Hello everyone,
Disclaimer: I'm doing this mainly for learning purposes, to feel what
it's good for.
I'm trying to get print_internal_date become a static method AND to
refer to it in a class attribute 'tagdata' dict.
class PYFileInfo(FileInfo):
'python file properties'
@staticmethod
def print_internal_date(filename):
f = open(filename + 'c', "rb")
data = f.read(8)
mtime = struct.unpack("<i", data[4:])
return time.asctime(time.gmtime(mtime[0]))
tagdata = {'compiled_fname': lambda x: x + 'c',
'size': os.path.getsize,
'internal_date': print_internal_date
}
def __init__(self, fname=None):
FileInfo.__init__(self,fname)
def __setitem__(self, key, value):
FileInfo.__setitem__(self, key, value)
if key == 'name' and value:
self.__get_props(value)
def __get_props(self, value):
py_compile.compile(value)
for tag, fun in PYFileInfo.tagdata.items():
self[tag] = fun(value)
But:
c:/Python26/pythonw.exe -u "C:/mp3i/finfo2.py"
Traceback (most recent call last):
File "C:/mp3i/finfo2.py", line 100, in <module>
insts = list_dir(r'c:\mp3i',['.mp3', '.py'])
File "C:/mp3i/finfo2.py", line 93, in list_dir
insts = [c(f) for c,f in class_files]
File "C:/mp3i/finfo2.py", line 69, in __init__
FileInfo.__init__(self,fname)
File "C:/mp3i/finfo2.py", line 12, in __init__
self['name'] = filename
File "C:/mp3i/finfo2.py", line 74, in __setitem__
self.__get_props(value)
File "C:/mp3i/finfo2.py", line 79, in __get_props
self[tag] = fun(value)
TypeError: 'staticmethod' object is not callable
I think I know where the problem is: what resides in tagdata is a static
method 'wrapper', not the function itself, according to:
http://docs.python.org/reference/datamodel.html
"Static method objects
Static method objects provide a way of defeating the transformation
of function objects to method objects described above. A static method
object is a wrapper around any other object, usually a user-defined
method object. When a static method object is retrieved from a class or
a class instance, the object actually returned is the wrapped object,
which is not subject to any further transformation. Static method
objects are not themselves callable, although the objects they wrap
usually are."
So, how do I get out the wrapped function out of static method without
class call or instance call? (to be called in self[tag] = fun(value))
Yes, I do know that if I just get rid of @staticmethod, this works
without a hitch.
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