def reverse(spam):
    k = []
    for i in spam:
        k.insert(0,i)
    return "".join(k)

使用list.reverse()，然后像往常一样迭代。

http://docs.python.org/tutorial/datastructures.html

反向函数在这里很方便:

myArray = [1,2,3,4]
myArray.reverse()
for x in myArray:
    print x

>>> l = ["a","b","c","d"]
>>> l.reverse()
>>> l
['d', 'c', 'b', 'a']

OR

>>> print l[::-1]
['d', 'c', 'b', 'a']

其他答案都不错，但如果你想这么做 列表理解风格

collection = ['a','b','c']
[item for item in reversed( collection ) ]

此外，您可以使用“range”或“count”函数。 如下:

a = ["foo", "bar", "baz"]
for i in range(len(a)-1, -1, -1):
    print(i, a[i])

3 baz
2 bar
1 foo

你也可以使用itertools中的"count"，如下所示:

a = ["foo", "bar", "baz"]
from itertools import count, takewhile

def larger_than_0(x):
    return x > 0

for x in takewhile(larger_than_0, count(3, -1)):
    print(x, a[x-1])

3 baz
2 bar
1 foo