Python warnings.warn_explicit() Examples

def warn(msg, stacklevel=3):
    """Issue a warning.

    If msg is a string, :class:`.exc.SAWarning` is used as
    the category.

    .. note::

       This function is swapped out when the test suite
       runs, with a compatible version that uses
       warnings.warn_explicit, so that the warnings registry can
       be controlled.

    """
    if isinstance(msg, compat.string_types):
        warnings.warn(msg, exc.SAWarning, stacklevel=stacklevel)
    else:
        warnings.warn(msg, stacklevel=stacklevel) 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in list(options.items()):
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in list(options.items()):
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in list(options.items()):
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def show_param_warnings(app, exception):
    import inspect

    for (fname, fun), params in param_warnings.items():
        _, line = inspect.getsourcelines(fun)
        file_name = inspect.getsourcefile(fun)
        params_str = '\n'.join(f'\t{n}: {t}' for n, t in params)
        warnings.warn_explicit(
            f'\nParameters in `{fname}` have types in docstring.\n'
            f'Replace them with type annotations.\n{params_str}',
            UserWarning,
            file_name,
            line,
        )
    if param_warnings:
        raise RuntimeError('Encountered text parameter type. Use annotations.') 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in list(options.items()):
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def _unjelly_instance(self, rest):
        """
        (internal) Unjelly an instance.

        Called to handle the deprecated I{instance} token.

        @param rest: The s-expression representing the instance.

        @return: The unjellied instance.
        """
        warnings.warn_explicit(
            "Unjelly support for the instance atom is deprecated since "
            "Twisted 15.0.0.  Upgrade peer for modern instance support.",
            category=DeprecationWarning, filename="", lineno=0)

        clz = self.unjelly(rest[0])
        if not _PY3 and type(clz) is not _OldStyleClass:
            raise InsecureJelly("Legacy 'instance' found with new-style class")
        return self._genericUnjelly(clz, rest[1]) 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in list(options.items()):
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in options.items():
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def deprecated(alternative=None):
    """This is a decorator which can be used to mark functions
    as deprecated. It will result in a warning being emitted
    when the function is used."""

    def real_decorator(func):
        @functools.wraps(func)
        def new_func(*args, **kwargs):
            msg = "Call to deprecated function {0}.".format(func.__name__)
            if alternative:
                msg += " Use {0} instead".format(alternative)
            warnings.warn_explicit(
                msg,
                category=DeprecationWarning,
                filename=compat.get_function_code(func).co_filename,
                lineno=compat.get_function_code(func).co_firstlineno + 1,
            )
            return func(*args, **kwargs)

        return new_func

    return real_decorator 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in options.items():
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in list(options.items()):
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def handle_old_config(self, filename):
        warnings.warn_explicit(self.old_warning, ConfigDeprecationWarning,
                               filename, 0)
        options = self.get_section('options')
        if not self.has_section('general'):
            self.add_section('general')
        for key, value in options.items():
            if key in self.old_settings:
                section, setting = self.old_settings[key]
                if not self.has_section(section):
                    self.add_section(section)
            else:
                section = 'general'
                setting = key
            if not self.has_option(section, setting):
                self.set(section, setting, value)
        self.remove_section('options') 

def _get_calldef_exceptions(self, calldef):
        retval = []
        for decl in calldef.exceptions:
            traits = ctypeparser.TypeTraits(normalize_name(decl.partial_decl_string))
            if traits.type_is_reference:
                name = str(traits.target)
            else:
                name = str(traits.ctype)
            exc = self.type_registry.root_module.get(name, None)
            if isinstance(exc, CppException):
                retval.append(exc)
            else:
                warnings.warn_explicit("Thrown exception '%s' was not previously detected as an exception class."
                                       " PyBindGen bug?"
                                       % (normalize_name(decl.partial_decl_string)),
                                       WrapperWarning, calldef.location.file_name, calldef.location.line)
        return retval 

def deprecated(func):
    '''This is a decorator which can be used to mark functions
    as deprecated. It will result in a warning being emitted
    when the function is used.'''

    @functools.wraps(func)
    def new_func(*args, **kwargs):
        warnings.warn_explicit(
            "Call to deprecated function {}.".format(func.__name__),
            category=DeprecationWarning,
            filename=func.func_code.co_filename,
            lineno=func.func_code.co_firstlineno + 1
        )
        return func(*args, **kwargs)

    return new_func 

def deprecated(func):
    """This is a decorator which can be used to mark functions
        as deprecated. It will result in a warning being emitted
        when the function is used.
    """
    @functools.wraps(func)
    def new_func(*args, **kwargs):
        warnings.warn_explicit(
            "Call to deprecated function {}.".format(func.__name__),
            category=DeprecationWarning,
            filename=func.func_code.co_filename,
            lineno=func.func_code.co_firstlineno + 1
        )
        return func(*args, **kwargs)
    return new_func

# ---------------------------------------------------------------------
# Running external tools
# --------------------------------------------------------------------- 

def _unjelly_instance(self, rest):
        """
        (internal) Unjelly an instance.

        Called to handle the deprecated I{instance} token.

        @param rest: The s-expression representing the instance.

        @return: The unjellied instance.
        """
        warnings.warn_explicit(
            "Unjelly support for the instance atom is deprecated since "
            "Twisted 15.0.0.  Upgrade peer for modern instance support.",
            category=DeprecationWarning, filename="", lineno=0)

        clz = self.unjelly(rest[0])
        if not _PY3 and type(clz) is not _OldStyleClass:
            raise InsecureJelly("Legacy 'instance' found with new-style class")
        return self._genericUnjelly(clz, rest[1]) 

def handle_error(self, wrapper, exception, traceback_):
        if hasattr(wrapper, "gccxml_definition"):
            definition = wrapper.gccxml_definition
        elif hasattr(wrapper, "main_wrapper"):
            try:
                definition = wrapper.main_wrapper.gccxml_definition
            except AttributeError:
                definition = None
        else:
            definition = None

        if definition is None:
            print("exception %r in wrapper %s" % (exception, wrapper), file=sys.stderr)
        else:
            warnings.warn_explicit("exception %r in wrapper for %s"
                                   % (exception, definition),
                                   WrapperWarning, definition.location.file_name,
                                   definition.location.line)
        return True 

def test_once(self):
        with original_warnings.catch_warnings(record=True,
                module=self.module) as w:
            self.module.resetwarnings()
            self.module.filterwarnings("once", category=UserWarning)
            message = UserWarning("FilterTests.test_once")
            self.module.warn_explicit(message, UserWarning, "__init__.py",
                                    42)
            self.assertEqual(w[-1].message, message)
            del w[:]
            self.module.warn_explicit(message, UserWarning, "__init__.py",
                                    13)
            self.assertEqual(len(w), 0)
            self.module.warn_explicit(message, UserWarning, "test_warnings2.py",
                                    42)
            self.assertEqual(len(w), 0) 

def test_once(self):
        with original_warnings.catch_warnings(record=True,
                module=self.module) as w:
            self.module.resetwarnings()
            self.module.filterwarnings("once", category=UserWarning)
            message = UserWarning("FilterTests.test_once")
            self.module.warn_explicit(message, UserWarning, "test_warnings.py",
                                    42)
            self.assertEqual(w[-1].message, message)
            del w[:]
            self.module.warn_explicit(message, UserWarning, "test_warnings.py",
                                    13)
            self.assertEqual(len(w), 0)
            self.module.warn_explicit(message, UserWarning, "test_warnings2.py",
                                    42)
            self.assertEqual(len(w), 0) 

def __call__(self, func):
        msg = "Call to deprecated function {}".format(func.__name__)
        if self.use_instead:
            msg += '; use ' + self.use_instead + ' instead'

        def wrapper(*args, **kwargs):
            fingerprint = (func.__name__, func.__code__.co_filename, func.__code__.co_firstlineno)
            if fingerprint not in self.seen:
                warnings.warn_explicit(
                    msg,
                    category=DeprecationWarning,
                    filename=func.__code__.co_filename,
                    lineno=func.__code__.co_firstlineno + 1)
            self.seen.update([fingerprint])
            return func(*args, **kwargs)

        wrapper.__doc__ = "Deprecated"
        if self.use_instead:
            wrapper.__doc__ += '; use ' + self.use_instead + ' instead'
        return wrapper 

def test_once(self):
        with original_warnings.catch_warnings(record=True,
                module=self.module) as w:
            self.module.resetwarnings()
            self.module.filterwarnings("once", category=UserWarning)
            message = UserWarning("FilterTests.test_once")
            self.module.warn_explicit(message, UserWarning, "__init__.py",
                                    42)
            self.assertEqual(w[-1].message, message)
            del w[:]
            self.module.warn_explicit(message, UserWarning, "__init__.py",
                                    13)
            self.assertEqual(len(w), 0)
            self.module.warn_explicit(message, UserWarning, "test_warnings2.py",
                                    42)
            self.assertEqual(len(w), 0) 

def deprecated(func):
  '''This is a decorator which can be used to mark functions
  as deprecated. It will result in a warning being emitted
  when the function is used.'''

  @functools.wraps(func)
  def new_func(*args, **kwargs):
    warnings.warn_explicit(
      "Call to deprecated function {}.".format(func.__name__),
      category=DeprecationWarning,
      filename=func.func_code.co_filename,
      lineno=func.func_code.co_firstlineno + 1
    )
    return func(*args, **kwargs)

  return new_func 

def deprecated(func):
    """This is a decorator which can be used to mark functions
    as deprecated. It will result in a warning being emitted
    when the function is used.
    """

    @functools.wraps(func)
    def new_func(*args, **kwargs):
        warnings.simplefilter("always", DeprecationWarning)  # turn off filter
        warnings.warn_explicit(
            "Call to deprecated function {}.".format(func.__name__),
            category=DeprecationWarning,
            filename=func.__code__.co_filename,
            lineno=func.__code__.co_firstlineno + 1,
        )
        warnings.simplefilter("default", DeprecationWarning)  # reset filter
        logger.warn(
            "%s - DeprecationWarning: Call to deprecated function %s. %s:%s"
            % (datetime.datetime.now(), func.__name__, func.__code__.co_filename, func.__code__.co_firstlineno + 1)
        )
        return func(*args, **kwargs)

    return new_func 

def deprecated(version, version_removed):
    '''This is a decorator which can be used to mark functions
    as deprecated.

    It will result in a warning being emitted when the function is used.'''

    def __wrapper(func, *args, **kwargs):
        '''Warn the user, and then proceed.'''
        code = six.get_function_code(func)
        warnings.warn_explicit(
            "{:s}.{:s}\n\tDeprecated as of JAMS version {:s}."
            "\n\tIt will be removed in JAMS version {:s}."
            .format(func.__module__, func.__name__,
                    version, version_removed),
            category=DeprecationWarning,
            filename=code.co_filename,
            lineno=code.co_firstlineno + 1
        )
        return func(*args, **kwargs)

    return decorator(__wrapper) 

def _selectVerifyImplementation():
    """
    Determine if C{service_identity} is installed. If so, use it. If not, use
    simplistic and incorrect checking as implemented in
    L{simpleVerifyHostname}.

    @return: 2-tuple of (C{verify_hostname}, C{VerificationError})
    @rtype: L{tuple}
    """

    whatsWrong = (
        "Without the service_identity module, Twisted can perform only "
        "rudimentary TLS client hostname verification.  Many valid "
        "certificate/hostname mappings may be rejected."
    )

    try:
        from service_identity import VerificationError
        from service_identity.pyopenssl import (
            verify_hostname, verify_ip_address
        )
        return verify_hostname, verify_ip_address, VerificationError
    except ImportError as e:
        warnings.warn_explicit(
            "You do not have a working installation of the "
            "service_identity module: '" + str(e) + "'.  "
            "Please install it from "
            "<https://pypi.python.org/pypi/service_identity> and make "
            "sure all of its dependencies are satisfied.  "
            + whatsWrong,
            # Unfortunately the lineno is required.
            category=UserWarning, filename="", lineno=0)

    return simpleVerifyHostname, simpleVerifyIPAddress, SimpleVerificationError 

def test_module_all_attribute(self):
        self.assertTrue(hasattr(self.module, '__all__'))
        target_api = ["warn", "warn_explicit", "showwarning",
                      "formatwarning", "filterwarnings", "simplefilter",
                      "resetwarnings", "catch_warnings"]
        self.assertSetEqual(set(self.module.__all__),
                            set(target_api)) 

def test_mutate_filter_list(self):
        class X:
            def match(self, a):
                L[:] = []

        L = [("default",X(),UserWarning,X(),0) for i in range(2)]
        with original_warnings.catch_warnings(record=True,
                module=self.module) as w:
            self.module.filters = L
            self.module.warn_explicit(UserWarning("b"), None, "f.py", 42)
            self.assertEqual(str(w[-1].message), "b") 

def test_module_all_attribute(self):
        self.assertTrue(hasattr(self.module, '__all__'))
        target_api = ["warn", "warn_explicit", "showwarning",
                      "formatwarning", "filterwarnings", "simplefilter",
                      "resetwarnings", "catch_warnings"]
        self.assertSetEqual(set(self.module.__all__),
                            set(target_api)) 

def deprecated(func):
    '''This is a decorator which can be used to mark functions
    as deprecated. It will result in a warning being emitted
    when the function is used.'''

    @functools.wraps(func)
    def new_func(*args, **kwargs):
        warnings.warn_explicit(
            "Call to deprecated function {}.".format(func.__name__),
            category=DeprecationWarning,
            filename=func.__code__.co_filename,
            lineno=func.__code__.co_firstlineno + 1
        )
        return func(*args, **kwargs)
    new_func.__name__ = func.__name__
    new_func.__doc__ = func.__doc__
    new_func.__dict__.update(func.__dict__)
    return new_func

# ## Usage examples ##
# @deprecated
# def my_func():
#     pass

# @other_decorators_must_be_upper
# @deprecated
# def my_func():
#     pass