python在控制台输出进度条的方法

|#############################---------------------|
59 percent done

class ProgressBar():
  def __init__(self, width=50):
    self.pointer = 0
    self.width = width
  def __call__(self,x):
     # x in percent
     self.pointer = int(self.width*(x/100.0))
     return "|" + "#"*self.pointer + "-"*(self.width-self.pointer)+\
        "|\n %d percent done" % int(x)

if __name__ == '__main__':
  import time, os
  pb = ProgressBar()
  for i in range(101):
    os.system('clear')
    print pb(i)
    time.sleep(0.1)