from matplotlib import pyplot as plt

plt.rcParams.update({
    'font.family': 'sans-serif',
    'font.sans-serif': ['Times New Roman'],
    })
losses= []
val_loss = []


with open('epoch_loss.txt', encoding='utf-8') as f:
    for line in f:
        line = line.strip('\n')
        print(line)
        losses.append(float(line))
        num=len(losses)
        iters = range(num)
with open('epoch_val_loss.txt', encoding='utf-8') as f:
    for line in f:
        line = line.strip('\n')
        val_loss.append(float(line))


plt.figure()
plt.plot(iters, losses, 'red', linewidth=2, label='train loss')
plt.plot(iters, val_loss, 'blue', linewidth=2, label='val loss')
print(iters)
print(losses)
plt.grid(True)
plt.xlabel('Epoch')
plt.ylabel('Loss')
plt.title('A Loss Curve')
plt.legend(loc="upper right")

plt.savefig("epoch_loss.png")
plt.savefig( "epoch_loss.svg")  #矢量图不失真

plt.cla()
plt.close("all")

效果图如下