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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_environment_paths(config, env):

 """
 Get environment paths from given environment variable.
 """

    if env is None:
        return config.get(Config.DEFAULTS, 'environment')

    # Config option takes precedence over environment key.
    if config.has_option(Config.ENVIRONMENTS, env):
        env = config.get(Config.ENVIRONMENTS, env).replace(' ', '').split(';')
    else:
        env = os.getenv(env)
        if env:
            env = env.split(os.pathsep)
    return [i for i in env if i]