Creating a String in Python 3 using indexing

Question

I need to create a string that returns the characters from the column of the board with index column_index as a single string.

I need to return the below

>>> make_str_from_column([['A', 'N', 'T', 'T'], ['X', 'S', 'O', 'B']], 1)
'NS

I had initially done

def makedef make_str_from_column(board, column_index):
    """ (list of list of str, int) -> str """
    if column_index >=0:
        return board[0][column_index] +board[1][column_index]

however, I cannot use the 0 and 1 these are really just hardcoded to get me to the answer I want

I am a bit lost on how to replace the 0 and 1

Welcome to Stackoverflow! Please edit your question to format the code samples as code. Highlight it and click on the { } button — jwebb, Sep 20 '18 at 14:25

score 0 · Answer 1 · answered Sep 20 '18 at 14:27

0

Something like this

def makedef make_str_from_column(board, column_index): 
  if len(board) == 0:
    return ''
  if column_index >=0 and column_index < len(board[0]): 
    return ''.join([board[i][column_index] for i in range(len(board))])

answered Sep 20 '18 at 14:27

Atul Shanbhag

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do I really need the first if statement? – Wildcats-99 Sep 20 '18 at 14:37
That is because I am doing len(board[0]) in the next if statement – Atul Shanbhag Sep 20 '18 at 14:38
can you explain to me what the len(board[0]) is doing? is that showing that there are 4 columns? – Wildcats-99 Sep 20 '18 at 14:54
Yes, I am assuming all lengths inside the board (board[0], board[1], etc) are equal and then checking if column_index < len(board[0]) because otherwise it will throw an error – Atul Shanbhag Sep 20 '18 at 14:55
the i , how does python view the i? I think that is where I am getting caught up – Wildcats-99 Sep 20 '18 at 17:53
I am running a loop for `for i in range(len(board))` so i will start from 0 and go to len(board) - 1, in your case since len(board) is 2, i will be 0 then 1 – Atul Shanbhag Sep 20 '18 at 17:58

Creating a String in Python 3 using indexing

1 Answers1