On Aug 11, 3:42 pm, Duncan Booth <duncan.bo...@invalid.invalid> wrote: > Terry <terry.yin...@gmail.com> wrote: > > I'm trying to implement something like: > > > remote_map(fun, list) > > > to execute the function on a remove machine. But the problem is I > > cannot pickle a lambda function and send it to the remote machine. > > > Is there any possible way to pickle (or other method) any functions > > including lambda? > > You can pickle any named functions that are declared at module scope. > > You cannot pickle anonymous functions, methods, or functions declared > nested inside other functions. The function must be present in the same > module when you unpickle it, and if the definition has changed between > pickling and unpickling the new definition will be used (just as other > instances will use the current class definition not the one they were > pickled with). > > You probably could pickle some of the components needed to create your > lambda and construct a new function from it when unpickling: try the code > object, the name of the module to be used for the globals, and default > arguments. I don't think you can pickle the closure so better make sure > your lambda doesn't need one, and be very careful to ensure that you > restore the pickle in the same version of Python otherwise the code object > might break. Best just avoid this and use named functions for anything that > needs pickling. > > -- > Duncan Boothhttp://kupuguy.blogspot.com
Yes, I'm think of pickle (actually marshal) the code object. Otherwise I have to use string and eval:-( The reason I need to be able to pickle any function is because I want my remote machine knows nothing about the function before receiving it, so I don't need to update the source code in the remote machine very often. br, terry -- http://mail.python.org/mailman/listinfo/python-list
