TypeError: must be real number, not str


### matplotlibのバージョン変更したら、下記のエラーが発生した。
Error in callback <function install_repl_displayhook.<locals>.post_execute at 0x7f6fddedc8c0> (for post_execute):

### エラー内容
```---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/opt/anaconda3/lib/python3.7/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

/opt/anaconda3/lib/python3.7/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
--> 246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))
    247     if 'jpg' in formats or 'jpeg' in formats:
    248         jpg_formatter.for_type(Figure, lambda fig: print_figure(fig, 'jpg', **kwargs))

/opt/anaconda3/lib/python3.7/site-packages/IPython/core/pylabtools.py in retina_figure(fig, **kwargs)
    134 def retina_figure(fig, **kwargs):
    135     """format a figure as a pixel-doubled (retina) PNG"""
--> 136     pngdata = print_figure(fig, fmt='retina', **kwargs)
    137     # Make sure that retina_figure acts just like print_figure and returns
    138     # None when the figure is empty.

/opt/anaconda3/lib/python3.7/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, pad_inches, bbox_extra_artists, backend, **kwargs)
   2259                         orientation=orientation,
   2260                         bbox_inches_restore=_bbox_inches_restore,
-> 2261                         **kwargs)
   2262             finally:
   2263                 if bbox_inches and restore_bbox:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/backend_bases.py in wrapper(*args, **kwargs)
   1667             kwargs.pop(arg)
   1668 
-> 1669         return func(*args, **kwargs)
   1670 
   1671     return wrapper

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args)
    506             *metadata*, including the default 'Software' key.
    507         """
--> 508         FigureCanvasAgg.draw(self)
    509         mpl.image.imsave(
    510             filename_or_obj, self.buffer_rgba(), format="png", origin="upper",

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    404              (self.toolbar._wait_cursor_for_draw_cm() if self.toolbar
    405               else nullcontext()):
--> 406             self.figure.draw(self.renderer)
    407             # A GUI class may be need to update a window using this draw, so
    408             # don't forget to call the superclass.

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     72     @wraps(draw)
     73     def draw_wrapper(artist, renderer, *args, **kwargs):
---> 74         result = draw(artist, renderer, *args, **kwargs)
     75         if renderer._rasterizing:
     76             renderer.stop_rasterizing()

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     49                 renderer.start_filter()
     50 
---> 51             return draw(artist, renderer, *args, **kwargs)
     52         finally:
     53             if artist.get_agg_filter() is not None:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/figure.py in draw(self, renderer)
   2789             self.patch.draw(renderer)
   2790             mimage._draw_list_compositing_images(
-> 2791                 renderer, self, artists, self.suppressComposite)
   2792 
   2793             for sfig in self.subfigs:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    130     if not_composite or not has_images:
    131         for a in artists:
--> 132             a.draw(renderer)
    133     else:
    134         # Composite any adjacent images together

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     49                 renderer.start_filter()
     50 
---> 51             return draw(artist, renderer, *args, **kwargs)
     52         finally:
     53             if artist.get_agg_filter() is not None:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/_api/deprecation.py in wrapper(*inner_args, **inner_kwargs)
    429                          else deprecation_addendum,
    430                 **kwargs)
--> 431         return func(*inner_args, **inner_kwargs)
    432 
    433     return wrapper

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2919             renderer.stop_rasterizing()
   2920 
-> 2921         mimage._draw_list_compositing_images(renderer, self, artists)
   2922 
   2923         renderer.close_group('axes')

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    130     if not_composite or not has_images:
    131         for a in artists:
--> 132             a.draw(renderer)
    133     else:
    134         # Composite any adjacent images together

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     49                 renderer.start_filter()
     50 
---> 51             return draw(artist, renderer, *args, **kwargs)
     52         finally:
     53             if artist.get_agg_filter() is not None:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/collections.py in draw(self, renderer)
   1010     def draw(self, renderer):
   1011         self.set_sizes(self._sizes, self.figure.dpi)
-> 1012         super().draw(renderer)
   1013 
   1014 

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     49                 renderer.start_filter()
     50 
---> 51             return draw(artist, renderer, *args, **kwargs)
     52         finally:
     53             if artist.get_agg_filter() is not None:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/collections.py in draw(self, renderer)
    406             renderer.draw_markers(
    407                 gc, paths[0], combined_transform.frozen(),
--> 408                 mpath.Path(offsets), transOffset, tuple(facecolors[0]))
    409         else:
    410             renderer.draw_path_collection(

TypeError: must be real number, not str
<Figure size 360x360 with 1 Axes>
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-23-cb00f7dac148> in <module>
     26             edgecolors="red")
     27 plt.show()
---> 28 fig.savefig(f'./plot_fig/{date}_{fold}.png')
     29 
     30 models.append(model)

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/figure.py in savefig(self, fname, transparent, **kwargs)
   3013                 patch.set_edgecolor('none')
   3014 
-> 3015         self.canvas.print_figure(fname, **kwargs)
   3016 
   3017         if transparent:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, pad_inches, bbox_extra_artists, backend, **kwargs)
   2259                         orientation=orientation,
   2260                         bbox_inches_restore=_bbox_inches_restore,
-> 2261                         **kwargs)
   2262             finally:
   2263                 if bbox_inches and restore_bbox:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/backend_bases.py in wrapper(*args, **kwargs)
   1667             kwargs.pop(arg)
   1668 
-> 1669         return func(*args, **kwargs)
   1670 
   1671     return wrapper

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args)
    506             *metadata*, including the default 'Software' key.
    507         """
--> 508         FigureCanvasAgg.draw(self)
    509         mpl.image.imsave(
    510             filename_or_obj, self.buffer_rgba(), format="png", origin="upper",

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    404              (self.toolbar._wait_cursor_for_draw_cm() if self.toolbar
    405               else nullcontext()):
--> 406             self.figure.draw(self.renderer)
    407             # A GUI class may be need to update a window using this draw, so
    408             # don't forget to call the superclass.

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     72     @wraps(draw)
     73     def draw_wrapper(artist, renderer, *args, **kwargs):
---> 74         result = draw(artist, renderer, *args, **kwargs)
     75         if renderer._rasterizing:
     76             renderer.stop_rasterizing()

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     49                 renderer.start_filter()
     50 
---> 51             return draw(artist, renderer, *args, **kwargs)
     52         finally:
     53             if artist.get_agg_filter() is not None:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/figure.py in draw(self, renderer)
   2789             self.patch.draw(renderer)
   2790             mimage._draw_list_compositing_images(
-> 2791                 renderer, self, artists, self.suppressComposite)
   2792 
   2793             for sfig in self.subfigs:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    130     if not_composite or not has_images:
    131         for a in artists:
--> 132             a.draw(renderer)
    133     else:
    134         # Composite any adjacent images together

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     49                 renderer.start_filter()
     50 
---> 51             return draw(artist, renderer, *args, **kwargs)
     52         finally:
     53             if artist.get_agg_filter() is not None:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/_api/deprecation.py in wrapper(*inner_args, **inner_kwargs)
    429                          else deprecation_addendum,
    430                 **kwargs)
--> 431         return func(*inner_args, **inner_kwargs)
    432 
    433     return wrapper

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2919             renderer.stop_rasterizing()
   2920 
-> 2921         mimage._draw_list_compositing_images(renderer, self, artists)
   2922 
   2923         renderer.close_group('axes')

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    130     if not_composite or not has_images:
    131         for a in artists:
--> 132             a.draw(renderer)
    133     else:
    134         # Composite any adjacent images together

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     49                 renderer.start_filter()
     50 
---> 51             return draw(artist, renderer, *args, **kwargs)
     52         finally:
     53             if artist.get_agg_filter() is not None:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/collections.py in draw(self, renderer)
   1010     def draw(self, renderer):
   1011         self.set_sizes(self._sizes, self.figure.dpi)
-> 1012         super().draw(renderer)
   1013 
   1014 

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     49                 renderer.start_filter()
     50 
---> 51             return draw(artist, renderer, *args, **kwargs)
     52         finally:
     53             if artist.get_agg_filter() is not None:

/opt/anaconda3/lib/python3.7/site-packages/matplotlib/collections.py in draw(self, renderer)
    406             renderer.draw_markers(
    407                 gc, paths[0], combined_transform.frozen(),
--> 408                 mpath.Path(offsets), transOffset, tuple(facecolors[0]))
    409         else:
    410             renderer.draw_path_collection(

TypeError: must be real number, not str
```

### 該当のコード

```

fig = plt.figure(figsize=(5, 5))
plt.xlim([0, 2])
plt.ylim([0, 2])

plt.xlabel("true")
plt.ylabel("pred")
plt.scatter(trues, preds, s=400, c="pink", alpha=0.5, linewidths="2",
            edgecolors="red")
plt.show()

```

### 解決法
 linewidths="2"　を
 linewidths=2　に変更