擅长:python、mysql、java
<p>改为使用范围为的for循环:</p>
<pre><code>exsentence = input("Enter a sentence to scan: ")
slist = list(exsentence.lower())
ch = 0
sh = 0
th = 0
wh = 0
i = 0
'''muppets = slist[i] + slist[i+1]'''
for i in range(1,len(slist)):
if slist[i-1] + slist[i] == "sh":
sh += 1
elif slist[i-1] + slist[i] == "ch":
ch += 1
elif slist[i-1] + slist[i] == "th":
th += 1
elif slist[i-1] + slist[i] == "wh":
wh += 1
print(f"Has {ch} 'ch' {sh} 'sh' {th} 'th' {wh} 'wh'")
</code></pre>
<p>从1开始,检查i-1和i,这样你就不会超出索引范围</p>