python模拟tail -f监控文件的变动

py_tail.py

# 方法1
with open('/tmp/track-this') as f:
  while True:
    line = f.readline()
    if line:
      print line
      
# 方法2
import time
def follow(thefile):
    thefile.seek(0,2)
    while True:
        line = thefile.readline()
        if not line:
            time.sleep(0.1)
            continue
        yield line

if __name__ == '__main__':
    logfile = open("run/foo/access-log","r")
    loglines = follow(logfile)
    for line in loglines:
        print line,