matplotlib eats all memory when saving fig matplotlib eats all memory when saving fig

fig = plt.figure(num=1, clear=True)

for i in tqdm(range(55238, len(df)-40)):

    df_tmp = df.iloc[i:i+30]

    name = f’data/{i+30+1}’

    generate_picture(df_tmp, name, fig)

    gc.collect()import matplotlib.pyplot as plt

import numpy as np
A = np.arange(1,5)

B = A**2
cnt=0

while(1):

    cnt = cnt+1

    print(“########### test %d ###########” % cnt)
    # here is the trick:

    # set the figure a ‘num’ to prevent from re-malloc of a figure in the next loop

    # and set “clear=True” to make the figure clear

    # I never use plt.close() to kill the figure, because I found it doesn’t work.

    # Only one figure is allocated, which can be self-released when the program quits.

    # Before: 6000 times calling of plt.figure() ~ about 1.6GB of memory leak

    # Now: the memory keeps in a stable level

    fig = plt.figure(num=1, clear=True)

    ax = fig.add_subplot()
    # alternatively use an other function in one line

    # fig, ax = plt.subplots(num=1,clear=True)
    ax.plot(A,B)

    ax.plot(B,A)
    # Here add the functions you need

    # plt.show()

    fig.savefig(‘%d.png’ % cnt)