Btukfyl

I am working on some Code Signal practice problems in Python 2 and I have been running into the same error a lot. Like the title of the question says, I can not access a specific list element even though i am sure it exists. When I try to run the code shown below I get this error, IndexError: list index out of range. Shown below is some code I am working with. Any help is appreciated, i'm sure this is a simple misunderstanding of how Python2 works. In this example
s = "adobecodebanc" and t is not relevant for my question

    def minSubstringWithAllChars(s, t):

        nuS = str(s)

        listS = list(nuS)



        for i in range(len(listS)):

            print i

            print listS[i]



        print listS[0]

When I omit the last line of code I am able to print all of the characters that are in S - as shown below. However, when I add the last line, I am unable to print anything as a I get an indexing error.

    0

    a

    1

    d

    2

    o

    3

    b

    4

    e

    5

    c

    6

    o

    7

    d

    8

    e

    9

    b

    10

    a

    11

    n

    12

    c

What could this be due to? Here is the text of my error message

          Traceback (most recent call last):

            file.py on line ?, in getUserOutputs

              userOutput = _runjodsn(testInputs[i])

            file.py on line ?, in _runjodsn

              return minSubstringWithAllChars(*_fArgs_nycavblqytqu)

            file.py on line 9, in minSubstringWithAllChars

              print listS[0]

          IndexError: list index out of range

You probably are running into a strange issue with your provider python compiler or maybe, since it's a page with a web application to test, run and validate python exercices, your code is not running exactly the way you see it on the web page.

This can be clearly spoted if you compare your code to the stacktrace, which has additional calls and even the arguments for your function don't seem to be standard formal arguments, but a *args (non-keyworded variable length argument) argument.

A stacktrace for an IndexError for your code (for example if your string argument was empty, would be):

Traceback (most recent call last):

  File "main.py", line 11, in <module> 

    minSubstringWithAllChars("abe", "") 

  File "main.py", line 9, in minSubstringWithAllChars 

    print listS[0] 

IndexError: list index out of range

Anyway, running With python 2.7.13 clearly shows no problem with your code:

def minSubstringWithAllChars(s):

    nuS = str(s)

    listS = list(nuS)

    print("working with string: " + nuS)

    print("Len of s: " + str(len(nuS)))

    print("Len of listS: " + str(len(listS)))

    print("n")



    for i in range(len(listS)):

        print("Checking position: " + str(i) + " of String (" + nuS + "): " + listS[i])



    print("nAdditional access to listS via index 0: ")

    print listS[0]



print("Startn")

minSubstringWithAllChars("adobecodebanc")

print("nEnd")

You can see it works:

Start



working with string: adobecodebanc

Len of s: 13

Len of listS: 13





Checking position: 0 of String (adobecodebanc): a

Checking position: 1 of String (adobecodebanc): d

Checking position: 2 of String (adobecodebanc): o

Checking position: 3 of String (adobecodebanc): b

Checking position: 4 of String (adobecodebanc): e

Checking position: 5 of String (adobecodebanc): c

Checking position: 6 of String (adobecodebanc): o

Checking position: 7 of String (adobecodebanc): d

Checking position: 8 of String (adobecodebanc): e

Checking position: 9 of String (adobecodebanc): b

Checking position: 10 of String (adobecodebanc): a

Checking position: 11 of String (adobecodebanc): n

Checking position: 12 of String (adobecodebanc): c



Additional access to listS via index 0: 

a



End

Another thing is that you don't need to use indexes to iterate your string characters (or break your string into an array of characters with list()). You can just shortcut with this:

for i in nuS:

    print i