Question

我有一个for循环，我正在寻找一种只要满足该条件就跳过几次迭代的方法。我该如何在python中做到这一点？

这是第一次满足条件的示例，

for i in range(0, 200000):
    # (when 0 % 300 it meets this criteria) 
    if (i % 300) == 0:             
        # whenever this condition is met skip 4 iterations forward
        # now skip 4 iterations --- > (0, 1, 2, 3)

    # now continue from 4th iteration until the condition is met again

类似地，只要满足条件，就应该发生这种情况。

Answer 1

在每个满足条件（(i % 300) == 0）之后跳4个步骤等于跳过0，1，2和3。您只需更改条件即可使用(i % 300) < 4跳过所有这些步骤。

for i in range(0, 200000):
    # (when 0 % 300 it meets this criteria) 
    if (i % 300) < 4: # Skips iteration when remainder satisfier condition            
    #if (i % 300) in (0,1,2,3): # or alternative skip condition
        # whenever this condition is met skip 4 iterations forward
        # now skip 4 iterations --- > (0, 1, 2, 3)
        continue

    # now continue from 4th iteration 
    print(i)

Answer 2

您可以将迭代器（range）保存在变量中，并在需要时在其上调用next(it)。请注意，这将丢弃这些值。

# Note that we call iter to get an iterator. `range` is an iterable
# that returns another iterator so that it can be used multiple
# times in a for loop.
it = iter(range(200000))

for i in it:
    if not i%300:
        for _ in range(4): # 4 is the amount of values to skip
            i = next(it)   # Update `i` for use later on

    # `i` will never be a multiple of 300; it is updated above
    ...

如何基于if条件跳过for循环中的一些迭代？

2 个答案: