16.Using strings in functions

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#1

Hi! I tried to do this using the append function:



n = ["Michael", "Lieberman"]
def join_strings(words):
    result=""
    for i in range(len(words)):
        result=result.append(words[i])
    return result


print join_strings(n)

got error: error: AttributeError: ‘str’ object has no attribute ‘append’
And when I saw the solution I realized that append works on lists and not strings! :slight_smile: I was stuck yesterday because the wording of the exercise confused me that I should use the append function! Just a reminder that append doesnt work with str, seems like. Also important to note is that if ur using the simpler method of for i in words: - you can use both result+=i and result+=words[i] but if ur using the more complicated range one you should always use result+=words[i]. Im just curious why it cant work without me pointing out that i is an index in words list? Some help?

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#2

well, if you use the range function, you will get numbers:

n = ["Michael", "Lieberman"]
for i in range(len(n)):
   print i
   print n[i]

Then you can use the numbers to access the item at that particular item, python also allows you to use for in without range:

n = ["Michael", "Lieberman"]
for i in n:
    print i

which will gives you the names directly

#3

from what I understand, your supposed to use “result.join(words[i])”
however it doesn’t seem to be working

however result += words[i] works

hmm, seem like another of codecademy’s poorly worded exercises

#4

This is the good things, there are multiply ways to solve the problem. If you want to append to a string you can use +=, but you can also use .join, but then you would have to use it correctly:

n = ["Michael", "Lieberman"]
def join_strings(words):
    result =  "".join(words)
    return result
print join_strings(n)

Your join simple contains too many flaws. where you have result, that should be what should be used to join "" simply means nothing, "-" would have given Michael-Lieberman, and you can call join directly on a list, no need to loop it

3 Likes
#6

Thanks for the great response, @stetim94

Follow-up question: Is there a way to use append in this context? If not, can you please explain specifically why it wouldn’t work (and maybe where it would be applicable)?_

#7

you could concat/join the string together:But not with append, because the .append() function is only for lists.

you would get something like this:

n = ["Michael", "Lieberman"]
def join_strings(words):
    x = ""
    for i in words:
        x += i
    return x

print join_strings(n)

you just join the string with +, just like you would do to join/concat a string for printing, except this time you store it in a variable. This is nothing new, right?

2 Likes
#8

@stetim94 i tried what you wrote but my error message says “Oops, try again. string_function(‘Hello’) returned ‘H’ instead of ‘Helloworld’” In my output box it says “MichaelLieberman None”

What should I do?

From- @byteace83915

#9

Please create a new topic with your code + error message + question, thank you.

#11

as stetim94 said:

if you used result += words[i] it will join them to the the string without any spaces or flaws
but “”.join(words) will join them with flaws and you can add any flaws you want

#13

Thanks for your explanation on whether if you should use the .append() function in this exercise. (I had trouble with this exercise as well.) :slight_smile: