满足条件后继续使用更改的参数进行迭代

Question

我需要更改循环外的参数并在满足特定条件后继续迭代。例如，我有披萨列表和字符串列表。我有在满足条件后应该切换的酱汁包列表。如果字符串中存在条件“sauce_error”，我需要从酱包列表中切换到另一个酱包，并使用下一个酱包继续迭代。#list of sauce packssaucePacks = ['sauce_pack1', 'sauce_pack2', 'sauce_pack3', 'sauce_pack4']index = 0saucePack = saucePacks[index]#list of pizzaspizzas = ['pizza1', 'pizza2', 'pizza3_sauce_error', 'pizza4', 'pizza5']#iterating over stringsfor pizza in pizzas:    if 'sauce_error' in pizza:    index = index+1 #need to switch sauce pack if substring in string    print(saucePack, pizza)  else:    print(saucePack, pizza)当“pizza”字符串中出现“sauce_error”时，应将酱包切换到列表中的下一个。期望的输出：sauce_pack1 pizza1sauce_pack1 pizza2sauce_pack2 pizza3_sauce_errorsauce_pack2 pizza4sauce_pack2 pizza5

Answer 1

您只是忘记使用新索引更新您的 saucePack：

#list of sauce packs

saucePacks = ['sauce_pack1', 'sauce_pack2', 'sauce_pack3', 'sauce_pack4']

index = 0

saucePack = saucePacks[index]

#list of pizzas

pizzas = ['pizza1', 'pizza2', 'pizza3_sauce_error', 'pizza4', 'pizza5']

#iterating over strings

for pizza in pizzas:  

    if 'sauce_error' in pizza:

        index = index+1 #need to switch sauce pack if substring in string

        saucePack = saucePacks[index]

        print(saucePack, pizza)

    else:

        print(saucePack, pizza)

Answer 2

使用iteraor会更Pythonic ，而不是更新索引并根据它获取新元素：

#list of sauce packs

saucePacks = iter(['sauce_pack1', 'sauce_pack2', 'sauce_pack3', 'sauce_pack4'])

saucePack = next(saucePacks)

#list of pizzas

pizzas = ['pizza1', 'pizza2', 'pizza3_sauce_error', 'pizza4', 'pizza5']

#iterating over strings

for pizza in pizzas:  

    if 'sauce_error' in pizza:

        saucePack = next(saucePacks)  # takes the next sauce from the list

    print(saucePack, pizza)

请注意，当迭代器耗尽时，您需要小心（您还需要对索引进行处理，以防它超过列表的大小......）

Answer 3

如果该代码对您有意义，请使用它。

#list of sauce packs

saucePacks = ['sauce_pack1', 'sauce_pack2', 'sauce_pack3', 'sauce_pack4']

index = 0

#list of pizzas

pizzas = ['pizza1', 'pizza2', 'pizza3_sauce_error', 'pizza4', 'pizza5']

#iterating over strings

for pizza in pizzas:  

  if 'sauce_error' in pizza:

    index += 1 #need to switch sauce pack if substring in string

    print(saucePacks[index], pizza)

  else:

    print(saucePacks[index], pizza)