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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 get_project_files():
 """Retrieve a list of project files, ignoring hidden files. :return: sorted list of project files :rtype: :class:`list` """

    if is_git_project():
        return get_git_project_files()

    project_files = []
    for top, subdirs, files in os.walk('.'):
        for subdir in subdirs:
            if subdir.startswith('.'):
                subdirs.remove(subdir)

        for f in files:
            if f.startswith('.'):
                continue
            project_files.append(os.path.join(top, f))

    return project_files