Question

I’m trying to reverse a string and using the below code but the resultant reverse list value is None.

The code:

str_a = 'This is stirng'
rev_word = str_a.split()
rev_word = rev_word.reverse()
rev_word = ''.join(rev_word)

It returns the TypeError. Why?

Answer 1

.reverse() returns None. Therefore you should not be assigning it to a variable.

Use this instead:

stra = 'This is a string'
revword = stra.split()
revword.reverse()
revword=''.join(revword)

I’ve run the code on IDEOne for you so you can see the output. (Also notice that the output is stringaisThis; you may want to use ' '.join(revword), with a space, instead.)

Also note that the method you have provided only reverses the words, not the text. @ron.rothman provided a link that does detail how to reverse a string in its entirety.