Merge pull request #133 from EleutherAI/fazz/refactor-task-coqa

CoQa Task Initial Implementation

lm_eval/models/gpt2.py

@@ -60,7 +60,7 @@ class GPT2LM(LM):
         for context, until in tqdm(requests):
             if isinstance(until, str): until = [until]
 
-            context_enc = torch.tensor([self.tokenizer.encode(context)]).to(self.device)
+            context_enc = torch.tensor([self.tokenizer.encode(context)[self.MAX_GEN_TOKS - 1024:]]).to(self.device)
 
             primary_until, = self.tokenizer.encode(until[0])
 

lm_eval/tasks/__init__.py

@@ -5,6 +5,7 @@ import sacrebleu
 from . import superglue
 from . import glue
 from . import arc
+from . import coqa
 from . import race
 from . import webqs
 from . import anli
@@ -81,7 +82,7 @@ TASK_REGISTRY = {
     "wsc": superglue.SGWinogradSchemaChallenge,
     
     # Order by benchmark/genre?
-
+    "coqa": coqa.CoQA,
     "lambada": lambada.LAMBADA,
     "piqa": piqa.PiQA,
 

lm_eval/tasks/coqa.py

-# REMINDER: this code needs to be rewritten for the new framework. Remove this comment when the code is fully converted.
-
+import os
 import json
-import random
-from lm_eval.base import Task
+from lm_eval.base import Task, rf, mean
 from ..utils import sh
-
+from itertools import zip_longest
+import transformers.data.metrics.squad_metrics as squad_metrics
+import collections
+import datasets
+import numpy as np
+from lm_eval.base import rf, mean
+from . common import HFTask
+from tqdm import tqdm
+import string, re
 
 class CoQA(Task):
-    def __init__(self):
-        self.download()
+
     def download(self):
-        #TODO: don't download if files already there
-        sh("""
-            mkdir -p data/coqa 
-            wget http://downloads.cs.stanford.edu/nlp/data/coqa/coqa-train-v1.0.json -O data/coqa/coqa-train-v1.0.json
-            wget http://downloads.cs.stanford.edu/nlp/data/coqa/coqa-dev-v1.0.json -O data/coqa/coqa-dev-v1.0.json
-            """)
+        coqa_train_filepath = 'data/coqa/coqa-train-v1.0.json'
+        coqa_dev_filepath = 'data/coqa/coqa-dev-v1.0.json'
+
+        sh ("""mkdir -p data/coqa""")
+        if not os.path.exists(coqa_train_filepath):
+            sh ("""wget http://downloads.cs.stanford.edu/nlp/data/coqa/coqa-train-v1.0.json -O """ + coqa_train_filepath)
+        if not os.path.exists(coqa_dev_filepath):
+            sh ("""wget http://downloads.cs.stanford.edu/nlp/data/coqa/coqa-dev-v1.0.json -O """ + coqa_dev_filepath)
 
     def has_training_docs(self):
         return True
@@ -36,16 +43,71 @@ class CoQA(Task):
         pass
     
     def fewshot_description(self):
-        # TODO: figure out description
-        return ""
+        return "Given a passage and a conversation so far, answer the next question in the conversation."
     
     def doc_to_text(self, doc):
-        # TODO: implement.
-        raise NotImplementedError('doc_to_text not implemented')
-
-    def doc_to_target(self, doc):
-        # TODO: implement.
-        raise NotImplementedError('doc_to_target not implemented')
+        # Given a passage p, the conversation history {q1, a1, . . . qi−1, ai−1} 
+        # and a question qi, the task is to predict the answer ai
+        doc_text = doc["story"] + '\n\n'
+        for (q, a) in zip_longest(doc["questions"], doc["answers"][:-1]):   # omit target answer ai
+            question = f"Q: {q['input_text']}" + '\n\n'
+            answer = f"A: {a['input_text']}" + '\n\n' if a is not None else "A:"
+            doc_text += question + answer
+        return doc_text
+        
+    @classmethod
+    def get_answers(cls, doc, turn_id):
+        # Returns unique answers and valid alternatives (Some questions in CoQA have multiple valid answers).
+        answers = []
+        answer_forturn = doc["answers"][turn_id - 1]["input_text"]
+        answers.append(answer_forturn)
+        
+        additional_answers = doc.get("additional_answers")
+        if additional_answers:
+            for key in additional_answers:
+                additional_answer_for_turn = additional_answers[key][turn_id - 1]["input_text"]
+                if additional_answer_for_turn.lower() not in map(str.lower, answers):
+                    answers.append(additional_answer_for_turn)
+        return answers
+    
+    @classmethod
+    def get_answer_choice(self, raw_text):
+        # Function maps answers to CoQA answer categories
+        # ~ 1/5 of the CoQA answers are Yes/No 
+        # ~ 2/3 of the CoQA answers are span-based
+        # (answers overlap with the passage ignoring punctuation and case mismatch)
+        if raw_text == "unknown":
+            return '0'
+        if squad_metrics.normalize_answer(raw_text) == "yes":
+            return '1'
+        if squad_metrics.normalize_answer(raw_text) == "no":
+            return '2'
+        return '3' # Not a yes/no question
+
+    @staticmethod
+    def compute_scores(gold_list, pred):
+        # tests for exact match and on the normalised answer (compute_exact)
+        # test for overlap (compute_f1)
+        f1_sum = 0.0
+        em_sum = 0.0
+        if len(gold_list) > 1:
+            for i in range(len(gold_list)):
+                gold_answers = gold_list[0:i] + gold_list[i + 1:]
+                # predictions compared against (n) golds and take maximum
+                em_sum += max(squad_metrics.compute_exact(a, pred) for a in gold_answers)
+                f1_sum += max(squad_metrics.compute_f1(a, pred) for a in gold_answers)
+        else:
+            em_sum += max(squad_metrics.compute_exact(a, pred) for a in gold_list)
+            f1_sum += max(squad_metrics.compute_f1(a, pred) for a in gold_list)
+
+        return {'em': em_sum / max(1, len(gold_list)), 'f1': f1_sum / max(1, len(gold_list))}
+
+    def doc_to_target(self, doc, turnid=None):
+        # Default to prediction of last turn.
+        if turnid is None:
+            turnid = len(doc["questions"])
+        raw_text = doc['answers'][turnid - 1]["input_text"]
+        return " " + raw_text
 
     def construct_requests(self, doc, ctx):
         """ Uses RequestFactory to construct Requests and returns an iterable of 
@@ -58,8 +120,8 @@ class CoQA(Task):
             language description, as well as the few shot examples, and the question
             part of the document for `doc`. 
         """
-        # TODO: implement evaluation.
-        raise NotImplementedError('Evaluation not implemented')
+        cont_request = rf.greedy_until(ctx, ['\n'])
+        return cont_request
 
     def process_results(self, doc, results):
         """Take a single document and the LM results and evaluates, returning a 
@@ -71,23 +133,25 @@ class CoQA(Task):
         :param results:
             The results of the requests created in construct_requests.
         """
-        # TODO: implement evaluation.
-        raise NotImplementedError('Evaluation not implemented')
+        turn_id = len(doc["questions"])
+        gold_list = self.get_answers(doc, turn_id)
+        pred = results[0]
 
-    def aggregation(self):
-        """
-        :returns: {str: [float] -> float}
-            A dictionary where keys are the names of submetrics and values are 
-            functions that aggregate a list of metrics
-        """
-        # TODO: implement evaluation.
-        raise NotImplementedError('Evaluation not implemented')
+        scores = self.compute_scores(gold_list, pred)
+
+        return {
+            "f1": scores['f1'],
+            "em": scores['em'],
+        }
 
     def higher_is_better(self):
-        """
-        :returns: {str: bool}
-            A dictionary where keys are the names of submetrics and values are 
-            whether a higher value of the submetric is better
-        """
-        # TODO: implement evaluation.
-        raise NotImplementedError('Evaluation not implemented')
+        return {
+            "f1": True,
+            "em": True,
+        }
+
+    def aggregation(self):
+        return {
+            "f1": mean,
+            "em": mean,
+        }

tests/test_tasks.py

@@ -76,6 +76,9 @@ def test_documents_and_requests(taskname, Task):
 
             reqs = task.construct_requests(doc, txt)
             
+            # construct_requests can return just one request
+            if not isinstance(reqs, (list, tuple)): reqs = [reqs]
+
             # todo: mock lm after refactoring evaluator.py to not be a mess
             for req in reqs:
                 assert isinstance(req, base.Request)