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verl/utils/reward_score/gsm8k.py

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+# Copyright 2024 Bytedance Ltd. and/or its affiliates
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import re
+
+
+def extract_solution(solution_str, method='strict'):
+    assert method in ['strict', 'flexible']
+
+    if method == 'strict':
+        # this also tests the formatting of the model
+        solution = re.search("#### (\\-?[0-9\\.\\,]+)", solution_str)
+        if solution is None:
+            final_answer = None
+        else:
+            final_answer = solution.group(0)
+            final_answer = final_answer.split('#### ')[1].replace(',', '').replace('$', '')
+    elif method == 'flexible':
+        answer = re.findall("(\\-?[0-9\\.\\,]+)", solution_str)
+        final_answer = None
+        if len(answer) == 0:
+            # no reward is there is no answer
+            pass
+        else:
+            invalid_str = ['', '.']
+            # find the last number that is not '.'
+            for final_answer in reversed(answer):
+                if final_answer not in invalid_str:
+                    break
+    return final_answer
+
+
+def compute_score(solution_str, ground_truth, method='strict', format_score=0., score=1.):
+    """The scoring function for GSM8k.
+
+    Reference: Trung, Luong, et al. "Reft: Reasoning with reinforced fine-tuning." Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2024.
+
+    Args:
+        solution_str: the solution text
+        ground_truth: the ground truth
+        method: the method to extract the solution, choices are 'strict' and 'flexible'
+        format_score: the score for the format
+        score: the score for the correct answer
+    """
+    answer = extract_solution(solution_str=solution_str, method=method)
+    if answer is None:
+        return 0
+    else:
+        if answer == ground_truth:
+            return score
+        else:
+            return format_score