"Can only join an iterable" python error

Question

I've already looked at this post about iterable python errors:

"Can only iterable" Python error

But that was about the error "cannot assign an iterable". My question is why is python telling me:

 "list.py", line 6, in <module>
    reversedlist = ' '.join(toberlist1)
TypeError: can only join an iterable

I don't know what I am doing wrong! I was following this thread:

Reverse word order of a string with no str.split() allowed

and specifically this answer:

>>> s = 'This is a string to try'
>>> r = s.split(' ')
['This', 'is', 'a', 'string', 'to', 'try']
>>> r.reverse()
>>> r
['try', 'to', 'string', 'a', 'is', 'This']
>>> result = ' '.join(r)
>>> result
'try to string a is This'

and adapter the code to make it have an input. But when I ran it, it said the error above. I am a complete novice so could you please tell me what the error message means and how to fix it.

Code Below:

import re
list1 = input ("please enter the list you want to print")
print ("Your List: ", list1)
splitlist1 = list1.split(' ')
tobereversedlist1 = splitlist1.reverse()
reversedlist = ' '.join(tobereversedlist1)
yesno = input ("Press 1 for original list or 2 for reversed list")
yesnoraw = int(yesno)
if yesnoraw == 1:
    print (list1)
else:
    print (reversedlist)

The program should take an input like apples and pears and then produce an output pears and apples.

Help would be appreciated!

Laryngology

Answer 1

splitlist1.reverse(), like many list methods, acts in-place, and therefore returns None. So tobereversedlist1 is therefore None, hence the error.

You should pass splitlist1 directly:

splitlist1.reverse()
reversedlist = ' '.join(splitlist1)

Candelaria

How would you make the program reverse lists that include commas? Like apples,pears go to pears,apples – Laryngology

Pass a comma to split instead of a space. – Candelaria

How would you do both the space split and comma split at the same time? This is so yo can enter both apples,pear and apples pears regardless of the code. – Laryngology

There's a few ways, but probably the easiest is to replace the spaces with commas first, then split on commas: splitlist1 = list1.replace(' ', ',').split(',') – Candelaria

Answer 2

string join must satisfy the connection object to be iterated(list, tuple)

splitlist1.reverse() returns None, None object not support iteration.

Jeromyjerreed

Answer 3

def mostActive(customers):
    total = len(customers)
    dict_ = {}
    for i in customers:
        dict_[i] = dict_.get(i, 0) + 1
    res = {}
    for i in dict_:
        res[i] = (dict_[i]/total)*100
    print(res)
    traders = []
    for i in res:
        if res[i] >= float(5):
            traders.append(i)
    return (sorted(traders))

Synopsis