Tokenize and Lemmatize text

#!/usr/local/bin/python3
# -*- coding: utf-8 -*-

import nltk
import requests

file = open("myfile.txt", "r")
obsah = file.read()

print(obsah)
print("############")

def lemmatize(word):
    word=str(word).encode(encoding='utf-8')
    url = 'https://my.server.cz:9200/test_index/_analyze?analyzer=lematizer_custom'
    r = requests.post(url, auth=('username', 'password'), timeout=(3, 10), data=word)
    data = r.json()
    lemma = data['tokens'][0]['token'] # Consider lemmatizing whole sentences, without number but iterating in result.
    return lemma

tokens = nltk.word_tokenize(obsah)
print(tokens)
print("\n")

for token in tokens :
    try:
        print(token, " ", lemmatize(token))

    except:
        print("bad token")