Tools

Deprecated since version 0.6.2.

Some useful tools for use with Norman are provided in norman.tools.

norman.tools.dtfromiso(iso)

Return a datetime object from a string representation in ISO format.

The database serialisation procedures store datetime objects as strings, in ISO format. This provides an easy way to reverse this. datetime, date and time objects are all supported.

Note that this assumes naive datetimes.

>>> import datetime
>>> dt = datetime.date(2001, 12, 23)
>>> isodt = str(dt)
>>> dtfromiso(isodt)
datetime.date(2001, 12, 23)

norman.tools.float2(s[, default=0.0])

Convert s to a float, returning default if it cannot be converted.

>>> float2('33.4', 42.5)
33.4
>>> float2('cannot convert this', 42.5)
42.5
>>> float2(None, 0)
0
>>> print(float2('default does not have to be a float', None))
None

norman.tools.int2(s[, default=0])

Convert s to an int, returning default if it cannot be converted.

>>> int2('33', 42)
33
>>> int2('cannot convert this', 42)
42
>>> print(int2('default does not have to be an int', None))
None

norman.tools.reduce2(func, seq, default)

Similar to functools.reduce, but return default if seq is empty.

The third argument to functools.reduce is an initializer, which essentially acts as the first item in seq. In this function, default is returned if seq is empty, otherwise it is ignored.

>>> reduce2(lambda a, b: a + b, [1, 2, 3], 4)
6
>>> reduce2(lambda a, b: a + b, [], 'default')
'default'