输出重定向工具

main主体

import time
import sys
from test.utils import TraceLog


class Server(object):
 def printLog(self):
 print("start server")
 for i in range(10):
 print(i)
 time.sleep(0.1)
 print("end server\n")


if __name__ == '__main__':
 traceLog = TraceLog("main.log")
 traceLog.start()
 sys.stdout = traceLog
 sys.stderr = traceLog
 server = Server()
 server.printLog()


# 每当调用print的时候，底层就是在代用sys.stdout.write(str)
# sys.stdout.write() = traceLog.write()

utils工具

'''
不断记录服务端输入的日志
实现 >> 和 > 功能
'''

import codecs
from threading import Thread, Lock
import os

class TraceLog(Thread):
 def __init__(self, logName):
 # super().__init__() #python3的调用父类的方法，python2用的是super(Class, self).xxx，也是等价于Thread.__init__(self)
 Thread.__init__(self)
 self.logName = logName
 self.lock = Lock()
 self.contexts = []

 def isFile(self):
 if not os.path.exists(self.logName):
 with codecs.open(self.logName, 'w') as f:
 f.write("this log name is: {0}\n".format(self.logName))
 f.write("start log\n")

 def write(self, context):
 self.contexts.append(context)

 def run(self):
 while 1:
 # self.lock.acquire()
 if len(self.contexts) != 0:
 with codecs.open(self.logName, "a") as f:
 for context in self.contexts:
 f.write(context)
 del self.contexts[:] # 注意不能忘记清空
 # self.lock.release()