skyworld writes: > Hi, > > I see someone's code as this: > > class ABC: .... > def __init__(self, env): > ....... > self.jmpTable['batchQ']['submit_job'] = self.lsf_submit > ....... > def lsf_submit(self, cmd,env): > ..... > > what confused me is why there is no parentheses for self.lsf_submit in > "self.jmpTable['batchQ']['submit_job'] = self.lsf_submit"? what does > this piece of code mean? thanks.
Functions are objects. The above is storing the function lsf_submit in a dict from where it can later be taken and invoked. The invocation is indicated by the parentheses after an expression that denotes a function. Consider the following, and play with examples of your own in a Python interpreter. >>> from math import acos >>> def foo(x): return acos, x ... >>> foo(-1) (<built-in function acos>, -1) >>> foo(-1)[0] <built-in function acos> >>> foo(-1)[0](foo(-1)[1]) 3.141592653589793 Or simply: >>> acos <built-in function acos> >>> acos(-1) 3.141592653589793 -- http://mail.python.org/mailman/listinfo/python-list
