python3 编辑文件的两种方式

mode1:
with open('a.txt',mode='rt',encoding='utf-8') as f:
    res = f.read()
    data = res.replace('aaa','111')
    print(data)
with open('a.txt',mode='wt',encoding='utf-8') as f1:
    f1.write(data)

mode2:
with open('a.txt',mode='rt',encoding='utf-8') as f,open('.a.txt.swap',mode='wt',encoding='utf-8') as f1:
    for line in f:
        f1.write(line.replace('aaa','111'))
os.remove('a.txt')
os.rename('.a.txt.swap','a.txt')