def _convert_listlike_datetimes(
arg,
format: Optional[str],
name: Label = None,
tz: Optional[Timezone] = None,
unit: Optional[str] = None,
errors: Optional[str] = None,
infer_datetime_format: Optional[bool] = None,
dayfirst: Optional[bool] = None,
yearfirst: Optional[bool] = None,
exact: Optional[bool] = None,
):
"""
Helper function for to_datetime. Performs the conversions of 1D listlike
of dates
Parameters
----------
arg : list, tuple, ndarray, Series, Index
date to be parsed
name : object
None or string for the Index name
tz : object
None or 'utc'
unit : string
None or string of the frequency of the passed data
errors : string
error handing behaviors from to_datetime, 'raise', 'coerce', 'ignore'
infer_datetime_format : boolean
inferring format behavior from to_datetime
dayfirst : boolean
dayfirst parsing behavior from to_datetime
yearfirst : boolean
yearfirst parsing behavior from to_datetime
exact : boolean
exact format matching behavior from to_datetime
Returns
-------
Index-like of parsed dates
"""
if isinstance(arg, (list, tuple)):
arg = np.array(arg, dtype="O")
arg_dtype = getattr(arg, "dtype", None)
# these are shortcutable
if is_datetime64tz_dtype(arg_dtype):
if not isinstance(arg, (DatetimeArray, DatetimeIndex)):
return DatetimeIndex(arg, tz=tz, name=name)
if tz == "utc":
arg = arg.tz_convert(None).tz_localize(tz)
return arg
elif is_datetime64_ns_dtype(arg_dtype):
if not isinstance(arg, (DatetimeArray, DatetimeIndex)):
try:
return DatetimeIndex(arg, tz=tz, name=name)
except ValueError:
pass
elif tz:
# DatetimeArray, DatetimeIndex
return arg.tz_localize(tz)
return arg
elif unit is not None:
if format is not None:
raise ValueError("cannot specify both format and unit")
arg = getattr(arg, "_values", arg)
# GH 30050 pass an ndarray to tslib.array_with_unit_to_datetime
# because it expects an ndarray argument
if isinstance(arg, IntegerArray):
result = arg.astype(f"datetime64[{unit}]")
tz_parsed = None
else:
result, tz_parsed = tslib.array_with_unit_to_datetime(
arg, unit, errors=errors)
if errors == "ignore":
result = Index(result, name=name)
else:
result = DatetimeIndex(result, name=name)
# GH 23758: We may still need to localize the result with tz
# GH 25546: Apply tz_parsed first (from arg), then tz (from caller)
# result will be naive but in UTC
try:
result = result.tz_localize("UTC").tz_convert(tz_parsed)
except AttributeError:
# Regular Index from 'ignore' path
return result
if tz is not None:
if result.tz is None:
result = result.tz_localize(tz)
else:
result = result.tz_convert(tz)
return result
elif getattr(arg, "ndim", 1) > 1:
raise TypeError(
"arg must be a string, datetime, list, tuple, 1-d array, or Series"
)
# warn if passing timedelta64, raise for PeriodDtype
# NB: this must come after unit transformation
orig_arg = arg
try:
arg, _ = maybe_convert_dtype(arg, copy=False)
except TypeError:
if errors == "coerce":
result = np.array(["NaT"], dtype="datetime64[ns]").repeat(len(arg))
return DatetimeIndex(result, name=name)
elif errors == "ignore":
result = Index(arg, name=name)
return result
raise
arg = ensure_object(arg)
require_iso8601 = False
if infer_datetime_format and format is None:
format = _guess_datetime_format_for_array(arg, dayfirst=dayfirst)
if format is not None:
# There is a special fast-path for iso8601 formatted
# datetime strings, so in those cases don't use the inferred
# format because this path makes process slower in this
# special case
format_is_iso8601 = format_is_iso(format)
if format_is_iso8601:
require_iso8601 = not infer_datetime_format
format = None
tz_parsed = None
result = None
if format is not None:
try:
# shortcut formatting here
if format == "%Y%m%d":
try:
# pass orig_arg as float-dtype may have been converted to
# datetime64[ns]
orig_arg = ensure_object(orig_arg)
result = _attempt_YYYYMMDD(orig_arg, errors=errors)
except (ValueError, TypeError, OutOfBoundsDatetime) as err:
raise ValueError(
"cannot convert the input to '%Y%m%d' date format"
) from err
# fallback
if result is None:
try:
result, timezones = array_strptime(arg,
format,
exact=exact,
errors=errors)
if "%Z" in format or "%z" in format:
return _return_parsed_timezone_results(
result, timezones, tz, name)
except OutOfBoundsDatetime:
if errors == "raise":
raise
elif errors == "coerce":
result = np.empty(arg.shape, dtype="M8[ns]")
iresult = result.view("i8")
iresult.fill(iNaT)
else:
result = arg
except ValueError:
# if format was inferred, try falling back
# to array_to_datetime - terminate here
# for specified formats
if not infer_datetime_format:
if errors == "raise":
raise
elif errors == "coerce":
result = np.empty(arg.shape, dtype="M8[ns]")
iresult = result.view("i8")
iresult.fill(iNaT)
else:
result = arg
except ValueError as e:
# Fallback to try to convert datetime objects if timezone-aware
# datetime objects are found without passing `utc=True`
try:
values, tz = conversion.datetime_to_datetime64(arg)
dta = DatetimeArray(values, dtype=tz_to_dtype(tz))
return DatetimeIndex._simple_new(dta, name=name)
except (ValueError, TypeError):
raise e
if result is None:
assert format is None or infer_datetime_format
utc = tz == "utc"
result, tz_parsed = objects_to_datetime64ns(
arg,
dayfirst=dayfirst,
yearfirst=yearfirst,
utc=utc,
errors=errors,
require_iso8601=require_iso8601,
allow_object=True,
)
if tz_parsed is not None:
# We can take a shortcut since the datetime64 numpy array
# is in UTC
dta = DatetimeArray(result, dtype=tz_to_dtype(tz_parsed))
return DatetimeIndex._simple_new(dta, name=name)
utc = tz == "utc"
return _box_as_indexlike(result, utc=utc, name=name)
def _convert_listlike_datetimes(
arg,
format: str | None,
name: Hashable = None,
tz: Timezone | None = None,
unit: str | None = None,
errors: str = "raise",
infer_datetime_format: bool = False,
dayfirst: bool | None = None,
yearfirst: bool | None = None,
exact: bool = True,
):
"""
Helper function for to_datetime. Performs the conversions of 1D listlike
of dates
Parameters
----------
arg : list, tuple, ndarray, Series, Index
date to be parsed
name : object
None or string for the Index name
tz : object
None or 'utc'
unit : str
None or string of the frequency of the passed data
errors : str
error handing behaviors from to_datetime, 'raise', 'coerce', 'ignore'
infer_datetime_format : bool, default False
inferring format behavior from to_datetime
dayfirst : bool
dayfirst parsing behavior from to_datetime
yearfirst : bool
yearfirst parsing behavior from to_datetime
exact : bool, default True
exact format matching behavior from to_datetime
Returns
-------
Index-like of parsed dates
"""
if isinstance(arg, (list, tuple)):
arg = np.array(arg, dtype="O")
arg_dtype = getattr(arg, "dtype", None)
# these are shortcutable
if is_datetime64tz_dtype(arg_dtype):
if not isinstance(arg, (DatetimeArray, DatetimeIndex)):
return DatetimeIndex(arg, tz=tz, name=name)
if tz == "utc":
arg = arg.tz_convert(None).tz_localize(tz)
return arg
elif is_datetime64_ns_dtype(arg_dtype):
if not isinstance(arg, (DatetimeArray, DatetimeIndex)):
try:
return DatetimeIndex(arg, tz=tz, name=name)
except ValueError:
pass
elif tz:
# DatetimeArray, DatetimeIndex
return arg.tz_localize(tz)
return arg
elif unit is not None:
if format is not None:
raise ValueError("cannot specify both format and unit")
return _to_datetime_with_unit(arg, unit, name, tz, errors)
elif getattr(arg, "ndim", 1) > 1:
raise TypeError(
"arg must be a string, datetime, list, tuple, 1-d array, or Series"
)
# warn if passing timedelta64, raise for PeriodDtype
# NB: this must come after unit transformation
orig_arg = arg
try:
arg, _ = maybe_convert_dtype(arg, copy=False)
except TypeError:
if errors == "coerce":
npvalues = np.array(["NaT"],
dtype="datetime64[ns]").repeat(len(arg))
return DatetimeIndex(npvalues, name=name)
elif errors == "ignore":
idx = Index(arg, name=name)
return idx
raise
arg = ensure_object(arg)
require_iso8601 = False
if infer_datetime_format and format is None:
format = _guess_datetime_format_for_array(arg, dayfirst=dayfirst)
if format is not None:
# There is a special fast-path for iso8601 formatted
# datetime strings, so in those cases don't use the inferred
# format because this path makes process slower in this
# special case
format_is_iso8601 = format_is_iso(format)
if format_is_iso8601:
require_iso8601 = not infer_datetime_format
format = None
if format is not None:
res = _to_datetime_with_format(arg, orig_arg, name, tz, format, exact,
errors, infer_datetime_format)
if res is not None:
return res
assert format is None or infer_datetime_format
utc = tz == "utc"
result, tz_parsed = objects_to_datetime64ns(
arg,
dayfirst=dayfirst,
yearfirst=yearfirst,
utc=utc,
errors=errors,
require_iso8601=require_iso8601,
allow_object=True,
)
if tz_parsed is not None:
# We can take a shortcut since the datetime64 numpy array
# is in UTC
dta = DatetimeArray(result, dtype=tz_to_dtype(tz_parsed))
return DatetimeIndex._simple_new(dta, name=name)
utc = tz == "utc"
return _box_as_indexlike(result, utc=utc, name=name)
def test_is_iso_format(fmt, expected):
# see gh-41047
result = parsing.format_is_iso(fmt)
assert result == expected
