def _set_noconvert_columns(self):
if self.usecols_dtype == 'integer':
# self.usecols is a set, which is documented as unordered
# but in practice, a CPython set of integers is sorted.
# In other implementations this assumption does not hold.
# The following code simulates a different order, which
# before GH 17351 would cause the wrong columns to be
# converted via the parse_dates parameter
self.usecols = list(self.usecols)
self.usecols.reverse()
return CParserWrapper._set_noconvert_columns(self)
def _set_noconvert_columns(self):
if self.usecols_dtype == 'integer':
# self.usecols is a set, which is documented as unordered
# but in practice, a CPython set of integers is sorted.
# In other implementations this assumption does not hold.
# The following code simulates a different order, which
# before GH 17351 would cause the wrong columns to be
# converted via the parse_dates parameter
self.usecols = list(self.usecols)
self.usecols.reverse()
return CParserWrapper._set_noconvert_columns(self)