如何在python中的txt文件中保存解析树

Question

I am having a problem whenever I try to save a parse tree which is generated from some set of rules which I have specified. all I want to save that parse tree in a new text file. when I do this it creates a new text file but it is empty and my code gives an error

'charmap' codec can't encode characters in position 12-18: character maps to

here is my code

sen = "Heyy Jack whats up"
sent = word_tokenize(sen)
gram = ("""
S -> NP VP
NP -> NU | N N
VP -> NP NP
""")
grammar1 = nltk.cfg.fromstring(gram)
sr_parser = nltk.RecursiveDescentParser(grammar1)
for tree in sr_parser.parse(sent):    
    print(tree)
    values = tree
    with open("new.txt", "w") as output: ## creates new file but empty
        output.write(str(values))

Answer 1

Try using utf-8 encding:

with open("new.txt", "w", encoding='utf-8') as output: ## creates new file but empty
        output.write(str(values))

You can also use io for python 2 backward compatibility:

import io
with io.open("new.txt", "w", encoding='utf-8') as output: ## creates new file but empty
    output.write(str(values))