Parameters in context manager's __enter__ method?

[skip]

I am working on a file locking class which I'd like to work with Python
2.5's context managers. The acquire method takes an optional timeout
argument:

class FileLock:
...
def acquire(self, timeout=None):
...

def __enter__(self):
self.acquire()
return self

Can that optional timeout be somehow accommodated by the with statement?
(I'm thinking no, which may not be a big shortcoming anyway.)

Thx,

Skip

 

[Matimus]

I am working on a file locking class which I'd like to work with Python
2.5's context managers. The acquire method takes an optional timeout
argument:

class FileLock:
...
def acquire(self, timeout=None):
...

def __enter__(self):
self.acquire()
return self

Can that optional timeout be somehow accommodated by the with statement?
(I'm thinking no, which may not be a big shortcoming anyway.)

Thx,

Skip

I think a better solution might be to create a locking class, and a
seperate context manager class. That way you can pass the timeout as a
parameter to the context managers constructor:

fl = FileLock(...)
with FileLockContext(filelock=fl, timeout=1000):
   # do stuff

But another option along the same line might be to have the acquire
method return the context instance. Then you could write:

class FileLockContext(fl, timeout):
    ...

class FileLock:
    ...
    def acquire(self, timeout=None):
        # do acquiring
        return FileLockContext(self, timeout)

fl = FileLock(...)
with fl.acquire(1000):
  #do stuff

Or, you could go the same path you are already, using a hybrid, and
pass timeout to the FileLock constructor.

Matt