update

tests/test_cer.py

@@ -0,0 +1,93 @@
+"""
+f(a, b) 计算 a -> b 的编辑距离，使用的方法是之前asr榜单的方法
+g(a, b) 计算 a -> b 的编辑距离，使用的是原始的编辑距离计算方法
+test() 是对拍程序
+"""
+
+import random
+import string
+from copy import deepcopy
+from typing import List, Tuple
+
+import Levenshtein
+
+
+def mapping(gt: str, dt: str):
+    return [i for i in gt], [i for i in dt]
+
+
+def token_mapping(
+    tokens_gt: List[str], tokens_dt: List[str]
+) -> Tuple[List[str], List[str]]:
+    arr1 = deepcopy(tokens_gt)
+    arr2 = deepcopy(tokens_dt)
+    operations = Levenshtein.editops(arr1, arr2)
+    for op in operations[::-1]:
+        if op[0] == "insert":
+            arr1.insert(op[1], None)
+        elif op[0] == "delete":
+            arr2.insert(op[2], None)
+    return arr1, arr2
+
+
+def cer(tokens_gt_mapping: List[str], tokens_dt_mapping: List[str]):
+    """输入的是经过编辑距离映射后的两个 token 序列，返回 1-cer, token-cnt"""
+    insert = sum(1 for item in tokens_gt_mapping if item is None)
+    delete = sum(1 for item in tokens_dt_mapping if item is None)
+    equal = sum(
+        1
+        for token_gt, token_dt in zip(tokens_gt_mapping, tokens_dt_mapping)
+        if token_gt == token_dt
+    )
+    replace = len(tokens_gt_mapping) - insert - equal  # - delete
+    return replace, delete, insert
+
+
+def f(a, b):
+    return cer(*token_mapping(*mapping(a, b)))
+
+
+def raw(tokens_gt, tokens_dt):
+    arr1 = deepcopy(tokens_gt)
+    arr2 = deepcopy(tokens_dt)
+    operations = Levenshtein.editops(arr1, arr2)
+    insert = 0
+    delete = 0
+    replace = 0
+    for op in operations:
+        if op[0] == "insert":
+            insert += 1
+        if op[0] == "delete":
+            delete += 1
+        if op[0] == "replace":
+            replace += 1
+    return replace, delete, insert
+
+
+def g(a, b):
+    return raw(*mapping(a, b))
+
+
+def check(a, b):
+    ff = f(a, b)
+    gg = g(a, b)
+    if ff != gg:
+        print(ff, gg)
+    return ff == gg
+
+
+def random_string(length):
+    letters = string.ascii_lowercase
+    return "".join(random.choice(letters) for i in range(length))
+
+
+def test():
+    for _ in range(10000):
+        a = random_string(30)
+        b = random_string(30)
+        if not check(a, b):
+            print(a, b)
+            break
+
+
+test()