擅长:python、mysql、java
<p><code>break</code>仅中断内部<code>for</code>循环。
最好将所有内容放入函数中,并使用<code>return</code>停止<code>while</code>循环:</p>
<pre><code>def main():
while True:
chosenUser = raw_input("Enter a username: ")
with open("userDetails.txt", "r") as userDetailsFile:
for line in userDetailsFile:
if chosenUser in line:
print "\n"
print chosenUser, "has taken previous tests. "
return # stops the while loop
print "That username is not registered."
main()
print 'keep going here'
</code></pre>