我想在python中的while循环中只打印一次

Question

代码：

while True:
 text = 'fizz'
 if text == 'fizz':
  print('fizz')
 elif text == 'buzz':
  print('buzz')

如果text = 'fizz'我想打印一次 fizz 并且如果我用 text = 'buzz' 替换text = 'fizz' text = 'buzz'它会打印嗡嗡声。

Answer 1

使用标志变量来指示是否已打印任何内容。 如果已设置，请勿再次打印。

printed = False
while True:
    text = 'fizz'
    if not printed:
        if text == 'fizz':
            print('fizz')
            printed = True
        elif text == 'buzz':
            print('buzz')
            printed = True

Answer 2

您可以通过多种方式执行此操作：

printed = False
while not printed:
 text = 'fizz'
 if text == 'fizz':
  print('fizz')
  printed = True
 elif text == 'buzz':
  print('buzz')
  printed = True

while True:
 text = 'fizz'
 if text == 'fizz':
  print('fizz')
  break
 elif text == 'buzz':
  print('buzz')
  break

Answer 3

如果你想选择你的嘶嘶声程序的结果，请使用input()

版本 1

while True:
    # Each new loop it starts by asking for fizz or buzz
    # If something other than fizz or buzz is typed in
    # the code will print nothing and loop again
    text = input('fizz or buzz?: ')
    if text == 'fizz':
        print('fizz')
    if text == 'buzz':
        print('buzz')
    

如果您希望您的程序每次都在两者之间切换，请使用此代码

版本 2

while True:
    text = 'fizz'
    if text == 'fizz':
        text = 'buzz'  # switch fizz for buzz
        print('fizz')
    if text == 'buzz':
        text = 'fizz'  # switch buzz for fizz
        print('buzz')
    # I added a = input() because without it,
    # It would loop hundreds of times a second 
    # printing fizz buzz over and over
    a = input()

如果您希望您的代码打印一次两者之一，请使用此代码

版本 3

def fizz_buzz():
    text = 'fizz'
    if text == 'fizz':
        print('fizz')
    if text == 'buzz':
        print('buzz')


printing = True
while True:
    if printing:
        fizz_buzz()
        printing = False

使用过程使 while 语句更整洁，因为嵌套 if 语句并在 while 循环中加载使其更难阅读。