Add 'versionadded' and move column resolvers logic to common.py.

pandas-dev · jreback · Mar 20, 2019 · Jan 26, 2019 · Jan 26, 2019 · Feb 15, 2019
commit 212506887f955b9a9ddc8a97ba89bcd56f74187b
diff --git a/pandas/core/computation/common.py b/pandas/core/computation/common.py
@@ -25,13 +25,25 @@ def _result_type_many(*arrays_and_dtypes):
         return reduce(np.result_type, arrays_and_dtypes)
 
 
-def clean_column_name_with_spaces(name):
+def _clean_column_name_with_spaces(name):
     """Check if name contains any spaces, if it contains any spaces
     the spaces will be removed and an underscore suffix is added."""
     if not isinstance(name, string_types) or " " not in name:
         return name
     return "_BACKTICK_QUOTED_STRING_" + name.replace(" ", "_")
 
 
+def _get_column_resolvers(dataFrame):
+    """Return the axis resolvers of a dataframe.
+
+    Column names with spaces are 'cleaned up' so that they can be referred to
+    by backtick quoting. See also :func:`_clean_spaces_backtick_quoted_names`
+    from :mod:`pandas.core.computation`
+    """
+
+    return {_clean_column_name_with_spaces(k): v for k, v
+            in dataFrame.iteritems()}
+
+
 class NameResolutionError(NameError):
     pass
diff --git a/pandas/core/computation/expr.py b/pandas/core/computation/expr.py
@@ -16,7 +16,7 @@
 from pandas.core import common as com
 from pandas.core.base import StringMixin
 from pandas.core.computation.common import (
-    _BACKTICK_QUOTED_STRING, clean_column_name_with_spaces)
+    _BACKTICK_QUOTED_STRING, _clean_column_name_with_spaces)
 from pandas.core.computation.ops import (
     _LOCAL_TAG, BinOp, Constant, Div, FuncNode, Op, Term, UnaryOp,
     UndefinedVariableError, _arith_ops_syms, _bool_ops_syms, _cmp_ops_syms,
@@ -117,8 +117,9 @@ def _clean_spaces_backtick_quoted_names(tok):
 
     Backtick quoted string are indicated by a certain tokval value. If a string
     is a backtick quoted token it will processed by
-    :func:`clean_column_name_with_spaces` so that the parser can find this
-    string when the query is executed. See also :meth:`DataFrame.eval`.
+    :func:`_clean_column_name_with_spaces` so that the parser can find this
+    string when the query is executed. See also :func:`_get_column_resolvers`
+    used in :meth:`DataFrame.eval`.
 
     Parameters
     ----------
@@ -132,7 +133,7 @@ def _clean_spaces_backtick_quoted_names(tok):
     """
     toknum, tokval = tok
     if toknum == _BACKTICK_QUOTED_STRING:
-        return tokenize.NAME, clean_column_name_with_spaces(tokval)
+        return tokenize.NAME, _clean_column_name_with_spaces(tokval)
     return toknum, tokval
 
 

diff --git a/pandas/core/frame.py b/pandas/core/frame.py
@@ -36,7 +36,6 @@
                            PY36, raise_with_traceback,
                            string_and_binary_types)
 from pandas.compat.numpy import function as nv
-from pandas.core.computation.common import clean_column_name_with_spaces
 from pandas.core.dtypes.cast import (
     maybe_upcast,
     cast_scalar_to_array,
@@ -2966,8 +2965,13 @@ def query(self, expr, inplace=False, **kwargs):
         expr : str
             The query string to evaluate.  You can refer to variables
             in the environment by prefixing them with an '@' character like
-            ``@a + b``. You can refer to column names with spaces by quoting
+            ``@a + b``.
+
+            .. versionadded:: 0.25.0
+
+            You can refer to column names that contain spaces by surrounding
             them in backticks like ```a a` + b``.
+
         inplace : bool
             Whether the query should modify the data in place or return
             a modified copy.
@@ -3160,13 +3164,10 @@ def eval(self, expr, inplace=False, **kwargs):
         resolvers = kwargs.pop('resolvers', None)
         kwargs['level'] = kwargs.pop('level', 0) + 1
         if resolvers is None:
+            from pandas.core.computation.common import _get_column_resolvers
+
             index_resolvers = self._get_index_resolvers()
-            # column names with spaces are altered so that they can be referred
-            # to by backtick quoting.
-            # Also see _clean_spaces_backtick_quoted_names from
-            # pandas/core/computation/expr.py
-            column_resolvers = {clean_column_name_with_spaces(k): v
-                                for k, v in self.iteritems()}
+            column_resolvers = _get_column_resolvers(self)
             resolvers = column_resolvers, index_resolvers
         if 'target' not in kwargs:
             kwargs['target'] = self