[Solved] TypeError: list.extend() takes exactly one argument (2 given)

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This error means you gave two arguments to list.extend(), which only takes one. You probably are trying to add two items to the list. The fix is simple, just wrap those two items in brackets ([]) to make them a list, and therefore only one argument.

Problem: you passed 2 arguments to list.extend()

If you have two items you want to add to a list, and you try to pass them by themselves as arguments to extend like the following, it won’t work:

foo = ["a", "b", "c"]
foo.extend("d", "e")
Python

Instead, you’ll get the following stack trace:

Traceback (most recent call last):
  File "/home/user/main.py", line 2, in <module>
    foo.extend("d", "e")
TypeError: list.extend() takes exactly one argument (2 given)

Just as it says, you can’t add two items to the list by passing them as separate arguments. Instead, you’ll have to make them only one argument.

Solution 1: wrap the two arguments in a list

This is one way to make your two arguments into one argument:

foo = ["a", "b", "c"]
foo.extend(["d", "e"])

print(foo)
# -> ['a', 'b', 'c', 'd', 'e']
Python

Solution 2: wrap the two arguments in a tuple

Alternatively, you can use parenthesis () to make your two items into a single argument:

foo = ["a", "b", "c"]
foo.extend(("d", "e"))

print(foo)
# -> ['a', 'b', 'c', 'd', 'e']
Python

Conclusion

In Python, you can’t pass more than one argument to list.extend(). It expects another list, or a tuple, or some other kind of iterable as its only argument. So, to fix it, just wrap your items in brackets or parenthesis to make them into a single list or tuple respectively before passing them to list.extend().