我将使用 matplotlibspines中的set_linewidth和set_color参数：
轴线--表示数据区边界的线。

import matplotlib.pyplot as plt

C, W, L, T = "black", 4, 2, 7 # <- adjust here
#Color, Width, Length, Tickness --------------

fig, ax = plt.subplots(figsize=(W, L))
list_of_spines = ["left", "right", "top", "bottom"]

for sp in list_of_spines:
    ax.spines[sp].set_linewidth(T)
    ax.spines[sp].set_color(C)

ax.set_xticks([])
ax.set_yticks([])

plt.show();

输出：

在类似的问题上，您可以使用answer的以下代码

import matplotlib.pyplot as plt
import matplotlib as mpl
plt.rcParams["axes.edgecolor"] = "black"
plt.rcParams["axes.linewidth"] = 2.50
fig = plt.figure(figsize = (4.1, 2.2))
ax = fig.add_subplot(111)

您可以设置图像周围边框的宽度和颜色，如下所示：

from matplotlib import pyplot as plt

# some data for demonstration purposes
import numpy as np
x = np.random.randn(100)

# create figure
fig, ax = plt.subplots()

ax.plot(x)

# set the border width
fig.set_linewidth(10)

# set the border colour (to black in this case)
fig.set_edgecolor("k")

# show the figure
fig.show()

这给出：