我使用一个while循环来得到结果:

i = 0
while i < len(a)-1:
   result = (a[i]+a[i+1])/2
   print result
   i +=1

对一串数字求和:

sum(list_of_nums)

使用列表推导式生成一个新列表，其中相邻元素在xs中求平均值:

[(x + y) / 2 for x, y in zip(xs, xs[1:])]

将所有相邻元素求和为一个值:

sum((x + y) / 2 for x, y in zip(xs, xs[1:]))

使用成对的itertools食谱:

import itertools
def pairwise(iterable):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    a, b = itertools.tee(iterable)
    next(b, None)
    return itertools.izip(a, b)

def pair_averages(seq):
    return ( (a+b)/2 for a, b in pairwise(seq) )

import numpy as np    
x = [1,2,3,4,5]
[(np.mean((x[i],x[i+1]))) for i in range(len(x)-1)]
# [1.5, 2.5, 3.5, 4.5]

我只使用带有map()的

a = [1,2,3,4,5,6,7,8,9,10]
b = map(lambda x, y: (x+y)/2.0, fib[:-1], fib[1:])
print b

>>> a = range(10)
>>> sum(a)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not callable
>>> del sum
>>> sum(a)
45

sum似乎已经在代码的某个地方定义了，并且覆盖了默认函数。所以我删除了它，问题解决了。