Add pylint to depot_tools.

third_party/logilab/common/deprecation.py

+# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of logilab-common.
+#
+# logilab-common is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option) any
+# later version.
+#
+# logilab-common is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with logilab-common.  If not, see <http://www.gnu.org/licenses/>.
+"""Deprecation utilities."""
+
+__docformat__ = "restructuredtext en"
+
+import sys
+from warnings import warn
+
+class class_deprecated(type):
+    """metaclass to print a warning on instantiation of a deprecated class"""
+
+    def __call__(cls, *args, **kwargs):
+        msg = getattr(cls, "__deprecation_warning__",
+                      "%(cls)s is deprecated") % {'cls': cls.__name__}
+        warn(msg, DeprecationWarning, stacklevel=2)
+        return type.__call__(cls, *args, **kwargs)
+
+
+def class_renamed(old_name, new_class, message=None):
+    """automatically creates a class which fires a DeprecationWarning
+    when instantiated.
+
+    >>> Set = class_renamed('Set', set, 'Set is now replaced by set')
+    >>> s = Set()
+    sample.py:57: DeprecationWarning: Set is now replaced by set
+      s = Set()
+    >>>
+    """
+    clsdict = {}
+    if message is None:
+        message = '%s is deprecated, use %s' % (old_name, new_class.__name__)
+    clsdict['__deprecation_warning__'] = message
+    try:
+        # new-style class
+        return class_deprecated(old_name, (new_class,), clsdict)
+    except (NameError, TypeError):
+        # old-style class
+        class DeprecatedClass(new_class):
+            """FIXME: There might be a better way to handle old/new-style class
+            """
+            def __init__(self, *args, **kwargs):
+                warn(message, DeprecationWarning, stacklevel=2)
+                new_class.__init__(self, *args, **kwargs)
+        return DeprecatedClass
+
+
+def class_moved(new_class, old_name=None, message=None):
+    """nice wrapper around class_renamed when a class has been moved into
+    another module
+    """
+    if old_name is None:
+        old_name = new_class.__name__
+    if message is None:
+        message = 'class %s is now available as %s.%s' % (
+            old_name, new_class.__module__, new_class.__name__)
+    return class_renamed(old_name, new_class, message)
+
+def deprecated(reason=None, stacklevel=2, name=None, doc=None):
+    """Decorator that raises a DeprecationWarning to print a message
+    when the decorated function is called.
+    """
+    def deprecated_decorator(func):
+        message = reason or 'The function "%s" is deprecated'
+        if '%s' in message:
+            message = message % func.func_name
+        def wrapped(*args, **kwargs):
+            warn(message, DeprecationWarning, stacklevel=stacklevel)
+            return func(*args, **kwargs)
+        try:
+            wrapped.__name__ = name or func.__name__
+        except TypeError: # readonly attribute in 2.3
+            pass
+        wrapped.__doc__ = doc or func.__doc__
+        return wrapped
+    return deprecated_decorator
+
+def moved(modpath, objname):
+    """use to tell that a callable has been moved to a new module.
+
+    It returns a callable wrapper, so that when its called a warning is printed
+    telling where the object can be found, import is done (and not before) and
+    the actual object is called.
+
+    NOTE: the usage is somewhat limited on classes since it will fail if the
+    wrapper is use in a class ancestors list, use the `class_moved` function
+    instead (which has no lazy import feature though).
+    """
+    def callnew(*args, **kwargs):
+        from logilab.common.modutils import load_module_from_name
+        message = "object %s has been moved to module %s" % (objname, modpath)
+        warn(message, DeprecationWarning, stacklevel=2)
+        m = load_module_from_name(modpath)
+        return getattr(m, objname)(*args, **kwargs)
+    return callnew
+
+