python：TypeError：函数最多需要4个参数（给定6个）

Question

from PIL import Image
im = Image.open("9-6.jpg")
im.show()
im.save("test.png")

堆栈跟踪：

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>

  File "/usr/lib64/python2.7/site-packages/PIL/Image.py", line 1477, in save
    save_handler(self, fp, filename)

  File "/usr/lib64/python2.7/site-packages/PIL/PngImagePlugin.py", line 608, in _save

    ImageFile._save(im, _idat(fp, chunk), [("zip", (0,0)+im.size, 0, rawmode)])

  File "/usr/lib64/python2.7/site-packages/PIL/ImageFile.py", line 456, in _save
    e = Image._getencoder(im.mode, e, a, im.encoderconfig)

  File "/usr/lib64/python2.7/site-packages/PIL/Image.py", line 395, in _getencoder

    return encoder(mode, *args + extra)

TypeError: function takes at most 4 arguments (6 given)