code: def fill_binop(left, right, fill_value):
      """
      If a non-None fill_value is given, replace null entries in left and right
      with this value, but only in positions where _one_ of left/right is null,
      not both.
  
      Parameters
      ----------
      left : array-like
      right : array-like
      fill_value : object
  
      Returns
      -------
      left : array-like
      right : array-like
  
      Notes
      -----
      Makes copies if fill_value is not None and NAs are present.
      """
      if fill_value is not None:
          left_mask = isna(left)
          right_mask = isna(right)
  
          # one but not both
          mask = left_mask ^ right_mask
  
          if left_mask.any():
              # Avoid making a copy if we can
              left = left.copy()
              left[left_mask & mask] = fill_value
  
          if right_mask.any():
              # Avoid making a copy if we can
              right = right.copy()
              right[right_mask & mask] = fill_value
  
      return left, right
  
imports: from __future__ import annotations
  import datetime
  from functools import partial
  import operator
  from typing import TYPE_CHECKING, Any
  import warnings
  import numpy
  from pandas._libs import NaT, Timedelta, Timestamp, lib, ops
  from pandas._libs.tslibs import BaseOffset, get_supported_dtype, is_supported_dtype, is_unitless
  from pandas.util._exceptions import find_stack_level
  from pandas.core.dtypes.cast import construct_1d_object_array_from_listlike, find_common_type
  from pandas.core.dtypes.common import ensure_object, is_bool_dtype, is_list_like, is_numeric_v_string_like, is_object_dtype, is_scalar
  from pandas.core.dtypes.generic import ABCExtensionArray, ABCIndex, ABCSeries
  from pandas.core.dtypes.missing import isna, notna
  from pandas.core import roperator
  from pandas.core.computation import expressions
  from pandas.core.construction import ensure_wrapped_if_datetimelike
  from pandas.core.ops import missing
  from pandas.core.ops.dispatch import should_extension_dispatch
  from pandas.core.ops.invalid import invalid_comparison
label_desc: Use image node_id 1 for calling a global function with example usage: fill_binop(left, right, fill_value) and returns: left,  right