python中出現string index out of range是為什麽

報錯應該是列表超出範圍了，比如

print?s[0]

>>>?h

print?s[10]

>>>?d

print?s[100]

>>>?IndexError:?string?index?out?of?range

前面2個會正常返回結果，最後壹個就會報錯超出範圍