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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def search_file(search_root, search_filename, instance_relative_root=False):
 """ Search for a filename in a specific search root dir. :param search_root: root dir to search :param search_filename: filename to search (no extension) :param instance_relative_root: search root is relative to instance path :return: tuple(full_file_path, extension without heading dot) """

        if instance_relative_root:
            search_root = os.path.join(current_app.instance_path, search_root)
        file_path = None
        file_ext = None
        for file in os.listdir(search_root):
            filename, ext = os.path.splitext(file)
            if filename == search_filename and ext and ext != '.':
                file_path = os.path.join(search_root, filename + ext)
                file_ext = ext[1:]  # remove heading '.' (dot)
                break
        return file_path, file_ext