【Kata Daily 190927】Counting sheep...（数绵羊）

题目：

Consider an array of sheep where some sheep may be missing from their place. We need a function that counts the number of sheep present in the array (true means present).

For example,

[True,  True,  True,  False,
  True,  True,  True,  True ,
  True,  False, True,  False,
  True,  False, False, True ,
  True,  True,  True,  True ,
  False, False, True,  True]

The correct answer would be 17.

Hint: Don't forget to check for bad values like null/undefined

解题办法：

def count_sheeps(arrayOfSheeps):
    sum = 0
    for x in arrayOfSheeps:
      if x:
          sum += 1
    return sum

其他解法：

def count_sheeps(arrayOfSheeps):
  return arrayOfSheeps.count(True)

知识点：

1、计算s数量可以使用l.count(s)