Python 将打印print的内容保存到日志文件

import sys
import datetime

class Logger(object):
    def __init__(self, filename, stream=sys.stdout):
        self.terminal = stream
        self.log = open(filename, 'w',encoding='utf-8')
        self.previousMsg = None
        sys.stdout = self

    def write(self, message):
        if self.previousMsg == None or "\n" in self.previousMsg:
            topMsg = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S") + " : "
            self.terminal.write(topMsg) # 显示前端
            self.log.write(topMsg) # 输出日志

        if isinstance(message, str):
            self.previousMsg = message
        if self.previousMsg == None:
            self.previousMsg = ""

        self.terminal.write(message)
        self.log.write(message)
        self.log.flush() # 刷新缓存区，即将缓存区的内容立即写入到文件(否则就会运行完程序在写入)

    def flush(self):
        pass

# 文件名字（如果之前不存在，则会在程序运行后自动创建，如果存在，则打开会实时显示）
fileName = datetime.datetime.now().strftime("%Y-%m-%d-%H-%M-%S")
sys.stdout = Logger(fileName+".log") # 记录正常的 print 信息
sys.stderr = Logger(fileName+".log") # 记录 traceback 信息

if __name__ == '__main__':
    import time
    for i in range(100):
        print(i)
        time.sleep(1)
        if i == 10:
            # i/0
            break