大家好，我在尝试对列表中的所有值求和时遇到问题。我不确定这是否真的可行。
dL= list(csv.reader(input))
sL = dL [14247:14611]
a = [row[5] for row in sL[1:]]
print a
这段代码是我目前所拥有的并产生了结果
['5.0', '0.0', '0.0', '0.0', '0.0', '1.6', '4.4', '14.0', '0.0', '0.0', '0.8', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '95.6', '63.6', '0.0', '0.0', '0.0', '9.0', '0.0', '0.0', '0.0', '0.0', '20.2', '14.4', '1.6', '0.0', '7.6', '2.4', '0.0', '11.4', '0.0', '79.4', '60.4', '27.2', '', '1.8', '0.0', '0.0', '29.6', '67.6', '2.2', '0.0', '0.0', '0.0', '14.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '', '3.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '6.2', '0.0', '0.0', '0.0', '0.8', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.2', '11.8', '2.4', '0.0', '0.0', '0.0', '0.4', '16.8', '8.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '2.6', '27.2', '77.0', '0.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '9.2', '2.6', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '1.6', '0.0', '0.0', '0.0', '0.0', '0.0', '6.8', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '', '', '', '', '', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '37.8', '0.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0']
上面的列表不是键入的，而是由函数代码生成的。这会影响结果吗？
任何人都可以帮助我向我展示如何解决此问题并将所有这些值汇总到此列表的代码中。我相信我必须加入字符串才能这样做，但我不确定。您能告诉我是否可以对列表的所有这些值求和吗？如果可以，我该怎么做？
编辑:
THANKS FOR ALL THE HELP GUYS
请您参考如下方法:
我会使用 math.fsum 来获得更准确的总和:
>>> nums = ['5.0', '0.0', '0.0', '0.0', '0.0', '1.6', '4.4', '14.0', '0.0', '0.0', '0.8', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '95.6', '63.6', '0.0', '0.0', '0.0', '9.0', '0.0', '0.0', '0.0', '0.0', '20.2', '14.4', '1.6', '0.0', '7.6', '2.4', '0.0', '11.4', '0.0', '79.4', '60.4', '27.2', '', '1.8', '0.0', '0.0', '29.6', '67.6', '2.2', '0.0', '0.0', '0.0', '14.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '', '3.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '6.2', '0.0', '0.0', '0.0', '0.8', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.2', '11.8', '2.4', '0.0', '0.0', '0.0', '0.4', '16.8', '8.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '2.6', '27.2', '77.0', '0.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '9.2', '2.6', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '0.2', '0.0', '0.0', '0.0', '0.0', '1.6', '0.0', '0.0', '0.0', '0.0', '0.0', '6.8', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '', '', '', '', '', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '37.8', '0.2', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0', '0.0']
>>> from math import fsum
>>> fsum(float(n or 0.0) for n in nums)
749.8
相对于
>>> sum(float(n or 0.0) for n in nums)
749.8000000000003
使用您的代码，一种更有效的方法，无需立即将整个文件保存到内存中:
from itertools import islice
dL= csv.reader(input)
sL = islice(dL, 14247+1, 14611)
a = [row[5] for row in sL]
print fsum(float(n or 0.0) for n in a)
