<p>在这里:</p>
<pre><code>def main():
list=["chocolate", "jelly", "biscuits"]
eat=input("What do you wanna eat?")
for element in list:
index = list.index(element)
if element == eat:
print("We have that in tray:", index)
break
# If the element is found, then print the message and stop the loop
elif index == len(list) - 1:
# Index starts form 0, then if you have a list with n elements
# and you reach the element with index n-1, you have reached
# the last element.
print("that is not in the list")
# if the element is the last in the list, and it's not
# equal to the user input, then the user input is not in the
# list. Print the error message.
main()
</code></pre>
<p>使用<code>enumerate</code></p>
<pre><code>def main():
list=["chocolate", "jelly", "biscuits"]
eat=input("What do you wanna eat?")
for index,element in enumerate(list):
if element == eat:
print("We have that in tray:", index)
break
elif index == len(list) - 1:
print("that is not in the list")
main()
</code></pre>