[FIXED] Matplotlib add a default watermark

Issue

I'm using matplotlib for work and company policy is to include a watermark on every plot we make. Is there a way to set matplotlib to do this by default?

I'm currently passing each Axes object into a helper function which adds the watermark in the bottom left corner.

import matplotlib.pyplot as plt

def add_watermark(ax):
    ax.text(ax.get_xlim()[0] + 0.1, 
            ax.get_ylim()[0] + 0.1, 
            "<Company Name>", 
            alpha=0.5)

fig, ax = plt.subplots(1, 1)
x = np.fromiter((np.random.uniform() for _ in range(100)), dtype=np.float32)
y = np.fromiter((np.random.uniform() for _ in range(100)), dtype=np.float32)
ax.scatter(x, y)
add_watermark(ax)

I would like to modify the default behavior of matplotlib so that I don't have to pass each axes instance into a helper function.

Solution

You may easily subclass and monkey-patch the default axes. So create a file matplotlib_company.py like this

import matplotlib.axes
from matplotlib.offsetbox import AnchoredText

class MyAxes(matplotlib.axes.Axes):
    def __init__(self, *args, **kwargs):

        super().__init__(*args, **kwargs)
        ab = AnchoredText("<company name>", loc="lower left", frameon=False,
                          borderpad=0, prop=dict(alpha=0.5))
        ab.set_zorder(0)
        self.add_artist(ab)

matplotlib.axes.Axes = MyAxes

Then import it everywhere you need it. I.e. the following

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

creates

Answered By - ImportanceOfBeingErnest