python绘制lost损失曲线加方差范围的操作方法

import re
import seaborn as sns
import matplotlib.pyplot as plt
import matplotlib.cm as cm
import shutil
import os
sns.set_style('whitegrid')

file_path = 'log.txt'
content = []
with open(file_path, 'r') as f:
    for line in f.readlines():
        line = line.strip('\n')
        content.append(line)
iter = []
totalreward = []
returnavg = []
returnstd = []
for line in content:
    str1 = re.findall('train.+', line)
    v = [float(x) for x in re.findall('-?\d+.?\d+|\d+', str1[0])]
    iter.append(v[0])
    totalreward.append(v[1])
    returnavg.append(v[2])
    returnstd.append(v[3])

color = cm.viridis(0.5)
f, ax = plt.subplots(1,1)
ax.plot(iter, totalreward, color=color)
ax.legend()
ax.set_xlabel('Iteration')
ax.set_ylabel('Return')
exp_dir = 'Plot/'
if not os.path.exists(exp_dir):
    os.makedirs(exp_dir, exist_ok=True)
else:
    os.makedirs(exp_dir, exist_ok=True)
f.savefig(os.path.join('Plot', 'reward' + '.png'), dpi=1000)

color = cm.viridis(0.7)
f, ax = plt.subplots(1,1)
ax.plot(iter, returnavg, color=color)
r1 = list(map(lambda x: x[0]-x[1], zip(returnavg, returnstd)))
r2 = list(map(lambda x: x[0]+x[1], zip(returnavg, returnstd)))
ax.fill_between(iter, r1, r2, color=color, alpha=0.2)
ax.legend()
ax.set_xlabel('Iteration')
ax.set_ylabel('Return')
exp_dir = 'Plot/'
if not os.path.exists(exp_dir):
    os.makedirs(exp_dir, exist_ok=True)
f.savefig(os.path.join('Plot', 'avgreward' + '.png'), dpi=50)