Brian Elmegaard wrote: ... > The code that runs: > > class Foo: > def __init__(self,x): > self.x=x > > y=[] > y.append(Foo(10.0)) > y.append(Foo(110.0)) > y.append(Foo(60.0)) > > ys=[] > y_max=0.0 > y_min=0.0 > > for s in y: > ys.extend([s.x]) > y_max=max(s.x,y_max) > y_min=min(s.x,y_min) > > yz=[] > for i in range(len(ys)-1): > yz.append(ys[i+1]-ys[i]) > > What I hoped I could do: ... > yz=[y[:-1].x-y[1:].x]
Based on the code that runs, you want* this: [(y[x+1].x-y[x].x) for x in range(len(y)-1) ] FWIW, "-" does not work across lists. You could use map if you wanted, but personally I prefer the explicit loop which you wanted to not use: > yz=[] > for i in range(len(ys)-1): > yz.append(ys[i+1]-ys[i]) Since personally I find that a lot clearer than: map(float.__sub__, [X.x for X in y[1:]], [X.x for X in y[:-1] ]) Regards, Michael. -- http://mail.python.org/mailman/listinfo/python-list
