ZeroDivisionError test_phrase_grammar

[L0ittle]

Hi,when I run the test_phrase_grammar.py ,I will get this return like following:

ZeroDivisionError: float division by zero

This is the specific error:

[shawntan]

You may need to obtain the PennTreebank parse trees before running test_phrase_grammar.py

[L0ittle]

You may need to obtain the PennTreebank parse trees before running test_phrase_grammar.py

Thank you a lot. And I thought I have downloaded the PTB like following:

But It seems that these data don't work, I'm confused. Can you tell me whether this file I have download through CSDN is right? And I have no membership in Treebank Official site, what should I do?

[Sunzheng-Hub]

we can get two Parsed subsets of Penn Treebank for free.
http://www.nltk.org/nltk_data/

[JIAZhenZ]

I wonder how can I get a parse tree, hope for answering, thanks

[shawntan]

You'll have to get it from LDC https://catalog.ldc.upenn.edu/LDC99T42