无法从 libpgm package 读取文件

Question

I installed libpgm for my jupyter notebook by

pip install libpgm

and then ran several imports as follow

import sys
import json
import libpgm
from libpgm.nodedata import NodeData
from libpgm.graphskeleton import GraphSkeleton
from libpgm.hybayesiannetwork import HyBayesianNetwork

I got an error

Traceback (most recent call last):

  File "C:\Users\19413\conda\lib\site-packages\IPython\core\interactiveshell.py", line 3343, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)

  File "<ipython-input-7-80536a116c64>", line 4, in <module>
    from libpgm.nodedata import NodeData

  File "C:\Users\19413\conda\lib\site-packages\libpgm\nodedata.py", line 91
    print "Error: NodeData did not recognize input file format."
          ^
SyntaxError: Missing parentheses in call to 'print'. Did you mean print("Error: NodeData did not recognize input file format.")?

Does anyone know what caused the error?

Thanks very much for your help

Answer 1

Well, the last line of your error report says exactly what caused the error:

Missing parentheses in call to 'print'. Did you mean print("Error: NodeData did not recognize input file format.")?

Unlike Python 2, Python 3 requires all print statements to be enclosed in parentheses. I'm not familiar with the libpgm library but it seems to me that this has been fixed five years ago . Make sure that you use the newest version of this library or run your code with Python 2 instead.