seeking Help for Comp Ling Methods Homework Assignment: Bigrams

• 

  Posted by Shani Tzoref on October 17, 2019 at 7:19 pm

  Hi, group.
  I would greatly appreciate some debugging help, related to a homework assignment in the Comp Ling Methods I course.
  The assigned task was to define a function to list bigrams of a list of strings.
  Feeling stuck in the assignment, I decided to try something simpler:  rather than defining a function, I tried to create a list of bigrams for a specific list.
  For the following list: LSD = [“Lucy”, “in”, “the”, “sky”, “with”, “diamonds”]
  I want to produce code to give me a list of word pairs:
  [[“Lucy”, “in”], [“in”, “the”], [“the”, “sky”], [“sky”, “with”], [“with”, “diamonds”]]

  My attempted code gives me only the strings in the original list, setting them within individual lists, but not as pairs.  I’ve attached a PDF of my Jupyter notebook, and will also paste the failed code here:

  LSD = [“Lucy”, “in”, “the”, “sky”, “with”, “diamonds”]
  #produce list of bigrams

  pairs = []
  for x in range(len(LSD)):
  pair = LSD[x:x +1]
  pairs += [pair]

  print(pairs)

  The result I get is:

  [['Lucy'], ['in'], ['the'], ['sky'], ['with'], ['diamonds']]

  Thanks,
  Shani

   

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• Stephen Zweibel

  Member

  October 18, 2019 at 12:22 pm

  Hi Shani,
  You’re close. Take a look at this line:
  pair = LSD[x:x +1]
  You want to grab the next word on the list, but x + 1 won’t do that. you have to refer to the list and get the index of the word you want. And, in order to refer to the index in a for loop, you have to use ‘enumerate’. So here’s what I got:

  pairs = []
  for index, word in enumerate(LSD):
       try:
            next_word = LSD[index+1]
            pairs.append([word, next_word])
       except IndexError:
            pass
  print(pairs)

  I added the ‘try’ clause because otherwise you get an error at the end of the list, when it tried to look for the next word and there isn’t one.

  • This reply was modified 5 years ago by Stephen Zweibel.
  Patrick Smyth, PhD

  Participant

  October 18, 2019 at 12:26 pm

  Hi Shani,

   

  I don’t want to give you too many hints, since I think you’re pretty close to a solution here. But this REPL session might give you an idea of what’s happening:

  https://gist.githubusercontent.com/smythp/f3aa9b9fa8cabd4560a1dc4625c34658/raw/7d609d7e80535e8f37b29275378d3212ec44793a/gistfile1.txt

  Hope that helps a little.

   

  Patrick
  Shani Tzoref

  Member

  October 29, 2019 at 9:51 am

  Thanks for replies!  Sorry I did not respond sooner.  I became overwhelmed and pre-occupied with some personal stuff– including the birth of my first granddaughter last week.  I ended up submitting my incomplete code for the assignment. I am trying to reboot my studies now, and hope to try your advice in the coming days.
  In any case, it was really helpful to get support when I was feeling stuck.  And you both seemed to have hit the right register– of advising and guiding, rather than just feeding me an answer.  What a great forum.
  Patrick Smyth, PhD

  Participant

  October 29, 2019 at 7:55 pm

  Congratulations on the birth of your granddaughter!
  Lisa Marie Rhody

  Member

  November 5, 2019 at 7:55 pm

  Congratulations, Shani, on a new grandchild! And glad that you could find
  the help here. It was a fun challenge to watch you all work through. Hoping
  to see more of them!!!!
  Best,
  Lisa

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  Lisa Rhody, Ph.D.
  Deputy Director of Digital Initiatives
  Director, Digital Fellowship Programs
  Director, Digital Humanities Research Institutes
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  lrhody@gc.cuny.edu | @lmrhody