<p dir="auto">These can be seen by inspecting the <code class="notranslate">__call__</code> attribute, but they are referenced from the particular plotting methods, but not easily learned about in IPython/Jupyter.</p>
<p dir="auto"><a href="https://github.com/pandas-dev/pandas/blob/master/pandas/tools/plotting.py#L3781">https://github.com/pandas-dev/pandas/blob/master/pandas/tools/plotting.py#L3781</a></p>
<p dir="auto">I'm running into a problem with using <code class="notranslate">dropna</code> with a list of columns specified by <code class="notranslate">subset</code>. I wish to remove rows with missing values:</p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://camo.githubusercontent.com/a2925527d468f0050b1cb35e254876beef367322970b06ece2aa2a00aa94da0c/687474703a2f2f642e70722f692f357767522b"><img src="https://camo.githubusercontent.com/a2925527d468f0050b1cb35e254876beef367322970b06ece2aa2a00aa94da0c/687474703a2f2f642e70722f692f357767522b" alt="missing" data-canonical-src="http://d.pr/i/5wgR+" style="max-width: 100%;"></a></p>
<p dir="auto">The dataset looks like this:</p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://camo.githubusercontent.com/b97fbb7c01e51f97f5e0d38ecc218bd879d79066969def568bbe086ae08cc966/687474703a2f2f642e70722f692f775259452b"><img src="https://camo.githubusercontent.com/b97fbb7c01e51f97f5e0d38ecc218bd879d79066969def568bbe086ae08cc966/687474703a2f2f642e70722f692f775259452b" alt="dataset" data-canonical-src="http://d.pr/i/wRYE+" style="max-width: 100%;"></a></p>
<p dir="auto">However, when I try to call <code class="notranslate">dropna</code> using these columns, it complains about a duplicate axis:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="variables.dropna(subset=['cigarette_smokers', 'birth_wt_child', 
                                 'oxygen', 'length_of_stay', 'hospitalized_vitamin_d', 'breastfed'])

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
&lt;ipython-input-168-96be0b0b00e8&gt; in &lt;module&gt;()
      1 variables.dropna(subset=['cigarette_smokers', 'birth_wt_child', 
----&gt; 2                                      'oxygen', 'length_of_stay', 'hospitalized_vitamin_d', 'breastfed'])

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in dropna(self, axis, how, thresh, subset, inplace)
   2407             if subset is not None:
   2408                 agg_axis_name = self._get_axis_name(agg_axis)
-&gt; 2409                 agg_obj = self.reindex(**{agg_axis_name: subset})
   2410 
   2411             count = agg_obj.count(axis=agg_axis)

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in reindex(self, index, columns, **kwargs)
   2160     def reindex(self, index=None, columns=None, **kwargs):
   2161         return super(DataFrame, self).reindex(index=index, columns=columns,
-&gt; 2162                                               **kwargs)
   2163 
   2164     @Appender(_shared_docs['reindex_axis'] % _shared_doc_kwargs)

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/generic.pyc in reindex(self, *args, **kwargs)
   1561         return self._reindex_axes(axes, level, limit,
   1562                                   method, fill_value, copy,
-&gt; 1563                                   takeable=takeable).__finalize__(self)
   1564 
   1565     def _reindex_axes(self, axes, level, limit, method, fill_value, copy,

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in _reindex_axes(self, axes, level, limit, method, fill_value, copy, takeable)
   2110         if columns is not None:
   2111             frame = frame._reindex_columns(columns, copy, level, fill_value,
-&gt; 2112                                            limit, takeable=takeable)
   2113 
   2114         index = axes['index']

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in _reindex_columns(self, new_columns, copy, level, fill_value, limit, takeable)
   2137         return self._reindex_with_indexers({1: [new_columns, indexer]},
   2138                                            copy=copy, fill_value=fill_value,
-&gt; 2139                                            allow_dups=takeable)
   2140 
   2141     def _reindex_multi(self, axes, copy, fill_value):

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/generic.pyc in _reindex_with_indexers(self, reindexers, method, fill_value, limit, copy, allow_dups)
   1687                 new_data = new_data.reindex_indexer(index, indexer, axis=baxis,
   1688                                                     fill_value=fill_value,
-&gt; 1689                                                     allow_dups=allow_dups)
   1690 
   1691             elif (baxis == 0 and index is not None and

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/internals.pyc in reindex_indexer(self, new_axis, indexer, axis, fill_value, allow_dups)
   3227         # trying to reindex on an axis with duplicates
   3228         if not allow_dups and not self.axes[axis].is_unique:
-&gt; 3229             raise ValueError(&quot;cannot reindex from a duplicate axis&quot;)
   3230 
   3231         if not self.is_consolidated():

ValueError: cannot reindex from a duplicate axis"><pre class="notranslate"><code class="notranslate">variables.dropna(subset=['cigarette_smokers', 'birth_wt_child', 
                                 'oxygen', 'length_of_stay', 'hospitalized_vitamin_d', 'breastfed'])

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
&lt;ipython-input-168-96be0b0b00e8&gt; in &lt;module&gt;()
      1 variables.dropna(subset=['cigarette_smokers', 'birth_wt_child', 
----&gt; 2                                      'oxygen', 'length_of_stay', 'hospitalized_vitamin_d', 'breastfed'])

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in dropna(self, axis, how, thresh, subset, inplace)
   2407             if subset is not None:
   2408                 agg_axis_name = self._get_axis_name(agg_axis)
-&gt; 2409                 agg_obj = self.reindex(**{agg_axis_name: subset})
   2410 
   2411             count = agg_obj.count(axis=agg_axis)

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in reindex(self, index, columns, **kwargs)
   2160     def reindex(self, index=None, columns=None, **kwargs):
   2161         return super(DataFrame, self).reindex(index=index, columns=columns,
-&gt; 2162                                               **kwargs)
   2163 
   2164     @Appender(_shared_docs['reindex_axis'] % _shared_doc_kwargs)

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/generic.pyc in reindex(self, *args, **kwargs)
   1561         return self._reindex_axes(axes, level, limit,
   1562                                   method, fill_value, copy,
-&gt; 1563                                   takeable=takeable).__finalize__(self)
   1564 
   1565     def _reindex_axes(self, axes, level, limit, method, fill_value, copy,

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in _reindex_axes(self, axes, level, limit, method, fill_value, copy, takeable)
   2110         if columns is not None:
   2111             frame = frame._reindex_columns(columns, copy, level, fill_value,
-&gt; 2112                                            limit, takeable=takeable)
   2113 
   2114         index = axes['index']

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in _reindex_columns(self, new_columns, copy, level, fill_value, limit, takeable)
   2137         return self._reindex_with_indexers({1: [new_columns, indexer]},
   2138                                            copy=copy, fill_value=fill_value,
-&gt; 2139                                            allow_dups=takeable)
   2140 
   2141     def _reindex_multi(self, axes, copy, fill_value):

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/generic.pyc in _reindex_with_indexers(self, reindexers, method, fill_value, limit, copy, allow_dups)
   1687                 new_data = new_data.reindex_indexer(index, indexer, axis=baxis,
   1688                                                     fill_value=fill_value,
-&gt; 1689                                                     allow_dups=allow_dups)
   1690 
   1691             elif (baxis == 0 and index is not None and

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/internals.pyc in reindex_indexer(self, new_axis, indexer, axis, fill_value, allow_dups)
   3227         # trying to reindex on an axis with duplicates
   3228         if not allow_dups and not self.axes[axis].is_unique:
-&gt; 3229             raise ValueError("cannot reindex from a duplicate axis")
   3230 
   3231         if not self.is_consolidated():

ValueError: cannot reindex from a duplicate axis
</code></pre></div>
<p dir="auto">Running a current build from master in Python 2.7.5 on OS X 10.9.1.</p>