Changed handling of decorators for classes in python 2.7

CHANGELOG.rst

@@ -1,3 +1,31 @@
+v0.2.3
+======
+This minor release contains some backward incompatible changes on how to handle
+the decorators for classes in python 2.7. Thanks
+`@lesteve <https://github.com/lesteve>`__ and
+`@guillaumeeb <https://github.com/guillaumeeb>`__ for your input on this.
+
+Changed
+-------
+* When using the decorators for classes in python 2.7, e.g. via::
+
+      >>> @docstrings
+      ... class Something(object):
+      ...     "%(replacement)s"
+
+  it does not have an effect anymore. This is because class docstrings cannot
+  be modified in python 2.7 (see issue
+  `#5 <https://github.com/Chilipp/docrep/issues/5#>`__). The original behaviour
+  was to raise an error. You can restore the old behaviour by setting
+  `DocstringProcessor.python2_classes = 'raise'`.
+* Some docs have been updated (see PR
+  `#7 <https://github.com/Chilipp/docrep/pull/7>`__)
+
+Added
+-----
+* the `DocstringProcessor.python2_classes` to change the handling of classes
+  in python 2.7
+
 v0.2.2
 ======
 Added

docrep/__init__.py

@@ -1,10 +1,11 @@
 import types
 import six
+import inspect
 import re
 from warnings import warn
 
 
-__version__ = '0.2.2'
+__version__ = '0.2.3'
 
 __author__ = 'Philipp Sommer'
 
@@ -226,6 +227,19 @@ class DocstringProcessor(object):
     text_sections = ['Warnings', 'Notes', 'Examples', 'See Also',
                      'References']
 
+    #: The action on how to react on classes in python 2
+    #:
+    #: When calling::
+    #:
+    #:     >>> @docstrings
+    #:     ... class NewClass(object):
+    #:     ...     """%(replacement)s"""
+    #:
+    #: This normaly raises an AttributeError, because the ``__doc__`` attribute
+    #: of a class in python 2 is not writable. This attribute may be one of
+    #: ``'ignore', 'raise' or 'warn'``
+    python2_classes = 'ignore'
+
     def __init__(self, *args, **kwargs):
         """
     Parameters
@@ -256,9 +270,22 @@ def __init__(self, *args, **kwargs):
         self.patterns = patterns
 
     def __call__(self, func):
-        func.__doc__ = func.__doc__ and safe_modulo(func.__doc__, self.params,
-                                                    stacklevel=3)
-        return func
+        """
+        Substitute in a docstring of a function with :attr:`params`
+
+        Parameters
+        ----------
+        func: function
+            function with the documentation whose sections
+            shall be inserted from the :attr:`params` attribute
+
+        See Also
+        --------
+        dedent: also dedents the doc
+        with_indent: also indents the doc"""
+        doc = func.__doc__ and safe_modulo(func.__doc__, self.params,
+                                           stacklevel=3)
+        return self._set_object_doc(func, doc)
 
     def get_sections(self, s, base,
                      sections=['Parameters', 'Other Parameters']):
@@ -342,6 +369,23 @@ def func(f):
             return f
         return func
 
+    def _set_object_doc(self, obj, doc, stacklevel=3):
+        """Convenience method to set the __doc__ attribute of a python object
+        """
+        if isinstance(obj, types.MethodType) and six.PY2:
+            obj = obj.im_func
+        try:
+            obj.__doc__ = doc
+        except AttributeError:  # probably python2 class
+            if (self.python2_classes != 'raise' and
+                    (inspect.isclass(obj) and six.PY2)):
+                if self.python2_classes == 'warn':
+                    warn("Cannot modify docstring of classes in python2!",
+                         stacklevel=stacklevel)
+            else:
+                raise
+        return obj
+
     def dedent(self, func):
         """
         Dedent the docstring of a function and substitute with :attr:`params`
@@ -351,11 +395,8 @@ def dedent(self, func):
         func: function
             function with the documentation to dedent and whose sections
             shall be inserted from the :attr:`params` attribute"""
-        if isinstance(func, types.MethodType) and not six.PY3:
-            func = func.im_func
-        func.__doc__ = func.__doc__ and self.dedents(func.__doc__,
-                                                     stacklevel=4)
-        return func
+        doc = func.__doc__ and self.dedents(func.__doc__, stacklevel=4)
+        return self._set_object_doc(func, doc)
 
     def dedents(self, s, stacklevel=3):
         """
@@ -373,15 +414,51 @@ def dedents(self, s, stacklevel=3):
         return safe_modulo(s, self.params, stacklevel=stacklevel)
 
     def with_indent(self, indent=0):
+        """
+        Substitute in the docstring of a function with indented :attr:`params`
+
+        Parameters
+        ----------
+        indent: int
+            The number of spaces that the substitution should be indented
+
+        Returns
+        -------
+        function
+            Wrapper that takes a function as input and substitutes it's
+            ``__doc__`` with the indented versions of :attr:`params`
+
+        See Also
+        --------
+        with_indents, dedent"""
         def replace(func):
-            if isinstance(func, types.MethodType) and not six.PY3:
-                func = func.im_func
-            func.__doc__ = func.__doc__ and self.with_indents(
+            doc = func.__doc__ and self.with_indents(
                 func.__doc__, indent=indent, stacklevel=4)
-            return func
+            return self._set_object_doc(func, doc)
         return replace
 
     def with_indents(self, s, indent=0, stacklevel=3):
+        """
+        Substitute a string with the indented :attr:`params`
+
+        Parameters
+        ----------
+        s: str
+            The string in which to substitute
+        indent: int
+            The number of spaces that the substitution should be indented
+        stacklevel: int
+            The stacklevel for the warning raised in :func:`safe_module` when
+            encountering an invalid key in the string
+
+        Returns
+        -------
+        str
+            The substituted string
+
+        See Also
+        --------
+        with_indent, dedents"""
         # we make a new dictionary with objects that indent the original
         # strings if necessary. Note that the first line is not indented
         d = {key: _StrWithIndentation(val, indent)

docs/conf.py

@@ -388,7 +388,7 @@
     'pandas': ('http://pandas.pydata.org/pandas-docs/stable/', None),
     'numpy': ('http://docs.scipy.org/doc/numpy/', None),
     'matplotlib': ('http://matplotlib.org/', None),
-    'sphinx': ('http://sphinx-doc.org/', None),
+    'sphinx': ('http://www.sphinx-doc.org/en/stable/', None),
     'xarray': ('http://xarray.pydata.org/en/stable/', None),
     'cartopy': ('http://scitools.org.uk/cartopy/docs/latest/', None),
     'mpl_toolkits': ('http://matplotlib.org/basemap/', None),

docs/index.rst

@@ -234,6 +234,29 @@ or from the source on github_ via::
 .. _github: https://github.com/Chilipp/docrep
 
 
+.. note::
+
+    When using docrep in python 2.7, there is to mention that the ``__doc__``
+    attribute of classes is not writable, so something like
+
+    .. ipython::
+
+        In [12]: @docstrings
+           ....: class SomeClass(object):
+           ....:     """An awesome class
+           ....:
+           ....:     Parameters
+           ....:     ----------
+           ....:     %(repeated.parameters)s
+           ....:     """
+
+    would raise an error. There are several workarounds (see
+    `the issue on github <https://github.com/Chilipp/docrep/issues/5#>`__) but the
+    default for python 2.7 is, to simply not modify class docstrings. You
+    can, however, change this behaviour using the
+    :attr:`DocstringProcessor.python2_classes` attribute.
+
+
 API Reference
 =============
 

setup.py

@@ -11,7 +11,7 @@ def readme():
 
 
 setup(name='docrep',
-      version='0.2.2',
+      version='0.2.3',
       description='Python package for docstring repetition',
       long_description=readme(),
       classifiers=[
@@ -24,6 +24,7 @@ def readme():
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
         'Operating System :: OS Independent',
       ],
       keywords='docstrings docs docstring napoleon numpy reStructured text',

tests/test_docrep.py

@@ -592,6 +592,24 @@ def test_delete_kwargs(self):
         with self.assertWarns(UserWarning):
             self.ds.delete_kwargs('test')
 
+    @unittest.skipIf(not six.PY2, "Only implemented for python 2.7")
+    def test_py2_classes(self):
+        """Test the handling of classes in python 2.7"""
+        # this should work
+        @self.ds
+        class Test(object):
+            """docs"""
+        # this should not
+        self.ds.python2_classes = 'raise'
+        try:
+            @self.ds
+            class Test2(object):
+                """docs"""
+        except AttributeError:
+            pass
+        else:
+            self.fail("Should have raised AttributeError!")
+
 
 if __name__ == '__main__':
     unittest.main()