def discover_typeengine(typ):
if isinstance(typ, sa.Interval):
if typ.second_precision is None and typ.day_precision is None:
return datashape.TimeDelta(unit='us')
elif typ.second_precision == 0 and typ.day_precision == 0:
return datashape.TimeDelta(unit='s')
if typ.second_precision in units_of_power and not typ.day_precision:
units = units_of_power[typ.second_precision]
elif typ.day_precision > 0:
units = 'D'
else:
raise ValueError('Cannot infer INTERVAL type with parameters'
'second_precision=%d, day_precision=%d' %
(typ.second_precision, typ.day_precision))
return datashape.TimeDelta(unit=units)
if typ in revtypes:
return dshape(revtypes[typ])[0]
if type(typ) in revtypes:
return revtypes[type(typ)]
if isinstance(typ, (sa.NUMERIC, sa.DECIMAL)):
return datashape.Decimal(precision=typ.precision, scale=typ.scale)
if isinstance(typ, (sa.String, sa.Unicode)):
return datashape.String(typ.length, 'U8')
else:
for k, v in revtypes.items():
if isinstance(k, type) and (isinstance(typ, k) or hasattr(
typ, 'impl') and isinstance(typ.impl, k)):
return v
if k == typ:
return v
raise NotImplementedError("No SQL-datashape match for type %s" % typ)
def test_timedelta_sql_discovery_hour_minute(freq):
# these always compare equal to a seconds timedelta, because no data loss
# will occur with this heuristic. this implies that the sa.Table was
# constructed with day_precision == 0 and second_precision == 0
ds = '{name: string, amount: int, duration: timedelta[unit="%s"]}' % freq
t = dshape_to_table('td_bank', ds)
assert discover(t).measure['duration'] == datashape.TimeDelta('s')
def test_get_numba_type():
assert get_numba_type(datashape.bool_) == nb.bool_
assert get_numba_type(datashape.date_) == datetime64('D')
assert get_numba_type(datashape.datetime_) == datetime64('us')
assert get_numba_type(datashape.timedelta_) == timedelta64('us')
assert get_numba_type(datashape.TimeDelta('D')) == timedelta64('D')
assert get_numba_type(datashape.int64) == int64
assert get_numba_type(datashape.String(7, "A")) == char(7)
assert get_numba_type(datashape.String(None, "A")) == nb.types.string
assert get_numba_type(datashape.String(7)) == unichar(7)
def test_timedelta_sql_discovery(freq):
ds = '{name: string, amount: int, duration: timedelta[unit="%s"]}' % freq
t = dshape_to_table('td_bank', ds)
assert discover(t).measure['duration'] == datashape.TimeDelta(freq)
