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
")


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}
".format(self.logName))
                f.write("start log
")

    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()