Attributeerror: ‘list’ object has no attribute ‘join’

In any programming language, and developing programs we can’t avoid attribute errors like Attributeerror: ‘list’ object has no attribute ‘join’.

Therefore in this article, we will find solutions, example codes, as well as causes of this error.

But before that, we will discuss first this error.

What is Attributeerror: ‘list’ object has no attribute ‘join’

The AttributeError: ‘list’ object has no attribute ‘join’ occurs when we call the join() method on a list object.

Wherein a list is a data structure allowing multiple variables stores in a single. We can get this error when we are using any function that is not supported in the list object.

Here’s how this error occurs:

my_list = ['i', 't', 'c']

# AttributeError: 'list' object has no attribute 'join'
my_str = my_list.join('-')

Result:

The error is thrown when we call the join() method on the list.

How to fix Attributeerror: ‘list’ object has no attribute ‘join’

Here are the solutions we can try to fix Attributeerror: ‘list’ object has no attribute ‘join’.

Solution 1: Convert element of the list to a string

When we try to use ‘join’ method on a list of integers and specify the separator as a hyphen (“-“). We’ll get the “AttributeError: ‘list’ object has no attribute ‘join'” error.

Since the ‘join’ method is not a built-in method for lists.

Example error code:

my_list = [1, 2, 3, 4]
my_string = my_list.join("-")
print(my_string)

To fix this error, you need to convert each element of the list to a string before using the ‘join’ method, like so:

my_list = [1, 2, 3, 4]
my_string = "-".join(str(i) for i in my_list)
print(my_string)

The output of this corrected code will be:

1-2-3-4

Solution 2: Call ‘join’ method on a string instead of a list

This time as we try to use the ‘join’ method on a list of strings (‘my_list’) and specify the separator as a comma followed by a space (“, “).

Since the ‘join’ method is not a built-in method for lists – it is a string method. We got the ‘list’ object has no attribute ‘join’ error.

Example error code:

my_list = ["apple", "banana", "cherry"]
my_string = my_list.join(", ")
print(my_string)

To fix this error, you need to call the ‘join’ method on a string instead of a list, like so:

my_list = ["apple", "banana", "cherry"]
my_string = ", ".join(my_list)
print(my_string)

The output of this corrected code will be:

apple, banana, cherry

Solution 3: Convert each element of the list to a string

my_list = [1, 2, 3, 4]
my_string = my_list.join()
print(my_string)

This code tries to use the ‘join’ method on a list of integers (‘my_list’) but does not specify a separator. However, the ‘join’ method expects a separator argument, so you’ll get the “Attributeerror: ‘list’ object has no attribute ‘join’” error.

To fix this error, you need to convert each element of the list to a string and then call the ‘join’ method with an empty string as the separator, like so:

my_list = [1, 2, 3, 4]
my_string = "".join(str(i) for i in my_list)
print(my_string)

The output of this corrected code will be:

1234

Conclusion

In conclusion, we should be mindful of utilizing the Python built-in methods. Particularly, be aware of the type of data we are using and whether it is acceptable in the method we are using.

Hence the solution we provided above will fix the Attributeerror: ‘list’ object has no attribute ‘join’ error. Decide what works best for you.

If you are finding solutions to some errors you might encounter we also have  Typeerror: can’t compare offset-naive and offset-aware datetimes.