user6912880 - 8 months ago 33

Python Question

I wrote a simple program to check if strings are substrings of eachother. The issue is I keep getting a list index out of bounds error.

I tried printing i and j with each iteration and they never go out of the bounds of the list. I even tried to insert elements at s[5] and s[6] to check the index but still get the same error. What could be the cause of this error?

`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

This is my console output

`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

At the point when your code is raising the exception, the value of `i`

is `5`

and the value of `j`

is 4. In your `print`

statement you try to do `s[i]`

i.e. `s[5]`

and since max index of s is `4`

, your code is raising `IndexError`

.

I believe, in your code you need to do make modification in your `if`

statement as:

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

Then your code runs fine:

```
>>> 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"
```

Source (Stackoverflow)