Traceback (most recent call last):
  File "<string>", line 4, in <module>
  File "matplotlib/lib/matplotlib/pyplot.py", line 2452, in boxplot
    is not None else {}))
  File "matplotlib/lib/matplotlib/__init__.py", line 1517, in inner
    return func(ax, *map(sanitize_sequence, args), **kwargs)
  File "matplotlib/lib/matplotlib/axes/_axes.py", line 3521, in boxplot
    labels=labels, autorange=autorange)
  File "matplotlib/lib/matplotlib/cbook/__init__.py", line 1243, in boxplot_stats
    X = _reshape_2D(X, "X")
  File "matplotlib/lib/matplotlib/cbook/__init__.py", line 1419, in _reshape_2D
    if X.ndim == 1 and not isinstance(X[0], collections.abc.Iterable):
IndexError: index 0 is out of bounds for axis 0 with size 0