Python技巧(enumerate)

>>> i = 0>>> seq = ['one', 'two', 'three']>>> for element in seq:...     seq[i] = '%d: %s' % (i, seq[i])...     i += 1...>>> seq['0: one', '1: two', '2: three']>>> seq = ['one', 'two', 'three']>>> for i, element in enumerate(seq):...     seq[i] = '%d: %s' % (i, seq[i])...>>> seq['0: one', '1: two', '2: three']>>> def _treatment(pos, element):...     return '%d: %s' %(pos, element)...>>> seq = ['one', 'two', 'three']>>> [_treatment(i, e1) for i, e1 in enumerate(seq)]['0: one', '1: two', '2: three']

最后一种方式更容易矢量化，因为它共享了基于序列中单个项目的小函数。
每当要对序列中的内容进行循环处理时，就应该尝试用List comprehensions来代替它。