While it is true that sorted(iterable) is essentially
def sorted(iterable):
tem = list(iterable)
tem.sort
return tem
the body is not an expression and cannot be substituted in an
expression. The need for the short form was thought common enough to be
worth, *on balance*, a new builtin name. It is not surprising that not
all agree.
Reversed(iterable) is more complicated because it returns an iterator,
not a list, and looks for a class-specific __reversed__ method. I think
it is more or less equivalent to the following:
def _rev_iter(seq, n):
for i in range(n-1, -1, -1):
# many people have trouble getting the range right
yield seq[i]
def reversed(iterable):
try:
return iterable.__reversed__()
except AttributeError:
try:
itlen = iterable.__len__
iterable.__getitem__
return _rev_iter(iterable, itlen)
except AttributeError:
raise TypeError("argument to reversed() must be a sequence")
Even if list mutation methods returned the list, which they do not and
for good reason, reversed(it) is not the same as list(it).reverse(). So
that part of the premise of this thread is wrong.
--
Terry Jan Reedy
--
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