Matplotlib: panel label out of the box, above the ylabel

Question

I have been using matplotlib for all my publication-use figures, and one question is: how to I place the panel labels that is out of the box? The tutorial is shown here, with the code and result:

import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure()
for i, label in enumerate(('A', 'B', 'C', 'D')):
    ax = fig.add_subplot(2,2,i+1)
    ax.text(0.05, 0.95, label, transform=ax.transAxes,
      fontsize=16, fontweight='bold', va='top')

plt.show()

But the panel label is only at the corner of the bounding box, not out side of the box and above the y axis label (which is the usual way), like this:

Any input would be appreciated. Thanks!

Answer 1

values outside of [0, 1] are valid.

import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure()
for i, label in enumerate(('A', 'B', 'C', 'D')):
    ax = fig.add_subplot(2,2,i+1)
    ax.text(-0.1, 1.15, label, transform=ax.transAxes,
      fontsize=16, fontweight='bold', va='top', ha='right')

plt.show()