diff --git a/egs/aishell/ASR/pruned_transducer_stateless7/export2.py b/egs/aishell/ASR/pruned_transducer_stateless7/export2.py
index 824b619e7..14c826521 100755
--- a/egs/aishell/ASR/pruned_transducer_stateless7/export2.py
+++ b/egs/aishell/ASR/pruned_transducer_stateless7/export2.py
@@ -100,27 +100,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import str2bool
-
-
-def num_tokens(
-    token_table: k2.SymbolTable, disambig_pattern: str = re.compile(r"^#\d+$")
-) -> int:
-    """Return the number of tokens excluding those from
-    disambiguation symbols.
-
-    Caution:
-      0 is not a token ID so it is excluded from the return value.
-    """
-    symbols = token_table.symbols
-    ans = []
-    for s in symbols:
-        if not disambig_pattern.match(s):
-            ans.append(token_table[s])
-    num_tokens = len(ans)
-    if 0 in ans:
-        num_tokens -= 1
-    return num_tokens
+from icefall.utils import str2bool, num_tokens
 
 
 def get_parser():
diff --git a/egs/librispeech/ASR/pruned_transducer_stateless7/export-onnx.py b/egs/librispeech/ASR/pruned_transducer_stateless7/export-onnx.py
index 37597e5be..f799f67f6 100755
--- a/egs/librispeech/ASR/pruned_transducer_stateless7/export-onnx.py
+++ b/egs/librispeech/ASR/pruned_transducer_stateless7/export-onnx.py
@@ -68,7 +68,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import setup_logger, str2bool
+from icefall.utils import setup_logger, str2bool, num_tokens
 
 
 def get_parser():
@@ -160,26 +160,6 @@ def add_meta_data(filename: str, meta_data: Dict[str, str]):
     onnx.save(model, filename)
 
 
-def num_tokens(
-    token_table: k2.SymbolTable, disambig_pattern: str = re.compile(r"^#\d+$")
-) -> int:
-    """Return the number of tokens excluding those from
-    disambiguation symbols.
-
-    Caution:
-      0 is not a token ID so it is excluded from the return value.
-    """
-    symbols = token_table.symbols
-    ans = []
-    for s in symbols:
-        if not disambig_pattern.match(s):
-            ans.append(token_table[s])
-    num_tokens = len(ans)
-    if 0 in ans:
-        num_tokens -= 1
-    return num_tokens
-
-
 class OnnxEncoder(nn.Module):
     """A wrapper for Zipformer and the encoder_proj from the joiner"""
 
diff --git a/egs/librispeech/ASR/pruned_transducer_stateless7/export.py b/egs/librispeech/ASR/pruned_transducer_stateless7/export.py
index b77737a11..d186441fd 100755
--- a/egs/librispeech/ASR/pruned_transducer_stateless7/export.py
+++ b/egs/librispeech/ASR/pruned_transducer_stateless7/export.py
@@ -100,27 +100,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import str2bool
-
-
-def num_tokens(
-    token_table: k2.SymbolTable, disambig_pattern: str = re.compile(r"^#\d+$")
-) -> int:
-    """Return the number of tokens excluding those from
-    disambiguation symbols.
-
-    Caution:
-      0 is not a token ID so it is excluded from the return value.
-    """
-    symbols = token_table.symbols
-    ans = []
-    for s in symbols:
-        if not disambig_pattern.match(s):
-            ans.append(token_table[s])
-    num_tokens = len(ans)
-    if 0 in ans:
-        num_tokens -= 1
-    return num_tokens
+from icefall.utils import str2bool, num_tokens
 
 
 def get_parser():
diff --git a/egs/librispeech/ASR/zipformer/export.py b/egs/librispeech/ASR/zipformer/export.py
index 4a48d5bad..dd1d21ef4 100755
--- a/egs/librispeech/ASR/zipformer/export.py
+++ b/egs/librispeech/ASR/zipformer/export.py
@@ -176,27 +176,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import make_pad_mask, str2bool
-
-
-def num_tokens(
-    token_table: k2.SymbolTable, disambig_pattern: str = re.compile(r"^#\d+$")
-) -> int:
-    """Return the number of tokens excluding those from
-    disambiguation symbols.
-
-    Caution:
-      0 is not a token ID so it is excluded from the return value.
-    """
-    symbols = token_table.symbols
-    ans = []
-    for s in symbols:
-        if not disambig_pattern.match(s):
-            ans.append(token_table[s])
-    num_tokens = len(ans)
-    if 0 in ans:
-        num_tokens -= 1
-    return num_tokens
+from icefall.utils import make_pad_mask, str2bool, num_tokens
 
 
 def get_parser():
diff --git a/icefall/utils.py b/icefall/utils.py
index 0feff9dc8..c8d20f5f4 100644
--- a/icefall/utils.py
+++ b/icefall/utils.py
@@ -2060,3 +2060,22 @@ def symlink_or_copy(exp_dir: Path, src: str, dst: str):
     except OSError:
         copyfile(src=exp_dir / src, dst=exp_dir / dst)
     os.close(dir_fd)
+
+def num_tokens(
+    token_table: k2.SymbolTable, disambig_pattern: str = re.compile(r"^#\d+$")
+) -> int:
+    """Return the number of tokens excluding those from
+    disambiguation symbols.
+
+    Caution:
+      0 is not a token ID so it is excluded from the return value.
+    """
+    symbols = token_table.symbols
+    ans = []
+    for s in symbols:
+        if not disambig_pattern.match(s):
+            ans.append(token_table[s])
+    num_tokens = len(ans)
+    if 0 in ans:
+        num_tokens -= 1
+    return num_tokens
\ No newline at end of file