On 10May2012 15:33, Andreas Tawn <andreas.t...@ubisoft.com> wrote:
| Say I've got a class...
|
| class test(object):
| def __init__(self):
| self.foo = 1
| self.bar = 2
| self.baz = 3
|
| I can say...
|
| def __str__(self):
| return "foo: {0}\nbar: {1}\nbaz: {2}".format(self.foo, self.bar, self.baz)
|
| and everything's simple and clean and I can vary the formatting if I need to.
|
| This gets ugly when the class has a lot of attributes because the string
construction gets very long.
This issue bit me once too often a few months ago, and now I have a
class called "O" from which I often subclass instead of from "object".
Its main purpose is a friendly __str__ method, though it also has a
friendly __init__.
Code:
class O(object):
''' A bare object subclass to allow storing arbitrary attributes.
It also has a nicer default str() action, and an aggressive repr().
'''
def __init__(self, **kw):
''' Initialise this O.
Fill in attributes from any keyword arguments if supplied.
This call can be omitted in subclasses if desired.
'''
for k in kw:
setattr(self, k, kw[k])
def __str__(self):
return ( "<%s %s>"
% ( self.__class__.__name__,
",".join([ "%s=%s" % (attr, getattr(self, attr))
for attr in sorted(dir(self)) if
attr[0].isalpha()
])
)
)
So I have some code thus:
from cs.misc import O
......
class FilterModes(O):
def __init__(self, **kw):
# special case one parameter
self._maildb_path = kw.pop('maildb_path')
self._maildb_lock = allocate_lock()
O.__init__(self, **kw)
......
filter_modes = FilterModes(justone=justone,
delay=delay,
no_remove=no_remove,
no_save=no_save,
maildb_path=os.environ['MAILDB'],
maildir_cache={})
This removes a lot of guff from some common procedures.
Hope this helps,
--
Cameron Simpson <c...@zip.com.au> DoD#743
http://www.cskk.ezoshosting.com/cs/
There's a fine line between pathos and pathetic.
- David Stivers s...@stat.rice.edu DoD #857
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