from IPython.display import HTML
import string

def plot_ngram(text, start, end, corpus, smoothing):
    '''
    text: String with the n-gram to be searched. Words must be separated by spaces.
    start: from year
    end: to year
    corpus: corpus to be used (21:Spanish, 15:English, etc. check https://books.google.com/ngrams for more)
    smoothing: number of years to average 
    '''
    text = string.join(text.split(),'+')
    url = ("https://books.google.com/ngrams/graph?content=%s&year_start=%d&year_end=%d&corpus=%d&smoothing=%d"%
          (text, start, end, corpus, smoothing))
    return HTML("<iframe src=%s width=1000 height=650></iframe>"%url)

plot_ngram("esta es una prueba", 1800, 2000, 21, 3)