Unable to do Pos_tag to extract

Question

For a NLP task, my code is

for i in df['token'][1]: wL=nltk.pos_tag(i)

Error - "Output exceeds the size limit" while calculating wL.

Why am I getting the error instead of the Part of speech in Line 2? How do I extract the verb or noun? The error further says that it is a 'LookUp Error'.

I also downloaded spacy's en_core_web_sm and tried to do nlp as -

nlp=spacy.load('') doc=nlp(text) # Here I get error - IndexError - tuple index out of range