How do i make this list into a string in python?

Question

I am trying, in the following code, to encrypt a message. The problem is that my result comes up in a list format instead of a string. How do I make it into a string?

As far as I can tell, you are trying to do create a string of alternating characters. You want this: `def stringEncrypter(A): return "".join(A[0:-1:2] + A[1:-1:2])` — hughdbrown, Mar 12 '13 at 20:34

Pavel Anossov · Answer 1 · 2013-03-12T15:50:59.783

2

finalArray is clearly a list:

finalArray = []

To convert it to a string, use join:

print ''.join(finalArray)

But first, you probably do not want these nested lists. You should use extend, not append:

def stringEncrypter(A):
    length = len(A)
    finalArray = []

    if length%2 == 0:
            firstArray=[]*(length/2)
            secondArray=[]*(length/2)
    else:
            firstArray=[]*((length+1)/2)
            secondArray=[]*((length-1)/2)

    for x in range(0, length-1):
            if x%2 == 0:
                    firstArray.append(A[x:x+1])
                    secondArray.append(A[x+1:x+2])
    finalArray.extend(firstArray)
    finalArray.extend(secondArray)

    print ''.join(finalArray)

edited Mar 12 '13 at 15:50

answered Mar 12 '13 at 15:38

Pavel Anossov

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But, this won't work when `finalArray` is a list of lists, as it is in the question. – Tom Offermann Mar 12 '13 at 15:49
Yes, I changed `append` to `extend` and forgot to mention it. – Pavel Anossov Mar 12 '13 at 15:52
Yes this worked. Extend was what i needed. join didnt work without it. Thank you – user2097674 Mar 14 '13 at 11:42

score 2 · Answer 2 · answered Mar 12 '13 at 15:47

2

You need to flatten the nested lists in your result and then turn it into a string. Here's one way to do it:

>>> import itertools
>>> result = [['I', 'R', 'A', ' ', 'O'], [' ', 'E', 'D', 'Y', 'U']]
>>> ''.join(itertools.chain(*result))
'IRA O EDYU'

answered Mar 12 '13 at 15:47

Tom Offermann

1,391
12
12

1

Or you can pass the list to `itertools.chain.from_iterable` – Acorn Mar 12 '13 at 15:51

How do i make this list into a string in python?

2 Answers2