蟒蛇.如何总结列表中的所有偶数？

Question

我对这个主题完全不熟悉,我想问一下如何在列表中总结所有甚至整数(不使用函数(我还没有研究它们))？例如:

myList = [1, 3, 5, 6, 8, 10, 34, 2, 0, 3]

我创建for循环

for i in myList:
  if x % 2 ==0:
  # I'm stuck here

如何存储这些值来计算总和？

Answer 1

使用生成器表达式:

>>> myList = [1, 3, 5, 6, 8, 10, 34, 2, 0, 3]
>>> sum(num for num in myList if not num%2)
60

使用filter():

>>> myList = [1, 3, 5, 6, 8, 10, 34, 2, 0, 3]
>>> sum(filter(lambda x: not x%2, myList))
60

使用手动循环:

>>> myList = [1, 3, 5, 6, 8, 10, 34, 2, 0, 3]
>>> result = 0
>>> for item in myList:
...     if not item%2:
...             result += item
...
>>> result
60

Answer 2

对不起,我只是打高尔夫了.也许它会教某人〜操作员.

>>> myList = [1, 3, 5, 6, 8, 10, 34, 2, 0, 3]
>>> sum(~i%2*i for i in myList)
60

找到另一个长度相同的:

>>> sum(i&~i%-2for i in myList)
60