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Python Python Basics (Retired) Shopping List Lists

Posted by chikangsong
chikangsong
755 Points

I'm confusing for using .join method.. in LIST function.

I have a stupid question but, i want to truly the reason, please help.

for example..

sentence_list = ['A', 'B', 'C', 'D', 'E'] '_'.join(sentence_list) 'A B C D E' # it can be make a string..

But, when i use this method like below there is an error Why??

sentence_list.join() Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'list object has no attribute 'join'

What does the error mean? and The join method is not a list function?

Thank you

shibashis
shibashis
8,989 Points

You cant join list, you can use join on strings. Try dir on both types of objects to see what is allowed.

1 Answer

Richard Lu
Richard Lu
20,185 Points
Richard Lu
Richard Lu
20,185 Points

If you type in help(list), you will not see the method for join. This is in fact a method of the str class. Type in help(str.join) and you'll see that the method takes any iterable object (i.e. list, tuple, string, etc.).

So for example, we could do ' * '.join(['a', 'b', 'c', 'd']) and - we'll get an output of 'a * b * c * d' or
' * '.join('abcd') - which would give you the same thing