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ophelia / ophelia / util.txt

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=================
Ophelia utilities
=================

Namespaces
==========

Handling a request involves namespaces for a number of things, e.g. for the
page template context, or the request environment variables. This need is in
principle served by plain Python dictionaries. However, it sometimes feels
more convenient and natural to access a particular namespace member as an
object attribute rather than by a key reference. Namespaces are Python
dictionaries which expose their values as attributes:

>>> from ophelia.util import Namespace
>>> Namespace()
{}
>>> ns = Namespace(foo="bar")
>>> ns
{'foo': 'bar'}
>>> ns["foo"]
'bar'
>>> ns.foo
'bar'
>>> ns.foo = "baz"
>>> ns["foo"]
'baz'
>>> ns["asdf"] = "fdsa"
>>> ns.asdf
'fdsa'

Dictionary methods work as expected, e.g. update():

>>> a = Namespace()
>>> a.foo = 1
>>> b = Namespace()
>>> b.bar = 2
>>> a.update(b)
>>> a.bar
2


Unicode dates and times
=======================

Ophelia provides its own version of strftime which always returns unicode.
It works the same as the time.strftime function otherwise. With only a format
string given, it formats the current time:

>>> from ophelia.util import strftime
>>> strftime("%c")
u'...'

Our strftime function uses the current locale's encoding to decode
time.strftime's output, as that is what time.strftime uses to encode it in the
first place. We'd like to try it out but we cannot be sure of the availability
of any particular interesting locale. Therefore we use a boring one to
demonstrate the call at all:

>>> import locale
>>> locale.setlocale(locale.LC_ALL, "C")
'C'
>>> import datetime
>>> strftime("%B", datetime.date(2007, 3, 1))
u'March'

Not only do we always get unicode output from our strftime function, but we
can also pass it a unicode format string (which time.strftime would not
accept):

>>> strftime(u"The third month is named %B...", datetime.date(2007, 3, 1))
u'The third month is named March...'

However, to avoid confusion with the locale's encoding which we don't even
want to think about when calling strftime, we cannot pass any encoded strings
as the format specification:

>>> strftime("Im sch\xf6nen Monat %B...", datetime.date(2007, 3, 1))
Traceback (most recent call last):
UnicodeDecodeError: 'ascii' codec can't decode byte ... in position ...


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