stackoverflow.com › questions › 6346492 › how-to-stop-one-or-multiple-for-loops

Use break and continue to do this. Breaking nested loops can be done in Python using the following:

for a in range(...):
   for b in range(..):
      if some condition:
         # break the inner loop
         break
   else:
      # will be called if the previous loop did not end with a `break` 
      continue
   # but here we end up right after breaking the inner loop, so we can
   # simply break the outer loop as well
   break

Another way is to wrap everything in a function and use return to escape from the loop.

Answer from Alexander Gessler on Stack Overflow

Stack Overflow

stackoverflow.com › questions › 6346492 › how-to-stop-one-or-multiple-for-loops

python - How to stop one or multiple for loop(s) - Stack Overflow

The simple Way: a sentinel variable

n = L[0][0]
m = len(A)
found = False
for i in range(m):
   if found:
      break
   for j in range(m):
     if L[i][j] != n: 
       found = True
       break

Pros: easy to understand Cons: additional conditional statement for every loop

The hacky Way: raising an exception

n = L[0][0]
m = len(A)

try:
  for x in range(3):
    for z in range(3):
     if L[i][j] != n: 
       raise StopIteration
except StopIteration:
   pass

Pros: very straightforward Cons: you use Exception outside of their semantic

The clean Way: make a function

def is_different_value(l, elem, size):
  for x in range(size):
    for z in range(size):
     if l[i][j] != elem: 
       return True
  return False
   
if is_different_value(L, L[0][0], len(A)):
  print "Doh"

pros: much cleaner and still efficient cons: yet feels like C

The pythonic way: use iteration as it should be

def is_different_value(iterable):
  first = iterable[0][0]
  for l in iterable:
    for elem in l:
       if elem != first: 
          return True
  return False
   
if is_different_value(L):
  print "Doh"

pros: still clean and efficient cons: you reinvdent the wheel

The guru way: use `any()`:

def is_different_value(iterable):
  first = iterable[0][0]
  return any(cell != first for col in iterable for cell in col)

if is_different_value(L):
  print "Doh"

pros: you'll feel empowered with dark powers cons: people that will read you code may start to dislike you

DigitalOcean

digitalocean.com › community › tutorials › how-to-use-break-continue-and-pass-statements-when-working-with-loops-in-python-3

How to Break Out of Multiple Loops in Python | DigitalOcean

August 7, 2025 - For instance, you might encounter ... placeholder for future code. Python provides three powerful statements to handle these cases: break, continue, and pass. The break statement allows you to exit a loop entirely when a specific condition is met, effectively stopping the loop ...

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