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helmi al kindy
1,371 PointsHow do I get an array to become a string ?
In this exercise I have to print out a string but it comes out as a list. It says I have to use the .join() but when I do I get an error that says AttributeError: 'list' object has no attribute 'join' What does that mean ? How do I use the join method for this exercise ?
full_name = 'jon doe'
name_list = full_name.split()
greeting_list = "Hi, I'm Treehouse".split()
greeting_list[2] = name_list[0]
greeting = str(greeting_list)
2 Answers
Chris Freeman
Treehouse Moderator 68,423 PointsIt is not obvious how to use join. join() is a string method and can not be used on a list, as you found out. Using help(str.join) for help:
join(...)
S.join(iterable) -> str
Return a string which is the concatenation of the strings in the
iterable. The separator between elements is S.
This means, use the string separator defined as S to join the items in the iterable. So to join the items in greeting_list with spaces, S would be a string with a single space: " ":
greeting = " ".join(greeting_list)
helmi al kindy
1,371 PointsSo let's assume x = [1, 2, 3] Would x be the object and 1, 2 and 3 be its attributes ?
Chris Freeman
Treehouse Moderator 68,423 PointsNot exactly. The items in the list x such as the number 1 are objects in themselves which are referenced by the list, but are not attributes of x. If you want to see the attributes of a specific list, such as x, use the python statement dir(x)
helmi al kindy
1,371 Pointshelmi al kindy
1,371 PointsOK thanks, but what is an attribute error ?
Chris Freeman
Treehouse Moderator 68,423 PointsChris Freeman
Treehouse Moderator 68,423 PointsThis might be a little too deep of an explanation....
Attributes are the items within a class. This includes methods of an object class such as upper() for strings:
str.upper()and append() for lists:list.append(). As you start to create class objects you will learn more on this.You may often hear "everything in python is an object". Well, all of the items within an object are attributes of that object. When trying to interpret your code, python looks up the attributes you reference within each object. So when trying to use
joinon a list, it looks up the methodjoinwithin the attributes of thelistobject. Because it does not exist for a list, there is no join attribute. Thus the error returned by python is an "AttributeError".