python 2.7极地函数

Question

当我运行以下程序时，显示错误。请帮我改正。

from pylab import *
polar(pi/2,5,'g*')
show()

错误：

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Python27\lib\lib-tk\Tkinter.py", line 1541, in __call__
    return self.func(*args)
  File "C:\Python27\lib\site-packages\matplotlib\backends\backend_tkagg.py", line 236, in resize
    self.show()
  File "C:\Python27\lib\site-packages\matplotlib\backends\backend_tkagg.py", line 239, in draw
    FigureCanvasAgg.draw(self)
  File "C:\Python27\lib\site-packages\matplotlib\backends\backend_agg.py", line 401, in draw
    self.figure.draw(self.renderer)
  File "C:\Python27\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "C:\Python27\lib\site-packages\matplotlib\figure.py", line 884, in draw
    func(*args)
  File "C:\Python27\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "C:\Python27\lib\site-packages\matplotlib\axes.py", line 1983, in draw
    a.draw(renderer)
  File "C:\Python27\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "C:\Python27\lib\site-packages\matplotlib\axis.py", line 1040, in draw
    tick.draw(renderer)
  File "C:\Python27\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)

Answer 1

尝试import math，然后使用polar(math.pi/2,5,'g*') 你也可以import numpy as np 和使用np.pi