TypeError: got multiple values for argument

This happens when a keyword argument is specified that overwrites a positional argument. For example, let's imagine a function that draws a colored box. The function selects the color to be used and delegates the drawing of the box to another function, relaying all extra arguments.

def color_box(color, *args, **kwargs):
    painter.select_color(color)
    painter.draw_box(*args, **kwargs)

Then the call

color_box("blellow", color="green", height=20, width=30)

will fail because two values are assigned to color: "blellow" as positional and "green" as keyword. (painter.draw_box is supposed to accept the height and width arguments).

This is easy to see in the example, but of course if one mixes up the arguments at call, it may not be easy to debug:

# misplaced height and width
color_box(20, 30, color="green")

Here, color is assigned 20, then args=[30] and color is again assigned "green".

I had the same problem that is really easy to make, but took me a while to see through.

I had copied the declaration to where I was using it and had left the self argument there, but it took me ages to realise that.

I had

self.my_method(self, a, b, c='123')

but it should have been

self.my_method(a, b, c='123')

This also happens if you forget selfdeclaration inside class methods.

Example:

class Example():
    def is_overlapping(x1, x2, y1, y2):
        # Thanks to https://stackoverflow.com/a/12888920/940592
        return max(x1, y1) <= min(x2, y2)

Fails calling it like self.is_overlapping(x1=2, x2=4, y1=3, y2=5) with:

{TypeError} is_overlapping() got multiple values for argument 'x1'

WORKS:

class Example():
    def is_overlapping(self, x1, x2, y1, y2):
        # Thanks to https://stackoverflow.com/a/12888920/940592
        return max(x1, y1) <= min(x2, y2)

I was brought here for a reason not explicitly mentioned in the answers so far, so to save others the trouble:

The error also occurs if the function arguments have changed order - for the same reason as in the accepted answer: the positional arguments clash with the keyword arguments.

In my case it was because the argument order of the Pandas set_axis function changed between 0.20 and 0.22:

0.20: DataFrame.set_axis(axis, labels)
0.22: DataFrame.set_axis(labels, axis=0, inplace=None)

Using the commonly found examples for set_axis results in this confusing error, since when you call:

df.set_axis(['a', 'b', 'c'], axis=1)

prior to 0.22, ['a', 'b', 'c'] is assigned to axis because it's the first argument, and then the positional argument provides "multiple values".