 1]), set([0, 2]), """
+            ({0, 1}, {0, 2}, """
                 Full diff:
                 - set([0, 1])
                 ?         ^
@@ -417,11 +417,11 @@ class TestAssert_reprcompare(object):
         assert lines[2] == "{'b': 1}"
 
     def test_set(self):
-        expl = callequal(set([0, 1]), set([0, 2]))
+        expl = callequal({0, 1}, {0, 2})
         assert len(expl) > 1
 
     def test_frozenzet(self):
-        expl = callequal(frozenset([0, 1]), set([0, 2]))
+        expl = callequal(frozenset([0, 1]), {0, 2})
         assert len(expl) > 1
 
     def test_Sequence(self):
@@ -971,7 +971,7 @@ def test_set_with_unsortable_elements():
             raise RuntimeError()
 
         def __repr__(self):
-            return 'repr({0})'.format(self.name)
+            return 'repr({})'.format(self.name)
 
         def __eq__(self, other):
             return self.name == other.name
@@ -979,8 +979,8 @@ def test_set_with_unsortable_elements():
         def __hash__(self):
             return hash(self.name)
 
-    left_set = set(UnsortableKey(str(i)) for i in range(1, 3))
-    right_set = set(UnsortableKey(str(i)) for i in range(2, 4))
+    left_set = {UnsortableKey(str(i)) for i in range(1, 3)}
+    right_set = {UnsortableKey(str(i)) for i in range(2, 4)}
     expl = callequal(left_set, right_set, verbose=True)
     # skip first line because it contains the "construction" of the set, which does not have a guaranteed order
     expl = expl[1:]
diff --git a/testing/test_config.py b/testing/test_config.py
index 39105f5d6..c7b6647b7 100644
--- a/testing/test_config.py
+++ b/testing/test_config.py
@@ -624,7 +624,7 @@ def test_load_initial_conftest_last_ordering(testdir):
 def test_get_plugin_specs_as_list():
     from _pytest.config import _get_plugin_specs_as_list
     with pytest.raises(pytest.UsageError):
-        _get_plugin_specs_as_list(set(['foo']))
+        _get_plugin_specs_as_list({'foo'})
     with pytest.raises(pytest.UsageError):
         _get_plugin_specs_as_list(dict())
 
diff --git a/testing/test_doctest.py b/testing/test_doctest.py
index 314398395..b830473a4 100644
--- a/testing/test_doctest.py
+++ b/testing/test_doctest.py
@@ -117,8 +117,8 @@ class TestDoctests(object):
             >>> 1
             1
         """)
-        expected = set(['xdoc.txt', 'test.foo', 'test_normal.txt'])
-        assert set(x.basename for x in testdir.tmpdir.listdir()) == expected
+        expected = {'xdoc.txt', 'test.foo', 'test_normal.txt'}
+        assert {x.basename for x in testdir.tmpdir.listdir()} == expected
         args = ["--doctest-glob=xdoc*.txt", "--doctest-glob=*.foo"]
         result = testdir.runpytest(*args)
         result.stdout.fnmatch_lines([
@@ -145,11 +145,11 @@ class TestDoctests(object):
         """
         testdir.makeini("""
             [pytest]
-            doctest_encoding={0}
+            doctest_encoding={}
         """.format(encoding))
         doctest = u"""
-            >>> u"{0}"
-            {1}
+            >>> u"{}"
+            {}
         """.format(test_string, repr(test_string))
         testdir._makefile(".txt", [doctest], {}, encoding=encoding)
 
diff --git a/testing/test_junitxml.py b/testing/test_junitxml.py
index a8f5b9fec..3c34299db 100644
--- a/testing/test_junitxml.py
+++ b/testing/test_junitxml.py
@@ -23,8 +23,8 @@ def assert_attr(node, **kwargs):
         if anode is not None:
             return anode.value
 
-    expected = dict((name, str(value)) for name, value in kwargs.items())
-    on_node = dict((name, nodeval(node, name)) for name in expected)
+    expected = {name: str(value) for name, value in kwargs.items()}
+    on_node = {name: nodeval(node, name) for name in expected}
     assert on_node == expected
 
 
@@ -1079,7 +1079,7 @@ def test_set_suite_name(testdir, suite_name):
     if suite_name:
         testdir.makeini("""
             [pytest]
-            junit_suite_name={0}
+            junit_suite_name={}
         """.format(suite_name))
         expected = suite_name
     else:
diff --git a/testing/test_mark.py b/testing/test_mark.py
index 764678ab4..f79baf0fc 100644
--- a/testing/test_mark.py
+++ b/testing/test_mark.py
@@ -744,11 +744,11 @@ class TestFunctional(object):
         to other modules.
         """
         from _pytest.mark import MarkInfo
-        items = dict((x.name, x) for x in items)
+        items = {x.name: x for x in items}
         for name, expected_markers in expected.items():
             markers = items[name].keywords._markers
-            marker_names = set([name for (name, v) in markers.items()
-                                if isinstance(v, MarkInfo)])
+            marker_names = {name for (name, v) in markers.items()
+                                if isinstance(v, MarkInfo)}
             assert marker_names == set(expected_markers)
 
     @pytest.mark.issue1540
diff --git a/testing/test_parseopt.py b/testing/test_parseopt.py
index 55983bbb1..298448a2b 100644
--- a/testing/test_parseopt.py
+++ b/testing/test_parseopt.py
@@ -90,7 +90,7 @@ class TestParser(object):
         group.addoption("--option1", "--option-1", action="store_true")
         with pytest.raises(ValueError) as err:
             group.addoption("--option1", "--option-one", action="store_true")
-        assert str(set(["--option1"])) in str(err.value)
+        assert str({"--option1"}) in str(err.value)
 
     def test_group_shortopt_lowercase(self, parser):
         group = parser.getgroup("hello")