如何在 Python 中继续嵌套循环

如何在 Python 中使用 continue作为两个嵌套循环的父循环？

for a in b:
for c in d:
for e in f:
if somecondition:
<continue the for a in b loop?>

我知道在大多数情况下可以避免这种情况，但是在 Python 中可以这样做吗？

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小开

You use break to break out of the inner loop and continue with the parent

for a in b:
for c in d:
if somecondition:
break # go back to parent loop
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最佳答案
  1. Break from the inner loop (if there's nothing else after it)
  2. Put the outer loop's body in a function and return from the function
  3. Raise an exception and catch it at the outer level
  4. Set a flag, break from the inner loop and test it at an outer level.
  5. Refactor the code so you no longer have to do this.

I would go with 5 every time.

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Here's a bunch of hacky ways to do it:

  1. Create a local function

    for a in b:
def doWork():
for c in d:
for e in f:
if somecondition:
return # <continue the for a in b loop?>
doWork()

    A better option would be to move doWork somewhere else and pass its state as arguments.

  2. Use an exception

    class StopLookingForThings(Exception): pass


for a in b:
try:
for c in d:
for e in f:
if somecondition:
raise StopLookingForThings()
except StopLookingForThings:
pass
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from itertools import product
for a in b:
for c, e in product(d, f):
if somecondition:
break
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use a boolean flag

problem = False
for a in b:
for c in d:
if problem:
continue
for e in f:
if somecondition:
problem = True
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Looking at All the answers here its all different from how i do it\n Mission:continue to while loop if the if condition is true in nested loop

chars = 'loop|ing'
x,i=10,0
while x>i:
jump = False
for a in chars:
if(a = '|'): jump = True
if(jump==True): continue
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lista = ["hello1", "hello2" , "world"]


for index,word in enumerate(lista):
found = False
for i in range(1,3):
if word == "hello"+str(i):
found = True
break
print(index)
if found == True:
continue
if word == "world":
continue
print(index)

Now what's printed :

>> 1
>> 2
>> 2

This means that the word no.1 ( index = 0 ) appeard first (there's no way for something to be printed before the continue statement). The word no.2 ( index = 1 ) appeared second ( the word "hello1" managed to be printed but not the rest ) and the word no.3 appeard third what mean's that the words "hello1" and "hello2" managed to be printed before the for loop reached this said third word.

To sum up it's just using the found = False / True boolean and the break statement.

Hope it helps!

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#infinite wait till all items obtained
while True:
time.sleep(0.5)
for item in entries:
if self.results.get(item,None) is None:
print(f"waiting for {item} to be obtained")
break #continue outer loop
else:
break
#continue

I wish there could be a labeled loop ...


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