Python ValueError and IndexError

I have been given a project to work on for school where I am to determine the number of elementary steps in two separate lists of cities.

When I try to run the project in order to answer this problem, I get two separate errors depending on which list I am trying to run.

Here is the code below

"""  This program sorts the words " London " , " Canterbury " , " York " and " Leicester "  by their length (in ascending order) and prints the result out.  """    # First , we define our input as an array of strings  cities = ["London", "Canterbury", "York", "Leicester"]    # You can  also  try it with a very  long  list. Uncomment  this  line to do so.  #cities = ['Lancaster', 'Sunderland', 'Wolverhampton', 'Nottingham', 'Oxford', 'Plymouth', 'Salisbury', 'Salford', 'Wakefield', 'Lichfield', 'Wells', 'Preston', 'Brighton  and  Hove', 'St  Albans', 'Kingston  upon  Hull', 'Chichester', 'Durham', 'Liverpool', 'Bath', 'Bradford', 'Cambridge', 'Ely', 'York', 'Exeter', 'Birmingham', 'Carlisle', 'Portsmouth', 'Chester', 'Ripon', 'Coventry', 'Gloucester', 'Sheffield', 'Winchester', 'Lincoln', 'Canterbury', 'Westminster', 'Newcastle  upon  Tyne', 'Peterborough', 'Worcester', 'Leeds', 'Norwich', 'Stoke -on-Trent', 'Southampton', 'Bristol', 'Derby', 'Truro', 'Manchester', 'Hereford', 'City of  London', 'Leicester']    # Initialize our result , which will be empty for now  result = []    # Initialize our loop variables  i = 0  j = 0  number_of_cities = len(cities)  # len () of a list gives you the number of elements in it  # len () of a string will give you the length of it    n = number_of_cities  number_of_steps = 0    # Sort using selection sort  for i in range(0, number_of_cities):      minimum_length = len(cities[0])      minimum_element = cities[0]        for j in range(0, n):          if (len(cities[j]) < minimum_length):              minimum_length = len(cities[j])              minimum_element = cities[j]              number_of_steps = number_of_steps + 1            # At the end of the second loop , we will have the shorter element in minimum_element          # We just need to add it to our results and remove it from our working list            result.append(minimum_element)          cities.remove(minimum_element)          n = n - 1    print("")  print("The ordered list is:")  print(str(result))  print("The list had " + str(number_of_cities) + " cities and I ordered it in " + str(number_of_steps) + " steps .")  

When I try to run the program with list cities = ["London", "Canterbury", "York", "Leicester"] I get the following error: IndexError: list index out of range

When I try to run the program with list cities = ['Lancaster', 'Sunderland', 'Wolverhampton', 'Nottingham', 'Oxford', 'Plymouth', 'Salisbury', 'Salford', 'Wakefield', 'Lichfield', 'Wells', 'Preston', 'Brighton and Hove', 'St Albans', 'Kingston upon Hull', 'Chichester', 'Durham', 'Liverpool', 'Bath', 'Bradford', 'Cambridge', 'Ely', 'York', 'Exeter', 'Birmingham', 'Carlisle', 'Portsmouth', 'Chester', 'Ripon', 'Coventry', 'Gloucester', 'Sheffield', 'Winchester', 'Lincoln', 'Canterbury', 'Westminster', 'Newcastle upon Tyne', 'Peterborough', 'Worcester', 'Leeds', 'Norwich', 'Stoke -on-Trent', 'Southampton', 'Bristol', 'Derby', 'Truro', 'Manchester', 'Hereford', 'City of London', 'Leicester'] I receive the following error cities.remove(minimum_element) ValueError: list.remove(x): x not in list

Any advice on how to fix this issue? I'm unsure if I can change the code much because this is what we have been given to work on. It's the holidays and all my lecturers are out of office so I'm unable to get any help. Thanks

https://stackoverflow.com/questions/65403068/python-valueerror-and-indexerror December 22, 2020 at 11:56AM