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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 plot_fixed_x(self, x_values, x_derivative=0, steps=1000, smooth=0, simple='auto', ymin="auto", ymax="auto", format=True, clear=1):
 """ plots the data at fixed x-value, so z vs x """

        if simple=='auto': simple=self.simple
        
        # get the min and max
        if ymin=="auto": ymin = self.ymin
        if ymax=="auto": ymax = self.ymax
        if clear: _pylab.gca().clear()

        if not type(x_values) in [type([]), type(_pylab.array([]))]: x_values = [x_values]

        for x in x_values:
    
            # define a new simple function to plot, then plot it
            def f(y): return self.evaluate(x, y, x_derivative, smooth, simple)
            _pylab_help.plot_function(f, ymin, ymax, steps, 0, False)

            # label it
            a = _pylab.gca()
            a.set_xlabel(self.ylabel)
            if x_derivative: a.set_ylabel(str(x_derivative)+" "+str(self.xlabel)+" derivative of "+self.zlabel)
            else:            a.set_ylabel(self.zlabel)
            a.set_title(self._path+"\nSpline array plot at fixed x = "+self.xlabel)
            a.get_lines()[-1].set_label("x ("+self.xlabel+") = "+str(x))

        if format: _s.format_figure()
        return a