Check and update model list in index.rst automatically (#7527)

* Check and update model list in index.rst automatically

* Check and update model list in index.rst automatically

* Adapt template

utils/check_copies.py

@@ -23,6 +23,7 @@ import tempfile
 # All paths are set with the intent you should run this script from the root of the repo with the command
 # python utils/check_copies.py
 TRANSFORMERS_PATH = "src/transformers"
+PATH_TO_DOCS = "docs/source"
 
 
 def find_code_in_transformers(object_name):
@@ -166,6 +167,113 @@ def check_copies(overwrite: bool = False):
             + diff
             + "\nRun `make fix-copies` or `python utils/check_copies --fix_and_overwrite` to fix them."
         )
+    check_model_list_copy(overwrite=overwrite)
+
+
+def get_model_list():
+    """ Extracts the model list from the README. """
+    # If the introduction or the conclusion of the list change, the prompts may need to be updated.
+    _start_prompt = "🤗 Transformers currently provides the following architectures"
+    _end_prompt = "1. Want to contribute a new model?"
+    with open(os.path.join("README.md"), "r", encoding="utf-8") as f:
+        lines = f.readlines()
+    # Find the start of the list.
+    start_index = 0
+    while not lines[start_index].startswith(_start_prompt):
+        start_index += 1
+    start_index += 1
+
+    result = []
+    current_line = ""
+    end_index = start_index
+
+    while not lines[end_index].startswith(_end_prompt):
+        if lines[end_index].startswith("1."):
+            if len(current_line) > 1:
+                result.append(current_line)
+            current_line = lines[end_index]
+        elif len(lines[end_index]) > 1:
+            current_line = f"{current_line[:-1]} {lines[end_index].lstrip()}"
+        end_index += 1
+    if len(current_line) > 1:
+        result.append(current_line)
+
+    return "".join(result)
+
+
+def split_long_line_with_indent(line, max_per_line, indent):
+    """ Split the `line` so that it doesn't go over `max_per_line` and adds `indent` to new lines. """
+    words = line.split(" ")
+    lines = []
+    current_line = words[0]
+    for word in words[1:]:
+        if len(f"{current_line} {word}") > max_per_line:
+            lines.append(current_line)
+            current_line = " " * indent + word
+        else:
+            current_line = f"{current_line} {word}"
+    lines.append(current_line)
+    return "\n".join(lines)
+
+
+def convert_to_rst(model_list, max_per_line=None):
+    """ Convert `model_list` to rst format. """
+    # Convert **[description](link)** to `description <link>`__
+    model_list = re.sub(r"\*\*\[([^\]]*)\]\(([^\)]*)\)\*\*", r"`\1 <\2>`__", model_list)
+
+    # Convert [description](link) to `description <link>`__
+    model_list = re.sub(r"\[([^\]]*)\]\(([^\)]*)\)", r"`\1 <\2>`__", model_list)
+
+    # Enumerate the lines properly
+    lines = model_list.split("\n")
+    result = []
+    for i, line in enumerate(lines):
+        line = re.sub(r"^\s*(\d+)\.", f"{i+1}.", line)
+        # Split the lines that are too long
+        if max_per_line is not None and len(line) > max_per_line:
+            prompt = re.search(r"^(\s*\d+\.\s+)\S", line)
+            indent = len(prompt.groups()[0]) if prompt is not None else 0
+            line = split_long_line_with_indent(line, max_per_line, indent)
+
+        result.append(line)
+    return "\n".join(result)
+
+
+def check_model_list_copy(overwrite=False, max_per_line=119):
+    """ Check the model lists in the README and index.rst are consistent and maybe `overwrite`. """
+    _start_prompt = "    This list is updated automatically from the README"
+    _end_prompt = ".. toctree::"
+    with open(os.path.join(PATH_TO_DOCS, "index.rst"), "r", encoding="utf-8") as f:
+        lines = f.readlines()
+    # Find the start of the list.
+    start_index = 0
+    while not lines[start_index].startswith(_start_prompt):
+        start_index += 1
+    start_index += 1
+
+    end_index = start_index
+    while not lines[end_index].startswith(_end_prompt):
+        end_index += 1
+    end_index -= 1
+
+    while len(lines[start_index]) <= 1:
+        start_index += 1
+    while len(lines[end_index]) <= 1:
+        end_index -= 1
+    end_index += 1
+
+    rst_list = "".join(lines[start_index:end_index])
+    md_list = get_model_list()
+    converted_list = convert_to_rst(md_list, max_per_line=max_per_line)
+
+    if converted_list != rst_list:
+        if overwrite:
+            with open(os.path.join(PATH_TO_DOCS, "index.rst"), "w", encoding="utf-8") as f:
+                f.writelines(lines[:start_index] + [converted_list] + lines[end_index:])
+        else:
+            raise ValueError(
+                "The model list in the README changed and the list in `index.rst` has not been updated. Run `make fix-copies` to fix this."
+            )
 
 
 if __name__ == "__main__":