NLTK dependencies are downloaded during the import phase

[tmiskow]

Unfortunately, NLTK dependencies are downloaded during the import phase, therefore, making it very difficult to configure nltk data paths and download directories beforehand.

I think simply moving the following code to from the top level to the G2p object initialization should solve the issue.

try:
    nltk.data.find('taggers/averaged_perceptron_tagger.zip')
except LookupError:
    nltk.download('averaged_perceptron_tagger')
try:
    nltk.data.find('corpora/cmudict.zip')
except LookupError:
    nltk.download('cmudict')

Maybe we could also provide nltk_data_diretcory as an optional argument and pass it to nltk.download invocations?