How to use nbconvertExecutePreprocessor

execute_nb.py

#From nbdev.export2html
class ExecuteShowDocPreprocessor(ExecutePreprocessor):
    "An `ExecutePreprocessor` that only executes `show_doc` and `import` cells"
    def preprocess_cell(self, cell, resources, index):
        if not check_re(cell, _re_notebook2script):
            if check_re(cell, _re_show_doc):
                return super().preprocess_cell(cell, resources, index)
            elif check_re_multi(cell, [_re_import, _re_lib_import.re]):
                if check_re_multi(cell, [_re_export, 'show_doc', '^\s*#\s*import']):
#                     r = list(filter(_non_comment_code, cell['source'].split('\n')))
#                     if r: print("You have import statements mixed with other code", r)
                    return super().preprocess_cell(cell, resources, index)
#                 try: return super().preprocess_cell(cell, resources, index)
#                 except: pass
        return cell, resources


#export
def _import_show_doc_cell(mods=None):
    "Add an import show_doc cell."
    source = f"from nbdev.showdoc import show_doc"
    if mods is not None:
        for mod in mods: source += f"\nfrom {get_config().lib_name}.{mod} import *"
    return {'cell_type': 'code',
            'execution_count': None,
            'metadata': {'hide_input': True},
            'outputs': [],
            'source': source}

def execute_nb(nb, mod=None, metadata=None, show_doc_only=True):
    "Execute `nb` (or only the `show_doc` cells) with `metadata`"
    mods = ([] if mod is None else [mod]) + _gather_export_mods(nb['cells'])
    nb['cells'].insert(0, _import_show_doc_cell(mods))
    ep_cls = ExecuteShowDocPreprocessor if show_doc_only else ExecutePreprocessor
    ep = ep_cls(timeout=600, kernel_name='python3')
    metadata = metadata or {}
    pnb = nbformat.from_dict(nb)
    ep.preprocess(pnb, metadata)
    return pnb