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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 generate_settings():
 """ This command is run when ``default_path`` doesn't exist, or ``init`` is run and returns a string representing the default data to put into their settings file. """

    conf_file = os.path.join(os.path.dirname(base_settings.__file__),
                             'example', 'conf.py')
    conf_template = open(conf_file).read()
    default_url = 'http://salmon.example.com'
    site_url = raw_input("What will be the URL for Salmon? [{0}]".format(
        default_url))
    site_url = site_url or default_url
    secret_key = base64.b64encode(os.urandom(KEY_LENGTH))
    api_key = base64.b64encode(os.urandom(KEY_LENGTH))
    output = conf_template.format(api_key=api_key, secret_key=secret_key,
                                  site_url=site_url)
    return output