GeezerVison

import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt
import numpy as np
import plotly.tools as tls

x = np.linspace(-3, 3, 30)
X, Y = np.meshgrid(x, x)
t = np.linspace(0, 2 * np.pi, 50)

cases = {
    "violinplot":   lambda: plt.violinplot(np.random.randn(100, 3)),
    "pcolor":       lambda: plt.pcolor(X, Y, np.sin(X) * np.cos(Y)),
    "eventplot":    lambda: plt.eventplot([np.random.randn(20) for _ in range(5)]),
    "stackplot":    lambda: plt.stackplot(np.arange(10), np.random.rand(10), np.random.rand(10), np.random.rand(10)),
    "fill_between": lambda: plt.fill_between(t, np.sin(t), np.cos(t)),
    "stem":         lambda: plt.stem(np.linspace(0, 2 * np.pi, 20), np.sin(np.linspace(0, 2 * np.pi, 20))),
}

for name, build in cases.items():
    fig, ax = plt.subplots()
    build()
    fig.savefig(f"{name}_mpl.png")

    p = tls.mpl_to_plotly(fig)   # 0 traces for all of these before the fix (except stem, which had some traces)
    p.write_image(f"{name}_plotly.png")

    print(f"{name:13s} -> {len(p.data)} traces")