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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 _replace_single(self, to_replace, value, inplace=False, filter=None, regex=False, convert=True, mask=None):
 """ Replace elements by the given value. Parameters to_replace : object or pattern Scalar to replace or regular expression to match. value : object Replacement object. inplace : bool, default False Perform inplace modification. filter : list, optional regex : bool, default False If true, perform regular expression substitution. convert : bool, default True If true, try to coerce any object types to better types. mask : array-like of bool, optional True indicate corresponding element is ignored. Returns ------- a new block, the result after replacing """

        inplace = validate_bool_kwarg(inplace, 'inplace')

        # to_replace is regex compilable
        to_rep_re = regex and is_re_compilable(to_replace)

        # regex is regex compilable
        regex_re = is_re_compilable(regex)

        # only one will survive
        if to_rep_re and regex_re:
            raise AssertionError('only one of to_replace and regex can be '
                                 'regex compilable')

        # if regex was passed as something that can be a regex (rather than a
        # boolean)
        if regex_re:
            to_replace = regex

        regex = regex_re or to_rep_re

        # try to get the pattern attribute (compiled re) or it's a string
        try:
            pattern = to_replace.pattern
        except AttributeError:
            pattern = to_replace

        # if the pattern is not empty and to_replace is either a string or a
        # regex
        if regex and pattern:
            rx = re.compile(to_replace)
        else:
            # if the thing to replace is not a string or compiled regex call
            # the superclass method -> to_replace is some kind of object
            return super().replace(to_replace, value, inplace=inplace,
                                   filter=filter, regex=regex)

        new_values = self.values if inplace else self.values.copy()

        # deal with replacing values with objects (strings) that match but
        # whose replacement is not a string (numeric, nan, object)
        if isna(value) or not isinstance(value, str):

            def re_replacer(s):
                try:
                    return value if rx.search(s) is not None else s
                except TypeError:
                    return s
        else:
            # value is guaranteed to be a string here, s can be either a string
            # or null if it's null it gets returned
            def re_replacer(s):
                try:
                    return rx.sub(value, s)
                except TypeError:
                    return s

        f = np.vectorize(re_replacer, otypes=[self.dtype])

        if filter is None:
            filt = slice(None)
        else:
            filt = self.mgr_locs.isin(filter).nonzero()[0]

        if mask is None:
            new_values[filt] = f(new_values[filt])
        else:
            new_values[filt][mask] = f(new_values[filt][mask])

        # convert
        block = self.make_block(new_values)
        if convert:
            block = block.convert(by_item=True, numeric=False)
        return block