Changing values of the array but the code does not go into the if else statement (Python)

The Code does not go in the If Statement no matter what (where I intend to alter the array "dop", I have no idea why. Any Help will be appreciated

#The Array dop
dop = ["1878[1879]","1877","[2016]2015","1874","[2871]2987","3012[2019]"]

i = 0;

#Used Try Catch Block because of the Type Error that occurs when '[' is not found in an array 
#Element
while(i < 6):
   try:
     strObject = dop[i]
     print(strObject)
     indexOne = strObject.index('[',0)
     indexTwo = strObject.index(']',0)

     print(indexOne)
     print(indexTwo)

     if (indexOne != 0 | indexOne != -1):
         substringObject = strObject[0:indexOne]
         dop[i] = substringObject
         i = i+1
         print(i)
     elif (indexOne == -1):
         i = i+1
     elif (indexOne == 0):
         substringObject = strObject[indexTwo]
         dop[i] = substringObject
         i = i+1
   except ValueError:
       print("Goes Here")
       i = i+1
       print(i)
   i = i+1