Remove unused/unneeded code

src/_pytest/python.py

@@ -1170,8 +1170,6 @@ def _idval(val, argname, idx, idfn, item, config):
             # See issue https://github.com/pytest-dev/pytest/issues/2169
             msg = "{}: error raised while trying to determine id of parameter '{}' at position {}\n"
             msg = msg.format(item.nodeid, argname, idx)
-            # we only append the exception type and message because on Python 2 reraise does nothing
-            msg += "  {}: {}\n".format(type(e).__name__, e)
             raise ValueError(msg) from e
     elif config:
         hook_id = config.hook.pytest_make_parametrize_id(

src/_pytest/python_api.py

@@ -20,20 +20,6 @@ from _pytest.outcomes import fail
 BASE_TYPE = (type, STRING_TYPES)
 
 
-def _cmp_raises_type_error(self, other):
-    """__cmp__ implementation which raises TypeError. Used
-    by Approx base classes to implement only == and != and raise a
-    TypeError for other comparisons.
-
-    Needed in Python 2 only, Python 3 all it takes is not implementing the
-    other operators at all.
-    """
-    __tracebackhide__ = True
-    raise TypeError(
-        "Comparison operators other than == and != not supported by approx objects"
-    )
-
-
 def _non_numeric_type_error(value, at):
     at_str = " at {}".format(at) if at else ""
     return TypeError(

testing/python/metafunc.py

@@ -506,8 +506,8 @@ class TestMetafunc:
         result = testdir.runpytest()
         result.stdout.fnmatch_lines(
             [
-                "*test_foo: error raised while trying to determine id of parameter 'arg' at position 0",
                 "*Exception: bad ids",
+                "*test_foo: error raised while trying to determine id of parameter 'arg' at position 0",
             ]
         )