def _pretty(self, printer, *args):
     controls = self._print_sequence_pretty(self.controls, ",", printer, *args)
     gate = printer._print(self.gate)
     gate_name = stringPict(unicode(self.gate_name))
     first = self._print_subscript_pretty(gate_name, controls)
     gate = self._print_parens_pretty(gate)
     final = prettyForm(*first.right((gate)))
     return final

            def render(self, *args, **kwargs):
                ar = e.args  # just to shorten things
                settings = printer._settings if printer else {}
                if printer:
                    use_unicode = printer._use_unicode
                else:
                    from sympy.printing.pretty.pretty_symbology import (
                        pretty_use_unicode)
                    use_unicode = pretty_use_unicode()
                mpp = printer if printer else VectorPrettyPrinter(settings)
                if len(ar) == 0:
                    return unicode(0)
                bar = u"\N{CIRCLED TIMES}" if use_unicode else "|"
                ol = []  # output list, to be concatenated to a string
                for i, v in enumerate(ar):
                    # if the coef of the dyadic is 1, we skip the 1
                    if ar[i][0] == 1:
                        ol.extend([u" + ",
                                  mpp.doprint(ar[i][1]),
                                  bar,
                                  mpp.doprint(ar[i][2])])

                    # if the coef of the dyadic is -1, we skip the 1
                    elif ar[i][0] == -1:
                        ol.extend([u" - ",
                                  mpp.doprint(ar[i][1]),
                                  bar,
                                  mpp.doprint(ar[i][2])])

                    # If the coefficient of the dyadic is not 1 or -1,
                    # we might wrap it in parentheses, for readability.
                    elif ar[i][0] != 0:
                        if isinstance(ar[i][0], Add):
                            arg_str = mpp._print(
                                ar[i][0]).parens()[0]
                        else:
                            arg_str = mpp.doprint(ar[i][0])
                        if arg_str.startswith(u"-"):
                            arg_str = arg_str[1:]
                            str_start = u" - "
                        else:
                            str_start = u" + "
                        ol.extend([str_start, arg_str, u" ",
                                  mpp.doprint(ar[i][1]),
                                  bar,
                                  mpp.doprint(ar[i][2])])

                outstr = u"".join(ol)
                if outstr.startswith(u" + "):
                    outstr = outstr[3:]
                elif outstr.startswith(" "):
                    outstr = outstr[1:]
                return outstr

            def render(self, *args, **kwargs):
                ar = e.args  # just to shorten things
                if len(ar) == 0:
                    return unicode(0)
                settings = printer._settings if printer else {}
                vp = printer if printer else VectorPrettyPrinter(settings)
                pforms = []  # output list, to be concatenated to a string
                for i, v in enumerate(ar):
                    for j in 0, 1, 2:
                        # if the coef of the basis vector is 1, we skip the 1
                        if ar[i][0][j] == 1:
                            pform = vp._print(ar[i][1].pretty_vecs[j])
                        # if the coef of the basis vector is -1, we skip the 1
                        elif ar[i][0][j] == -1:
                            pform = vp._print(ar[i][1].pretty_vecs[j])
                            pform= prettyForm(*pform.left(" - "))
                            bin = prettyForm.NEG
                            pform = prettyForm(binding=bin, *pform)
                        elif ar[i][0][j] != 0:
                            # If the basis vector coeff is not 1 or -1,
                            # we might wrap it in parentheses, for readability.
                            if isinstance(ar[i][0][j], Add):
                                pform = vp._print(
                                    ar[i][0][j]).parens()
                            else:
                                pform = vp._print(
                                    ar[i][0][j])
                            pform = prettyForm(*pform.right(" ",
                                                ar[i][1].pretty_vecs[j]))
                        else:
                            continue
                        pforms.append(pform)

                pform = prettyForm.__add__(*pforms)
                kwargs["wrap_line"] = kwargs.get("wrap_line")
                kwargs["num_columns"] = kwargs.get("num_columns")
                out_str = pform.render(*args, **kwargs)
                mlines = [line.rstrip() for line in out_str.split("\n")]
                return "\n".join(mlines)

            def render(self, *args, **kwargs):
                self = e
                ar = self.args  # just to shorten things
                if len(ar) == 0:
                    return unicode(0)
                settings = printer._settings if printer else {}
                vp = printer if printer else VectorPrettyPrinter(settings)
                ol = []  # output list, to be concatenated to a string
                for i, v in enumerate(ar):
                    for j in 0, 1, 2:
                        # if the coef of the basis vector is 1, we skip the 1
                        if ar[i][0][j] == 1:
                            ol.append(u(" + ") + ar[i][1].pretty_vecs[j])
                        # if the coef of the basis vector is -1, we skip the 1
                        elif ar[i][0][j] == -1:
                            ol.append(u(" - ") + ar[i][1].pretty_vecs[j])
                        elif ar[i][0][j] != 0:
                            # If the basis vector coeff is not 1 or -1,
                            # we might wrap it in parentheses, for readability.
                            if isinstance(ar[i][0][j], Add):
                                arg_str = vp._print(
                                    ar[i][0][j]).parens()[0]
                            else:
                                arg_str = (vp.doprint(
                                    ar[i][0][j]))

                            if arg_str[0] == u("-"):
                                arg_str = arg_str[1:]
                                str_start = u(" - ")
                            else:
                                str_start = u(" + ")
                            ol.append(str_start + arg_str + ' ' +
                                      ar[i][1].pretty_vecs[j])
                outstr = u("").join(ol)
                if outstr.startswith(u(" + ")):
                    outstr = outstr[3:]
                elif outstr.startswith(" "):
                    outstr = outstr[1:]
                return outstr

 def _pretty(self, printer, *args):
     targets = self._print_sequence_pretty(
         self.targets, ',', printer, *args)
     gate_name = stringPict(unicode(self.gate_name))
     return self._print_subscript_pretty(gate_name, targets)

def xstr(*args):
    """call str or unicode depending on current mode"""
    if _use_unicode:
        return unicode(*args)
    else:
        return str(*args)

#.........这里部分代码省略.........
                                 "compatible object if viewer=\"BytesIO\"")
        elif viewer not in special and not find_executable(viewer):
            raise SystemError("Unrecognized viewer: %s" % viewer)


    if preamble is None:
        actual_packages = packages + ("amsmath", "amsfonts")
        if euler:
            actual_packages += ("euler",)
        package_includes = "\n" + "\n".join(["\\usepackage{%s}" % p
                                             for p in actual_packages])

        preamble = r"""\documentclass[12pt]{article}
\pagestyle{empty}
%s

\begin{document}
""" % (package_includes)
    else:
        if len(packages) > 0:
            raise ValueError("The \"packages\" keyword must not be set if a "
                             "custom LaTeX preamble was specified")
    latex_main = preamble + '\n%s\n\n' + r"\end{document}"

    if isinstance(expr, str):
        latex_string = expr
    else:
        latex_string = latex(expr, mode='inline', **latex_settings)

    try:
        workdir = tempfile.mkdtemp()

        with io.open(join(workdir, 'texput.tex'), 'w', encoding='utf-8') as fh:
            fh.write(unicode(latex_main) % u_decode(latex_string))

        if outputTexFile is not None:
            shutil.copyfile(join(workdir, 'texput.tex'), outputTexFile)

        if not find_executable('latex'):
            raise RuntimeError("latex program is not installed")

        try:
            check_output(['latex', '-halt-on-error', '-interaction=nonstopmode',
                          'texput.tex'], cwd=workdir, stderr=STDOUT)
        except CalledProcessError as e:
            raise RuntimeError(
                "'latex' exited abnormally with the following output:\n%s" %
                e.output)

        if output != "dvi":
            defaultoptions = {
                "ps": [],
                "pdf": [],
                "png": ["-T", "tight", "-z", "9", "--truecolor"],
                "svg": ["--no-fonts"],
            }

            commandend = {
                "ps": ["-o", "texput.ps", "texput.dvi"],
                "pdf": ["texput.dvi", "texput.pdf"],
                "png": ["-o", "texput.png", "texput.dvi"],
                "svg": ["-o", "texput.svg", "texput.dvi"],
            }

            if output == "svg":
                cmd = ["dvisvgm"]