Set basic stacklevel for SettingWithCopy warning

Author: jtratner

pandas/core/generic.py

@@ -1015,8 +1015,11 @@ def _setitem_copy(self, copy):
  self._is_copy = copy
  return self
 
- def _check_setitem_copy(self):
- """ validate if we are doing a settitem on a chained copy """
+ def _check_setitem_copy(self, stacklevel=4):
+ """ validate if we are doing a settitem on a chained copy.
+
+ If you call this function, be sure to set the stacklevel such that the
+ user will see the error *at the level of setting*"""
  if self._is_copy:
  value = config.get_option('mode.chained_assignment')
 
@@ -1026,7 +1029,7 @@ def _check_setitem_copy(self):
  if value == 'raise':
  raise SettingWithCopyError(t)
  elif value == 'warn':
- warnings.warn(t, SettingWithCopyWarning)
+ warnings.warn(t, SettingWithCopyWarning, stacklevel=stacklevel)
 
  def __delitem__(self, key):
  """