IndentationError: expected an indented block

[anxin16]

When I run the code in python3,

from pattern3.en import tag
from nltk.corpus import wordnet as wn

# Annotate text tokens with POS tags
def pos_tag_text(text):

def penn_to_wn_tags(pos_tag):
        if pos_tag.startswith('J'):
            return wn.ADJ
        elif pos_tag.startswith('V'):
            return wn.VERB
        elif pos_tag.startswith('N'):
            return wn.NOUN
        elif pos_tag.startswith('R'):
            return wn.ADV
        else:
            return None

tagged_text = tag(text)
    tagged_lower_text = [(word.lower(), penn_to_wn_tags(pos_tag))
                         for word, pos_tag in
                         tagged_text]
    return tagged_lower_text

I got the error message:
File "/Anaconda3/lib/python3.6/site-packages/pattern3/text/tree.py", line 37
except:
^
IndentationError: expected an indented block

[anxin16]

Please check tree.py

[barliant]

There is an empty line after try: in line 36 tree.py, followed by except:

[barliant]

Checking the code of tree.py from pattern, it might look something like this

try:
    from itertools import chain
    from itertools import izip
except:
    izip = zip  # Python 3

Instead of

from itertools import chain
try:
    
except:
    izip = zip  # Python 3