importmatplotlib.pyplotaspltfrommatplotlibimportrcParamsfrommatplotlibimportcycler# from cycler import cycler works finecc=cycler('linestyle', [(0,(3,1)),'-'])fig=plt.figure()ax=fig.add_subplot(221)ax.set_prop_cycle(cc)ax.plot(range(10))

Traceback (most recent call last):  File "err.py", line 10, in <module>    ax.plot(range(10))  File "/usr/local/lib/python3.7/site-packages/matplotlib/axes/_axes.py", line 1665, in plot    lines = [*self._get_lines(*args, data=data, **kwargs)]  File "/usr/local/lib/python3.7/site-packages/matplotlib/axes/_base.py", line 225, in __call__    yield from self._plot_args(this, kwargs)  File "/usr/local/lib/python3.7/site-packages/matplotlib/axes/_base.py", line 405, in _plot_args    seg = func(x[:, j % ncx], y[:, j % ncy], kw, kwargs)  File "/usr/local/lib/python3.7/site-packages/matplotlib/axes/_base.py", line 312, in _makeline    seg = mlines.Line2D(x, y, **kw)  File "/usr/local/lib/python3.7/site-packages/matplotlib/lines.py", line 377, in __init__    self.set_linestyle(linestyle)  File "/usr/local/lib/python3.7/site-packages/matplotlib/lines.py", line 1186, in set_linestyle    cbook._check_in_list([*self._lineStyles, *ls_mapper_r], ls=ls)  File "/usr/local/lib/python3.7/site-packages/matplotlib/cbook/__init__.py", line 2170, in _check_in_list    .format(v, k, ', '.join(map(repr, values))))ValueError: '(0, (3, 1))' is not a valid value for ls; supported values are '-', '--', '-.', ':', 'None', ' ', '', 'solid', 'dashed', 'dashdot', 'dotted'