def coerce_type(value, datatype):
if isinstance(value, datatype) or value is None:
return value
elif datatype == str:
return str(value)
elif datatype in (int, float):
try:
return datatype(value)
except (TypeError, ValueError):
pass
if isinstance(value, str):
numbers = tuple(extract_numbers(value))
if len(numbers) > 1:
raise ValueError("more than one number found")
elif len(numbers) == 1:
return datatype(numbers[0])
elif isinstance(value, datetime.timedelta):
return datatype(value.total_seconds() / 3600)
elif datatype == datetime.timedelta:
if isinstance(value, (int, float)):
return datetime.timedelta(hours=24 * value)
elif isinstance(value, datetime.time):
return datetime.timedelta(hours=value.hour, minutes=value.minute, seconds=value.second)
elif isinstance(value, datetime.datetime):
return value - EXCEL_START_DATE
def test_extract_number(self):
self.assertEqual(list(extract_numbers('2 people')), [2])
self.assertEqual(list(extract_numbers('1, 2.2, 3., -.4')),
[1, 2.2, 3, -0.4])
self.assertEqual(list(extract_numbers('no numbers')), [])