Arithmetic sequences in Python

[Paul Rubin]

Tom Anderson <twic at urchin.earth.li> writes:
> > listx/dictx/setx would be the display forms as well as the constructor forms.
> 
> Could these even replace the current forms? If you want the equivalent
> of list(sometuple), write list(*sometuple). 

The current list function is supposed to be something like a typecast:

list() = []
xlist() = []   # ok

list(list()) = []   # casting a list to a list does nothing
xlist(xlist()) = [[]]  # make a new list, not the same

list(xrange(4)) = [0,1,2,3]
xlist(xrange(4)) = [xrange(4)]   # not the same

list((1,2)) = [1,2]
xlist((1,2)) = [(1,2)]

etc.