utils 0.5

enum

Python doesn’t have a built-in way to define an enum, so this module provides (what I think) is a pretty clean way to go about them.

from utils import enum

class Colors(enum.Enum):
    RED = 0
    GREEN = 1

    # Defining an Enum class allows you to specify a few
    # things about the way it's going to behave.
    class Options:
        frozen = True # can't change attributes
        strict = True # can only compare to itself; i.e., Colors.RED == Animals.COW
                      # will raise an exception.

# or use the enum factory (no Options, though)
ColorsAlso = enum.enum("RED", "GREEN")

Once defined, use is straightforward:

>>> Colors
<class 'blahblah.Colors'>
>>> Colors.RED
<EnumItem: RED [0]>
>>> Colors.RED == 0
True
>>> Colors.RED == Colors.RED
True
>>> Colors.RED = 2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "utils/enum.py", line 114, in __setattr__
    raise TypeError("can't set attributes on a frozen enum")
TypeError: can't set attributes on a frozen enum

math

Currently only has the multiplicative analogue of the built-in sum.

dicts

intersections, differences, winnowing, a few specialized dicts…

lists

flatten and unlisting

bools

currently only provides an xor function.

dates

Mostly cool for the TimePeriod classes:

>>> from datetime import date # will also work with datetimes
>>> time_period = TimePeriod(date(2013, 5, 10), date(2013, 8, 11))
>>> time_period
<TimePeriod: 2013-05-10 00:00:00-2013-08-11 23:59:59>
>>> date(2013, 6, 12) in time_period
True
>>> other_time_period = TimePeriod(date(2013, 6, 1), date(2013, 6, 30))
>>> other_time_period in time_period
True
>>> another_time_period = TimePeriod(date(2013, 8, 1), date(2013, 8, 30))
>>> time_period.overlaps(another_time_period)
True
>>> TimePeriod.get_containing_period(time_period, another_time_period)
<TimePeriod: 2013-05-08 00:00:00-2013-08-30 23:59:59>

and so on and so forth. There’s also a DiscontinousTimePeriod class, which stores a collection of TimePeriods.

There’s also helper functions for common operations like days_ahead and days_ago, which pretty much do what they say on the tin.