def __init__(self, obj):
"""Accessor for pandas exposed as ``.fr_str``.
fletcher functionality will be used if available otherwise str functions are invoked."""
if not isinstance(obj.values, FletcherBaseArray):
# call StringMethods to validate the input obj
StringMethods(obj)
super().__init__(obj)
def _make_str_accessor(self):
from pandas.core.series import Series
from pandas.core.index import Index
if isinstance(self, Series) and not com.is_object_dtype(self.dtype):
# this really should exclude all series with any non-string values,
# but that isn't practical for performance reasons until we have a
# str dtype (GH 9343)
raise AttributeError("Can only use .str accessor with string "
"values, which use np.object_ dtype in "
"pandas")
elif isinstance(self, Index) and self.inferred_type != 'string':
raise AttributeError("Can only use .str accessor with string "
"values (i.e. inferred_type is 'string')")
return StringMethods(self)
def _make_str_accessor(self):
from pandas.core.series import Series
from pandas.core.index import Index
if isinstance(self, Series) and not com.is_object_dtype(self.dtype):
# this really should exclude all series with any non-string values,
# but that isn't practical for performance reasons until we have a
# str dtype (GH 9343)
raise AttributeError("Can only use .str accessor with string "
"values, which use np.object_ dtype in "
"pandas")
elif isinstance(self, Index):
# see scc/inferrence.pyx which can contain string values
allowed_types = ('string', 'unicode', 'mixed', 'mixed-integer')
if self.inferred_type not in allowed_types:
message = ("Can only use .str accessor with string values "
"(i.e. inferred_type is 'string', 'unicode' or 'mixed')")
raise AttributeError(message)
if self.nlevels > 1:
message = "Can only use .str accessor with Index, not MultiIndex"
raise AttributeError(message)
return StringMethods(self)