列表索引超出範圍，雖然看起來不是

Question

我寫了一個簡單的程序來檢查字符串是否是彼此的子字符串。問題是我不斷收到列表索引超出界限的錯誤。

我試着在每次迭代時打印i和j，並且它們從不超出列表的範圍。我甚至試圖在s [5]和s [6]處插入元素來檢查索引，但仍然得到相同的錯誤。可能是這個錯誤的原因是什麼？

s = []           
s.insert(0,str("a b c")) 
s.insert(1,str("a b c d")) 
s.insert(2,str("a b")) 
s.insert(3,str("b c")) 
s.insert(4,str("d")) 

j = 0 
i = 0 

while j < 5: 
    if s[j] in s[i]: 
     print("\"" + s[j] + "\" is in the string \"" + s[i] + "\"") 
    i +=1 
    if i == 5 and j < 4: 
     j+=1 
     i=0 

這是我的控制檯輸出

Traceback (most recent call last): 
"a b c" is in the string "a b c" 
    File "C:/Users/Kal/PycharmProjects/untitled/FSS2.py", line 16, in <module> 
"a b c" is in the string "a b c d" 
    if s[j] in s[i]: 
"a b c d" is in the string "a b c d" 
IndexError: list index out of range 
"a b" is in the string "a b c" 
"a b" is in the string "a b c d" 
"a b" is in the string "a b" 
"b c" is in the string "a b c" 
"b c" is in the string "a b c d" 
"b c" is in the string "b c" 
"d" is in the string "a b c d" 
"d" is in the string "d" 

Process finished with exit code 1 

Answer 1

在點當你的代碼是提高外，中i值5和j值爲4.在print聲明你嘗試做s[i]即s[5]，自S的最高指數爲4，你代碼正在提高IndexError。

我相信，在你的代碼，你需要做的做修改您的if語句：

if i == 5 and j < 5: # Instead of j < 4 

那麼你的代碼運行正常：

>>> while j < 5: 
...  if s[j] in s[i]: 
...   print("\"" + s[j] + "\" is in the string \"" + s[i] + "\"") 
...  i +=1 
...  if i == 5 and j < 5: 
...   j+=1 
...   i=0 
... 
"a b c" is in the string "a b c" 
"a b c" is in the string "a b c d" 
"a b c d" is in the string "a b c d" 
"a b" is in the string "a b c" 
"a b" is in the string "a b c d" 
"a b" is in the string "a b" 
"b c" is in the string "a b c" 
"b c" is in the string "a b c d" 
"b c" is in the string "b c" 
"d" is in the string "a b c d" 
"d" is in the string "d" 

Answer 2

你似乎j增加，只有當我已經是5（注意，如果子句中的and）。因此，當i = 5時，你仍然處於while循環（它只取決於j），並且嘗試訪問未定義的s [i] = s [5]。

Answer 3

的問題是在該行18

s = []           
s.insert(0,str("a b c")) 
s.insert(1,str("a b c d")) 
s.insert(2,str("a b")) 
s.insert(3,str("b c")) 
s.insert(4,str("d")) 
print(s) 
j = 0 
i = 0 

while j < 5: 
    if s[j] in s[i]: 

     print("\"" + s[j] + "\" is in the string \"" + s[i] + "\"") 
    i +=1 
    if i == 5 and j < 4: <-- here 
     j+=1 
     i=0 

在某些時候，您的i = 5和j = 4，所以這個if i == 5 and j < 4語句的右側爲False，並且i沒有那麼在下一個循環reseted爲0時，i等於5，最大指數爲4。

更好的解決辦法要使用for循環。

s = []           
s.insert(0,str("a b c")) 
s.insert(1,str("a b c d")) 
s.insert(2,str("a b")) 
s.insert(3,str("b c")) 
s.insert(4,str("d")) 
for i in range(len(s)): 
    for j in range(len(s)): 
     if s[i] in s[j]: 
      print("\"" + s[i] + "\" is in the string \"" + s[j] + "\"") 

編輯回答評論

s = []           
s.insert(0,str("a b c")) 
s.insert(1,str("a b c d")) 
s.insert(2,str("a b")) 
s.insert(3,str("b c")) 
s.insert(4,str("d")) 
j = 0 
i = 0 

while j < len(s): 
    if s[j] in s[i]: 
     print("\"" + s[j] + "\" is in the string \"" + s[i] + "\"") 
    i +=1 
    if i == len(s): 
     j+=1 
     i=0 

Answer 4

你的i和j變量在while循環是不正確的。在代碼運行後更改值後。

s = []           
s.insert(0,str("a b c")) 
s.insert(1,str("a b c d")) 
s.insert(2,str("a b")) 
s.insert(3,str("b c")) 
s.insert(4,str("d")) 

print s 

j = 0 
i = 0 

while j < 5: 
    if s[j] in s[i]: 
     print("\"" + s[j] + "\" is in the string \"" + s[i] + "\"") 
    i +=1 
    if i == 4 and j < 5: 
     j+=1 
     i=0 

Answer 5

保持您的形式，它是：

s = []           
s.insert(0,str("a b c")) 
s.insert(1,str("a b c d")) 
s.insert(2,str("a b")) 
s.insert(3,str("b c")) 
s.insert(4,str("d")) 

j = 0 
i = 0 

while j < 5: 
    if s[j] in s[i]: 
     print("\"" + s[j] + "\" is in the string \"" + s[i] + "\"") 
    i +=1 
    if i == 5 and j <= 4: 
     j+=1 
     i=0 

的錯誤是在第二，如果你while循環。它應該是j <= 4或j < 5才能工作。