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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():
 """Only define version in one place"""

    version_file = read_file('__init__.py')
    version_match = re.search(r'^__version__ = ["\']([^"\']*)["\']',
                              version_file, re.M)
    if version_match:
        return version_match.group(1)
    raise RuntimeError('Unable to find version string.')