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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_fix_host (urlparts):
 """Unquote and fix hostname. Returns is_idn."""

    if not urlparts[1]:
        urlparts[2] = urllib.unquote(urlparts[2])
        return False
    userpass, netloc = urllib.splituser(urlparts[1])
    if userpass:
        userpass = urllib.unquote(userpass)
    netloc, is_idn = idna_encode(urllib.unquote(netloc).lower())
    # a leading backslash in path causes urlsplit() to add the
    # path components up to the first slash to host
    # try to find this case...
    i = netloc.find("\\")
    if i != -1:
        # ...and fix it by prepending the misplaced components to the path
        comps = netloc[i:] # note: still has leading backslash
        if not urlparts[2] or urlparts[2] == '/':
            urlparts[2] = comps
        else:
            urlparts[2] = "%s%s" % (comps, urllib.unquote(urlparts[2]))
        netloc = netloc[:i]
    else:
        # a leading ? in path causes urlsplit() to add the query to the
        # host name
        i = netloc.find("?")
        if i != -1:
            netloc, urlparts[3] = netloc.split('?', 1)
        # path
        urlparts[2] = urllib.unquote(urlparts[2])
    if userpass:
        # append AT for easy concatenation
        userpass += "@"
    else:
        userpass = ""
    if urlparts[0] in default_ports:
        dport = default_ports[urlparts[0]]
        host, port = splitport(netloc, port=dport)
        if host.endswith("."):
            host = host[:-1]
        if port != dport:
            host = "%s:%d" % (host, port)
        netloc = host
    urlparts[1] = userpass+netloc
    return is_idn