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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 find_version(filename):
 """ Find package version in file. """

    import re
    content = read(filename)
    version_match = re.search(
        r"^__version__ = ['\"]([^'\"]*)['\"]", content, re.M
    )
    if version_match:
        return version_match.group(1)
    raise RuntimeError('Unable to find version string.')