每次在for循环中循环“i”时,如何递增基值? 逻辑是这样的:
fruits = [bananas, apples, pears]
total_fruits_count = 0
for i in fruits:
## some code resolveing fruit count ##
local_fruit_count = 1
total_fruits_count + local_fruit_count
print total_fruits_count
使用此代码,total_fruits_count最终为0.这怎么可能?
答案 0 :(得分:0)
您需要修改total_fruits_count
。
fruits = ["bananas", "apples", "pears"]
total_fruits_count = 0
for i in fruits:
local_fruit_count = 1
total_fruits_count += local_fruit_count
print total_fruits_count
在您的原始代码中,您执行了total_fruits_count + local_fruit_count
,它计算了两者的总和,但没有对它做任何事情。加号等于快捷键+=
会添加值并将其存储在左侧变量total_fruits_count
中。
答案 1 :(得分:0)
这只计算总和并丢弃结果
total_fruits_count + local_fruit_count
您需要=
将结果分配回total_fruits_count
total_fruits_count += local_fruit_count
答案 2 :(得分:0)
我认为您可以根据需要使用枚举函数或len
fruits = ["bananas", "apples", "pears"]
for i, fruit in enumerate(fruits):
print "fruit with index %d is '%s'" % (i, fruit)
total_fruits_count = len(fruits)