On 07/19/2011 09:43 AM, Ben Finney wrote:
Billy Mays
<81282ed9a88799d21e77957df2d84bd6514d9...@myhashismyemail.com> writes:
I have a method getToken() which checks to see if a value is set, and
if so, return it. However, it doesn't feel pythonic to me:
Clearly that's because the function name is not Pythonic :-)
I'll assume the name is a PEP-8 compatible ‘get_token’.
def getToken(self):
if self.tok:
t = self.tok
self.tok = None
return t
# ...
Are you testing ‘self.tok’ in a boolean context because you don't care
whether it it might be ‘""’ or ‘0’ or ‘0.0’ or ‘[]’ or ‘False’ or lots
of other things that evaluate false in a boolean context?
If you want to test whether it is any value other than ‘None’, that's
not the way to do it. Instead, use ‘if self.token is not None’.
But I don't see why you test it at all, in that case, since you're
immediately setting it to ‘None’ afterward.
Also, the function name is quite misleading; the implication for a
function named ‘get_foo’ is that it is a non-destructive read. I would
expect the name of this function to indicate what's going on much more
explicitly.
My suggestion::
def get_and_reset_token(self):
result = self.token
self.token = None
return result
This function is used in a file parser. There are two methods,
getToken() and peekToken(). getToken pops a token from the file, while
peekToken keeps the token, but still returns it.
Code:
def getToken(self):
if self.tok:
t = self.tok
self.tok = None
return t
try:
t = self.gen.next()
except StopIteration:
return NULL
else:
return t
def peekToken(self):
if not self.tok:
self.tok = self.getToken()
return self.tok
NULL is an enumerated value I have defined above. The idea is for
peekToken to reuse getToken, but to keep the token still around.
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