CLN: de-privatize names in core.computation (#29665)

Author: jbrockmendel

pandas/core/computation/align.py

@@ -8,10 +8,11 @@
 
 from pandas.errors import PerformanceWarning
 
-import pandas as pd
+from pandas.core.dtypes.generic import ABCDataFrame, ABCSeries
+
 from pandas.core.base import PandasObject
 import pandas.core.common as com
-from pandas.core.computation.common import _result_type_many
+from pandas.core.computation.common import result_type_many
 
 
 def _align_core_single_unary_op(term):
@@ -49,7 +50,7 @@ def wrapper(terms):
 
         # we don't have any pandas objects
         if not _any_pandas_objects(terms):
-            return _result_type_many(*term_values), None
+            return result_type_many(*term_values), None
 
         return f(terms)
 
@@ -60,7 +61,10 @@ def wrapper(terms):
 def _align_core(terms):
     term_index = [i for i, term in enumerate(terms) if hasattr(term.value, "axes")]
     term_dims = [terms[i].value.ndim for i in term_index]
-    ndims = pd.Series(dict(zip(term_index, term_dims)))
+
+    from pandas import Series
+
+    ndims = Series(dict(zip(term_index, term_dims)))
 
     # initial axes are the axes of the largest-axis'd term
     biggest = terms[ndims.idxmax()].value
@@ -70,7 +74,7 @@ def _align_core(terms):
     gt_than_one_axis = naxes > 1
 
     for value in (terms[i].value for i in term_index):
-        is_series = isinstance(value, pd.Series)
+        is_series = isinstance(value, ABCSeries)
         is_series_and_gt_one_axis = is_series and gt_than_one_axis
 
         for axis, items in enumerate(value.axes):
@@ -87,7 +91,7 @@ def _align_core(terms):
             ti = terms[i].value
 
             if hasattr(ti, "reindex"):
-                transpose = isinstance(ti, pd.Series) and naxes > 1
+                transpose = isinstance(ti, ABCSeries) and naxes > 1
                 reindexer = axes[naxes - 1] if transpose else items
 
                 term_axis_size = len(ti.axes[axis])
@@ -111,28 +115,28 @@ def _align_core(terms):
     return typ, _zip_axes_from_type(typ, axes)
 
 
-def _align(terms):
+def align_terms(terms):
     """Align a set of terms"""
     try:
         # flatten the parse tree (a nested list, really)
         terms = list(com.flatten(terms))
     except TypeError:
         # can't iterate so it must just be a constant or single variable
-        if isinstance(terms.value, pd.core.generic.NDFrame):
+        if isinstance(terms.value, (ABCSeries, ABCDataFrame)):
             typ = type(terms.value)
             return typ, _zip_axes_from_type(typ, terms.value.axes)
         return np.result_type(terms.type), None
 
     # if all resolved variables are numeric scalars
     if all(term.is_scalar for term in terms):
-        return _result_type_many(*(term.value for term in terms)).type, None
+        return result_type_many(*(term.value for term in terms)).type, None
 
     # perform the main alignment
     typ, axes = _align_core(terms)
     return typ, axes
 
 
-def _reconstruct_object(typ, obj, axes, dtype):
+def reconstruct_object(typ, obj, axes, dtype):
     """
     Reconstruct an object given its type, raw value, and possibly empty
     (None) axes.

pandas/core/computation/common.py

@@ -15,7 +15,7 @@ def _ensure_decoded(s):
     return s
 
 
-def _result_type_many(*arrays_and_dtypes):
+def result_type_many(*arrays_and_dtypes):
     """ wrapper around numpy.result_type which overcomes the NPY_MAXARGS (32)
     argument limit """
     try:

pandas/core/computation/engines.py

@@ -4,7 +4,7 @@
 
 import abc
 
-from pandas.core.computation.align import _align, _reconstruct_object
+from pandas.core.computation.align import align_terms, reconstruct_object
 from pandas.core.computation.ops import UndefinedVariableError, _mathops, _reductions
 
 import pandas.io.formats.printing as printing
@@ -67,11 +67,11 @@ def evaluate(self):
             The result of the passed expression.
         """
         if not self._is_aligned:
-            self.result_type, self.aligned_axes = _align(self.expr.terms)
+            self.result_type, self.aligned_axes = align_terms(self.expr.terms)
 
         # make sure no names in resolvers and locals/globals clash
         res = self._evaluate()
-        return _reconstruct_object(
+        return reconstruct_object(
             self.result_type, res, self.aligned_axes, self.expr.terms.return_type
         )
 

pandas/core/computation/eval.py

@@ -10,6 +10,7 @@
 from pandas.util._validators import validate_bool_kwarg
 
 from pandas.core.computation.engines import _engines
+from pandas.core.computation.expr import Expr, _parsers, tokenize_string
 from pandas.core.computation.scope import _ensure_scope
 
 from pandas.io.formats.printing import pprint_thing
@@ -64,7 +65,7 @@ def _check_engine(engine):
     return engine
 
 
-def _check_parser(parser):
+def _check_parser(parser: str):
     """
     Make sure a valid parser is passed.
 
@@ -77,7 +78,6 @@ def _check_parser(parser):
     KeyError
       * If an invalid parser is passed
     """
-    from pandas.core.computation.expr import _parsers
 
     if parser not in _parsers:
         raise KeyError(
@@ -115,7 +115,7 @@ def _check_expression(expr):
         raise ValueError("expr cannot be an empty string")
 
 
-def _convert_expression(expr):
+def _convert_expression(expr) -> str:
     """
     Convert an object to an expression.
 
@@ -131,7 +131,7 @@ def _convert_expression(expr):
 
     Returns
     -------
-    s : unicode
+    str
         The string representation of an object.
 
     Raises
@@ -144,8 +144,7 @@ def _convert_expression(expr):
     return s
 
 
-def _check_for_locals(expr, stack_level, parser):
-    from pandas.core.computation.expr import tokenize_string
+def _check_for_locals(expr: str, stack_level: int, parser: str):
 
     at_top_of_stack = stack_level == 0
     not_pandas_parser = parser != "pandas"
@@ -192,7 +191,7 @@ def eval(
 
     Parameters
     ----------
-    expr : str or unicode
+    expr : str
         The expression to evaluate. This string cannot contain any Python
         `statements
         <https://docs.python.org/3/reference/simple_stmts.html#simple-statements>`__,
@@ -282,7 +281,6 @@ def eval(
     See the :ref:`enhancing performance <enhancingperf.eval>` documentation for
     more details.
     """
-    from pandas.core.computation.expr import Expr
 
     inplace = validate_bool_kwarg(inplace, "inplace")
 

pandas/core/computation/expr.py

@@ -11,7 +11,6 @@
 
 import numpy as np
 
-import pandas as pd
 import pandas.core.common as com
 from pandas.core.computation.common import (
     _BACKTICK_QUOTED_STRING,
@@ -40,7 +39,7 @@
 import pandas.io.formats.printing as printing
 
 
-def tokenize_string(source):
+def tokenize_string(source: str):
     """
     Tokenize a Python source code string.
 
@@ -171,7 +170,7 @@ def _compose(*funcs):
 
 
 def _preparse(
-    source,
+    source: str,
     f=_compose(
         _replace_locals,
         _replace_booleans,
@@ -600,6 +599,8 @@ def visit_Index(self, node, **kwargs):
         return self.visit(node.value)
 
     def visit_Subscript(self, node, **kwargs):
+        import pandas as pd
+
         value = self.visit(node.value)
         slobj = self.visit(node.slice)
         result = pd.eval(

pandas/core/computation/ops.py

@@ -13,7 +13,7 @@
 from pandas.core.dtypes.common import is_list_like, is_scalar
 
 import pandas.core.common as com
-from pandas.core.computation.common import _ensure_decoded, _result_type_many
+from pandas.core.computation.common import _ensure_decoded, result_type_many
 from pandas.core.computation.scope import _DEFAULT_GLOBALS
 
 from pandas.io.formats.printing import pprint_thing, pprint_thing_encoded
@@ -218,7 +218,7 @@ def return_type(self):
         # clobber types to bool if the op is a boolean operator
         if self.op in (_cmp_ops_syms + _bool_ops_syms):
             return np.bool_
-        return _result_type_many(*(term.type for term in com.flatten(self)))
+        return result_type_many(*(term.type for term in com.flatten(self)))
 
     @property
     def has_invalid_return_type(self) -> bool: