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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_url_from (base_url, recursion_level, aggregate, parent_url=None, base_ref=None, line=0, column=0, page=0, name=u"", parent_content_type=None, extern=None):
 """ Get url data from given base data. @param base_url: base url from a link tag @type base_url: string or None @param recursion_level: current recursion level @type recursion_level: number @param aggregate: aggregate object @type aggregate: aggregate.Consumer @param parent_url: parent url @type parent_url: string or None @param base_ref: base url from <base> tag @type base_ref string or None @param line: line number @type line: number @param column: column number @type column: number @param page: page number @type page: number @param name: link name @type name: string @param extern: (is_extern, is_strict) or None @type extern: tuple(int, int) or None """

    if base_url is not None:
        base_url = strformat.unicode_safe(base_url)
        # left strip for detection of URL scheme
        base_url_stripped = base_url.lstrip()
    else:
        base_url_stripped = base_url
    if parent_url is not None:
        parent_url = strformat.unicode_safe(parent_url)
    if base_ref is not None:
        base_ref = strformat.unicode_safe(base_ref)
    name = strformat.unicode_safe(name)
    url = absolute_url(base_url_stripped, base_ref, parent_url).lower()
    if ":" in url:
        scheme = url.split(":", 1)[0].lower()
    else:
        scheme = None
        if not (url or name):
            # use filename as base url, with slash as path seperator
            name = base_url.replace("\\", "/")
    allowed_schemes = aggregate.config["allowedschemes"]
    # ignore local PHP files with execution directives
    local_php = (parent_content_type == 'application/x-httpd-php' and
       '<?' in base_url and '?>' in base_url and scheme == 'file')
    if local_php or (allowed_schemes and scheme not in allowed_schemes):
        klass = ignoreurl.IgnoreUrl
    else:
        assume_local_file = (recursion_level == 0)
        klass = get_urlclass_from(scheme, assume_local_file=assume_local_file)
    log.debug(LOG_CHECK, "%s handles url %s", klass.__name__, base_url)
    return klass(base_url, recursion_level, aggregate,
                 parent_url=parent_url, base_ref=base_ref,
                 line=line, column=column, page=page, name=name, extern=extern)