kj wrote:
I'm trying to subclass file, overriding the readline method. The
new method definition begins with
def readline(self, size=None):
line = self.file.readline(size)
# etc., etc.
...where the self.file attribute is a regular file object.
This works fine if I invoke the new method with an integer argument,
but if I invoke it without arguments, I get the error
TypeError: an integer is required
...which I suppose comes from the call to self.file.readline(None).
I know that I could rewrite the method like this:
def readline(self, size=None):
if size == None:
line = self.file.readline()
else:
line = self.file.readline(size)
# etc., etc.
...but this seems to me exceptionally awkward. (Actually, it's worse
than awkward: it fails to complain when the overriding method is
called with the argument None. It would be better to test for the
number of arguments passed to the function, but I can't figure out
how to do this either.)
Is there a better idiom?
Since the manual implies that negative values have no effect, try this:
def readline(self, size=-1):
line = self.file.readline(size)
# etc., etc.
I tested this (just barely), and it seems to work as you wish.
Gary Herron
TIA!
Kynn
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