Not compatible with pandas copy on write

[rmnldwg]

First of all, thanks for the nice package! This allows me to nicely visualize my research!

However, I stumbled across this issue: Pandas recommends to turn on "copy-on-write" as it will become the default in pandas 3. But this feature breaks the upsetplot package.

Here a minimal script that reproduces the failure:

import pandas as pd
from upsetplot import plot, generate_counts

pd.options.mode.copy_on_write = True

plot(generate_counts())

This raises the following exception:

Traceback (most recent call last):
  File "/home/user/test.py", line 6, in <module>
    plot(generate_counts())
  File "/home/user/.venv/lib/python3.10/site-packages/upsetplot/plotting.py", line 1158, in plot
    return UpSet(data, **kwargs).plot(fig)
  File "/home/user/.venv/lib/python3.10/site-packages/upsetplot/plotting.py", line 1098, in plot
    self.plot_matrix(matrix_ax)
  File "/home/user/.venv/lib/python3.10/site-packages/upsetplot/plotting.py", line 810, in plot_matrix
    ax.scatter(
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/__init__.py", line 1465, in inner
    return func(ax, *map(sanitize_sequence, args), **kwargs)
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/axes/_axes.py", line 4744, in scatter
    collection = mcoll.PathCollection(
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/collections.py", line 1027, in __init__
    super().__init__(**kwargs)
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/collections.py", line 174, in __init__
    self.set_edgecolor(edgecolors)
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/collections.py", line 834, in set_edgecolor
    self._set_edgecolor(c)
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/collections.py", line 813, in _set_edgecolor
    self._edgecolors = mcolors.to_rgba_array(c, self._alpha)
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/colors.py", line 505, in to_rgba_array
    rgba = np.array([to_rgba(cc) for cc in c])
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/colors.py", line 505, in <listcomp>
    rgba = np.array([to_rgba(cc) for cc in c])
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/colors.py", line 302, in to_rgba
    rgba = _to_rgba_no_colorcycle(c, alpha)
  File "/home/user/.venv/lib/python3.10/site-packages/matplotlib/colors.py", line 391, in _to_rgba_no_colorcycle
    raise ValueError(f"Invalid RGBA argument: {orig_c!r}")
ValueError: Invalid RGBA argument: nan

And even with copy-on-write set to False, pandas spits out a lot of warnings like this one:

ChainedAssignmentError: A value is trying to be set on a copy of a DataFrame or Series through chained assignment using an inplace method.
When using the Copy-on-Write mode, such inplace method never works to update the original DataFrame or Series, because the intermediate object on which we are setting values always behaves as a copy.

For example, when doing 'df[col].method(value, inplace=True)', try using 'df.method({col: value}, inplace=True)' instead, to perform the operation inplace on the original object.

I was using the following setup to run the minimal "working" example:

OS	Ubuntu 22.04.4 LTS on Windows 10 x86_64
Python	3.10.12
matplotlib	3.8.3
pandas	2.2.1