Rethink add_eos by making it a flag so we don't force it on every

handler.

Signed-off-by: Dushyant Behl <dushyantbehl@in.ibm.com>

docs/advanced-data-preprocessing.md

@@ -204,14 +204,17 @@ Users can also pass any number of `kwargs` arguments required for each data hand
 
 #### Preexisting data handlers
 This library currently supports the following [preexisting data handlers](https://github.com/foundation-model-stack/fms-hf-tuning/blob/main/tuning/data/data_handlers.py#L156):
- - `tokenize_and_apply_input_masking`:
-    Tokenizes input text and applies masking to the labels for causal language modeling tasks, good for input/output datasets.
  - `add_tokenizer_eos_token`:
     Appends the tokenizer's EOS token to a specified dataset field.
  - `apply_custom_data_formatting_template`:
     Applies a custom template (e.g., Alpaca style) to format dataset elements.
+    By default this handler adds `EOS_TOKEN` which can be disabled by a handler argument, [see](https://github.com/foundation-model-stack/fms-hf-tuning/blob/main/tuning/data/data_handlers.py)
+ - `tokenize_and_apply_input_masking`:
+    Tokenizes input text and applies masking to the labels for causal language modeling tasks, good for input/output datasets.
+    By default this handler adds `EOS_TOKEN` which can be disabled by a handler argument, [see](https://github.com/foundation-model-stack/fms-hf-tuning/blob/main/tuning/data/data_handlers.py) 
  - `apply_custom_jinja_template`:
     Applies a custom jinja template (e.g., Alpaca style) to format dataset elements.
+    By default this handler adds `EOS_TOKEN` which can be disabled by a handler argument, [see](https://github.com/foundation-model-stack/fms-hf-tuning/blob/main/tuning/data/data_handlers.py)
  - `apply_tokenizer_chat_template`:
     Uses a tokenizer's chat template to preprocess dataset elements, good for single/multi turn chat templates.
  - `duplicate_columns`:

tuning/data/data_handlers.py

@@ -58,6 +58,7 @@ def tokenize_and_apply_input_masking(
     column_names: List[str],
     input_field_name: str,
     output_field_name: str,
+    add_eos_token: bool = True,
     **kwargs,
 ):
     """Function (data handler) to tokenize and apply instruction masking on dataset
@@ -68,6 +69,7 @@ def tokenize_and_apply_input_masking(
         column_names: Name of all the columns in the dataset.
         input_field_name: Name of the input (instruction) field in dataset
         output_field_name: Name of the output field in dataset
+        add_eos_token: should add tokenizer.eos_token to text or not, defaults to True
         **kwargs: Any additional args passed to the handler
     Returns:
         Formatted Dataset element with input_ids, labels and attention_mask columns
@@ -83,7 +85,11 @@ def tokenize_and_apply_input_masking(
     input_text = element[input_field_name]
     output_text = element[output_field_name]
 
-    combined = combine_sequence(input_text, output_text, eos_token=tokenizer.eos_token)
+    eos_token = ""
+    if add_eos_token:
+        eos_token = tokenizer.eos_token
+
+    combined = combine_sequence(input_text, output_text, eos_token=eos_token)
 
     tokenizer_kwargs = kwargs.get("tokenizer_kwargs", {})
 
@@ -131,6 +137,7 @@ def apply_custom_data_formatting_template(
     tokenizer: AutoTokenizer,
     dataset_text_field: str,
     template: str,
+    add_eos_token: bool = True,
     **kwargs,
 ):
     """Function (data handler) to format datasets with Alpaca style / other templates.
@@ -142,12 +149,14 @@ def apply_custom_data_formatting_template(
         dataset_text_field: Text column name of the dataset where formatted text is saved.
         template: Template to format data with. Features of Dataset
             should be referred to by {{key}}
+        add_eos_token: should add tokenizer.eos_token to text or not, defaults to True
     Returns:
         Formatted Dataset element by formatting dataset with template+tokenizer.EOS_TOKEN
         Saves the result to dataset_text_field argument.
     """
 
-    template += tokenizer.eos_token
+    if add_eos_token:
+        template += tokenizer.eos_token
 
     def replace_text(match_obj):
         captured_groups = match_obj.groups()
@@ -174,6 +183,7 @@ def apply_custom_jinja_template(
     tokenizer: AutoTokenizer,
     dataset_text_field: str,
     template: str,
+    add_eos_token: bool = True,
     **kwargs,
 ):
     """Function (data handler) to format datasets with jinja templates.
@@ -185,12 +195,14 @@ def apply_custom_jinja_template(
         dataset_text_field: formatted_dataset_field.
         template: Template to format data with. Features of Dataset
             should be referred to by {{key}}.
+        add_eos_token: should add tokenizer.eos_token to text or not, defaults to True
     Returns:
         Formatted HF Dataset element by formatting dataset with provided jinja template
         Saves the result to dataset_text_field argument.
     """
+    if add_eos_token:
+        template += tokenizer.eos_token
 
-    template += tokenizer.eos_token
     template = process_jinja_placeholders(template)
     env = SandboxedEnvironment(undefined=StrictUndefined)