while True:
    try:
        # stuff
        stuff_1()
        if some_cond:
            continue
        if other_cond:
            break
        stuff_2()
    finally:
        # condition
        if not condition:
            break

[x]条件只检查后运行的东西 [x]不是函数调用 [x]条件不是函数调用 [x]的东西可以包含流量控制 []避免检查条件，如果东西叫break(可以用另一个布尔值)

我不知道你想干什么。你可以像这样实现一个do-while循环:

while True:
  stuff()
  if fail_condition:
    break

Or:

stuff()
while not fail_condition:
  stuff()

你为什么要用一个do while循环来打印列表中的东西?为什么不直接使用:

for i in l:
  print i
print "done"

更新:

你有台词清单吗?你想一直遍历它吗?如何:

for s in l: 
  while True: 
    stuff() 
    # use a "break" instead of s = i.next()

这看起来像是你想要的吗?对于您的代码示例，它将是:

for s in some_list:
  while True:
    if state is STATE_CODE:
      if "//" in s:
        tokens.add( TOKEN_COMMENT, s.split( "//" )[1] )
        state = STATE_COMMENT
      else :
        tokens.add( TOKEN_CODE, s )
    if state is STATE_COMMENT:
      if "//" in s:
        tokens.append( TOKEN_COMMENT, s.split( "//" )[1] )
        break # get next s
      else:
        state = STATE_CODE
        # re-evaluate same line
        # continues automatically

这里有一个不同模式的更疯狂的解决方案——使用协程。代码仍然非常相似，但有一个重要的区别;根本就没有退出条件!当您停止向协程提供数据时，协程(实际上是协程链)就会停止。

def coroutine(func):
    """Coroutine decorator

    Coroutines must be started, advanced to their first "yield" point,
    and this decorator does this automatically.
    """
    def startcr(*ar, **kw):
        cr = func(*ar, **kw)
        cr.next()
        return cr
    return startcr

@coroutine
def collector(storage):
    """Act as "sink" and collect all sent in @storage"""
    while True:
        storage.append((yield))

@coroutine      
def state_machine(sink):
    """ .send() new parts to be tokenized by the state machine,
    tokens are passed on to @sink
    """ 
    s = ""
    state = STATE_CODE
    while True: 
        if state is STATE_CODE :
            if "//" in s :
                sink.send((TOKEN_COMMENT, s.split( "//" )[1] ))
                state = STATE_COMMENT
            else :
                sink.send(( TOKEN_CODE, s ))
        if state is STATE_COMMENT :
            if "//" in s :
                sink.send(( TOKEN_COMMENT, s.split( "//" )[1] ))
            else
                state = STATE_CODE
                # re-evaluate same line
                continue
        s = (yield)

tokens = []
sm = state_machine(collector(tokens))
for piece in i:
    sm.send(piece)

上面的代码将所有令牌收集为令牌中的元组，我假设原始代码中的.append()和.add()之间没有区别。

对我来说，典型的while循环是这样的:

xBool = True
# A counter to force a condition (eg. yCount = some integer value)

while xBool:
    # set up the condition (eg. if yCount > 0):
        (Do something)
        yCount = yCount - 1
    else:
        # (condition is not met, set xBool False)
        xBool = False

我也可以在while循环中包含一个for..循环，如果情况允许的话，for循环通过另一组条件。

你想知道:

为了捕捉“停止迭代”异常并正确地打破while循环，我能做些什么?

你可以这样做，如下所示，这也利用了Python 3.8中引入的赋值表达式特性(又名“海象运算符”):

list_of_ints = [1, 2, 3]
iterator = iter(list_of_ints)

try:
    while (element := next(iterator)):
        print(element)
except StopIteration:
    print("done")

另一种可能(从Python 2.6到3.x都适用)是为内置的next()函数提供一个默认参数，以避免StopIteration异常:

SENTINEL = object()  # Unique object.
list_of_ints = [1, 2, 3]
iterator = iter(list_of_ints)

while True:
    element = next(iterator, SENTINEL)
    if element is SENTINEL:
        break
    print(element)

print("done")

如果您正在循环而资源不可用或抛出异常的类似情况下，您可以使用类似于

import time

while True:
    try:
       f = open('some/path', 'r')
    except IOError:
       print('File could not be read. Retrying in 5 seconds')   
       time.sleep(5)
    else:
       break