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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 package_data(pkg, root_list):
 """Generic function to find package_data for `pkg` under `root`."""

    data = []
    for root in root_list:
        for dirname, _, files in os.walk(os.path.join(pkg, root)):
            for fname in files:
                data.append(os.path.relpath(os.path.join(dirname, fname), pkg))

    return {pkg: data}