ValueError: Unknown artist property

ValueError: Unknown artist property

$ python -c "import matplotlib.pyplot as plt; plt.plot([1,2],[3,4], linewidths=2)"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ValueError: Unknown artist property: linewidths

Why this happens

You used an invalid keyword; e.g., linewidths is for scatter, while plot expects linewidth.

Fix

Use the correct property names for the specific artist.

Wrong code

import matplotlib.pyplot as plt
plt.plot([1,2],[3,4], linewidths=2)

Fixed code

import matplotlib.pyplot as plt
plt.plot([1,2],[3,4], linewidth=2)
plt.show()