'''Illustrate problem with writable cache in LazySubsequence'''

from nltk.corpus import brown
import nltk, sys

data = brown.tagged_sents(categories='news', tagset='universal')
train_data=data[:1000]
y=train_data[0]
print('initial:',y==train_data[0],train_data[0][:2])
train_data[0].insert(0,('<s>','<s>'))
print('modified:',y==train_data[0],train_data[0][:2])
z=len([s for s in train_data])
print('post-view:',y==train_data[0],train_data[0][:2])

print("\nnltk: %s\npython: %s"%(nltk.version_info,sys.version))