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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 url_to_fn(url):
 """ Convert `url` to filename used to download the datasets. ``http://kitakitsune.org/xe`` -> ``kitakitsune.org_xe``. Args: url (str):
 URL of the resource. Returns: str: Normalized URL. """

    url = url.replace("http://", "").replace("https://", "")
    url = url.split("?")[0]

    return url.replace("%", "_").replace("/", "_")