Signature rewriting

pandas-dev · jorisvandenbossche · Oct 27, 2017 · Oct 24, 2017 · Oct 24, 2017 · Oct 24, 2017
commit 44e01da43668051b2b3cbda469c9c90f087c6be6
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
@@ -82,7 +82,8 @@
 from pandas import compat
 from pandas.compat import PY36
 from pandas.compat.numpy import function as nv
-from pandas.util._decorators import Appender, Substitution
+from pandas.util._decorators import (Appender, Substitution,
+                                     rewrite_axis_style_signature)
 from pandas.util._validators import validate_bool_kwarg
 
 from pandas.core.indexes.period import PeriodIndex
@@ -2917,6 +2918,12 @@ def align(self, other, join='outer', axis=None, level=None, copy=True,
                                             broadcast_axis=broadcast_axis)
 
     @Appender(_shared_docs['reindex'] % _shared_doc_kwargs)
+    @rewrite_axis_style_signature('labels', [('method', None),
+                                             ('copy', True),
+                                             ('level', None),
+                                             ('fill_value', np.nan),
+                                             ('limit', None),
+                                             ('tolerance', None)])
     def reindex(self, *args, **kwargs):
         axes = self._validate_axis_style_args(args, kwargs, 'labels',
                                               'reindex')
@@ -2933,6 +2940,9 @@ def reindex_axis(self, labels, axis=0, method=None, level=None, copy=True,
                                         method=method, level=level, copy=copy,
                                         limit=limit, fill_value=fill_value)
 
+    @rewrite_axis_style_signature('mapper', [('copy', True),
+                                             ('inplace', False),
+                                             ('level', None)])
     def rename(self, *args, **kwargs):
         """Alter axes labels.
 

diff --git a/pandas/tests/frame/test_alter_axes.py b/pandas/tests/frame/test_alter_axes.py
@@ -2,13 +2,14 @@
 
 from __future__ import print_function
 
+import inspect
 import pytest
 
 from datetime import datetime, timedelta
 
 import numpy as np
 
-from pandas.compat import lrange
+from pandas.compat import lrange, PY2
 from pandas import (DataFrame, Series, Index, MultiIndex,
                     RangeIndex, date_range, IntervalIndex,
                     to_datetime)
@@ -998,6 +999,21 @@ def test_ambiguous_warns(self):
         with tm.assert_produces_warning(UserWarning):
             df.rename({0: 10}, {"A": "B"})
 
+    @pytest.mark.skipif(PY2, reason="inspect.signature")
+    def test_rename_signature(self):
+        sig = inspect.signature(pd.DataFrame.rename)
+        parameters = set(sig.parameters)
+        assert parameters == {"self", "mapper", "index", "columns", "axis",
+                              "inplace", "copy", "level"}
+
+    @pytest.mark.skipif(PY2, reason="inspect.signature")
+    def test_reindex_signature(self):
+        sig = inspect.signature(pd.DataFrame.reindex)
+        parameters = set(sig.parameters)
+        assert parameters == {"self", "labels", "index", "columns", "axis",
+                              "limit", "copy", "level", "method",
+                              "fill_value", "tolerance"}
+
 
 class TestIntervalIndex(object):
 

diff --git a/pandas/util/_decorators.py b/pandas/util/_decorators.py
@@ -1,5 +1,6 @@
-from pandas.compat import callable, signature
+from pandas.compat import callable, signature, PY2
 from pandas._libs.properties import cache_readonly  # noqa
+import inspect
 import types
 import warnings
 from textwrap import dedent
@@ -122,6 +123,31 @@ def wrapper(*args, **kwargs):
 # Substitution and Appender are derived from matplotlib.docstring (1.1.0)
 # module http://matplotlib.org/users/license.html
 
+def rewrite_axis_style_signature(name, extra_params):
+    def decorate(func):
+        @wraps(func)
+        def wrapper(*args, **kwargs):
+            return func(*args, **kwargs)
+
+        if not PY2:
+            kind = inspect.Parameter.POSITIONAL_OR_KEYWORD
+            params = [
+                inspect.Parameter('self', kind),
+                inspect.Parameter(name, kind, default=None),
+                inspect.Parameter('index', kind, default=None),
+                inspect.Parameter('columns', kind, default=None),
+                inspect.Parameter('axis', kind, default=None),
+            ]
+
+            for pname, default in extra_params:
+                params.append(inspect.Parameter(pname, kind, default=default))
+
+            sig = inspect.Signature(params)
+
+            func.__signature__ = sig
+        return wrapper
+    return decorate
+
 
 class Substitution(object):
     """