How to use the phonenumbers.util.u function in phonenumbers

def _expand_formatting_rule(rule, national_prefix):
    """Formatting rules can include terms "$NP" and "$FG",
    These get replaced with:
     "$NP" => the national prefix
     "$FG" => the first group, i.e. "$1"
    """
    if rule is None:
        return None
    if national_prefix is None:
        national_prefix = u("")
    rule = re.sub(u(r"\$NP"), national_prefix, rule)
    rule = re.sub(u(r"\$FG"), u("$1"), rule)
    return rule

def __unicode__(self):
        return u(self.o)

def __unicode__(self):
        return u(self.o)

def __unicode__(self):
        return u(self.number_format)

# expand abbreviations
                self.o.domestic_carrier_code_formatting_rule = _expand_formatting_rule(self.o.domestic_carrier_code_formatting_rule,
                                                                                       national_prefix)
            else:
                # set to territory-wide formatting rule
                self.o.domestic_carrier_code_formatting_rule = carrier_code_formatting_rule
            if self.o.domestic_carrier_code_formatting_rule is not None:
                # Replace '$1' etc  with '\1' to match Python regexp group reference format
                self.o.domestic_carrier_code_formatting_rule = re.sub(r'\$(\d)', r'\\\1', self.o.domestic_carrier_code_formatting_rule)

            self.o.format = _get_unique_child_value(xtag, 'format')
            if self.o.format is None:
                raise Exception("No format pattern found")
            else:
                # Replace '$1' etc  with '\1' to match Python regexp group reference format
                self.o.format = re.sub(r'\$', u(r'\\'), self.o.format)
            xleading_digits = xtag.findall("leadingDigits")
            for xleading_digit in xleading_digits:
                self.o.leading_digits_pattern.append(_dews_re(xleading_digit.text))

            # Add this NumberFormat object into the owning metadata
            owning_xterr.o.number_format.append(self.o)

            # Extract the pattern for international format; if not present, use the national format.
            # If the intlFormat is set to "NA" the intlFormat should be ignored.
            self.io = NumberFormat(pattern=self.o.pattern,
                                   leading_digits_pattern=self.o.leading_digits_pattern)
            self.io._mutable = True

            intl_format = _get_unique_child_value(xtag, "intlFormat")
            if intl_format is None:
                # Default to use the same as the national pattern if none is defined.

def _expand_formatting_rule(rule, national_prefix):
    """Formatting rules can include terms "$NP" and "$FG",
    These get replaced with:
     "$NP" => the national prefix
     "$FG" => the first group, i.e. "$1"
    """
    if rule is None:
        return None
    if national_prefix is None:
        national_prefix = u("")
    rule = re.sub(u(r"\$NP"), national_prefix, rule)
    rule = re.sub(u(r"\$FG"), u("$1"), rule)
    return rule

def __unicode__(self):
        return u("\n").join([u("%s: %s") % (country_id, territory) for country_id, territory in self.territory.items()])

def _expand_formatting_rule(rule, national_prefix):
    """Formatting rules can include terms "$NP" and "$FG",
    These get replaced with:
     "$NP" => the national prefix
     "$FG" => the first group, i.e. "$1"
    """
    if rule is None:
        return None
    if national_prefix is None:
        national_prefix = u("")
    rule = re.sub(u(r"\$NP"), national_prefix, rule)
    rule = re.sub(u(r"\$FG"), u("$1"), rule)
    return rule