range() and xrange()

# python2
>>> a = range(5)
>>> a
[0, 1, 2, 3, 4]
>>> b = xrange(5)
>>> b
xrange(5)

但在python3中，Python3中只有range()。

# python3
>>> a = range(5)
>>> a
range(0, 5)
>>> b = xrange(5)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'xrange' is not