matplotlib and Pillow (PIL) incompatible?

Question

I have the following program that does not work if I run:

import tkinter as tk
import matplotlib.pyplot as plt
import numpy as np
from PIL import Image, ImageTk

##MATPLOTLIB STUFF --------------------------------------------
fig, ax = plt.subplots(figsize = (5,5))

x = np.arange(10)
y = np.random.randn(10)

ax.plot(x,y)
fig.savefig('image1.png', bboxtoinches = 'tight')


##PIL STUFF --------------------------------------------------
root = tk.Tk()

graph = ImageTk.PhotoImage(file="image1.png")
w1 = tk.Label(root, image=graph).pack(side='right')

explanation = "A matplotlib plot"
w2 = tk.Label(root, justify=tk.LEFT, padx=10, 
text=explanation).pack(side='left')

root.mainloop()

but DOES work if I delete the matplotlib stuff and run

import tkinter as tk
import matplotlib.pyplot as plt
import numpy as np
from PIL import Image, ImageTk

##PIL STUFF --------------------------------------------------
root = tk.Tk()

graph = ImageTk.PhotoImage(file="image1.png")
w1 = tk.Label(root, image=graph).pack(side='right')

explanation = "A matplotlib plot"
w2 = tk.Label(root, justify=tk.LEFT, padx=10, 
text=explanation).pack(side='left')

root.mainloop()

As a matter of fact, the line that seems to cause the problem is

fig, ax = plt.subplots(figsize = (5,5))

If I do include this line then I get the following error:

Traceback (most recent call last):
  File "proj_1_images.py", line 20, in <module>
    w1 = tk.Label(root, image=graph).pack(side='right')
  File "C:\Users\Luke Polson\AppData\Local\Programs\Python\Python36\lib\tkinter\__init__.py", line 2760, in __init__
    Widget.__init__(self, master, 'label', cnf, kw)
  File "C:\Users\Luke Polson\AppData\Local\Programs\Python\Python36\lib\tkinter\__init__.py", line 2293, in __init__
    (widgetName, self._w) + extra + self._options(cnf))
_tkinter.TclError: image "pyimage10" doesn't exist

Why would matplotlib be causing this error?

Answer 1

代码对我来说运行顺利，您的问题是pyimage10存储在内存中，但是找不到路径，重新启动内核并清除内存中所有已声明的变量将解决此问题。