Updates the progress bar.
        # Arguments
            current: Index of current step.
            values: List of tuples (name, value_for_last_step).
                The progress bar will display averages for these values.
            exact: List of tuples (name, value_for_last_step).
                The progress bar will display these values directly.

def update(self, current, values=[], exact=[], strict=[]):
        """
        Updates the progress bar.
        # Arguments
            current: Index of current step.
            values: List of tuples (name, value_for_last_step).
                The progress bar will display averages for these values.
            exact: List of tuples (name, value_for_last_step).
                The progress bar will display these values directly.
        """

        for k, v in values:
            if k not in self.sum_values:
                self.sum_values[k] = [v * (current - self.seen_so_far), current - self.seen_so_far]
                self.unique_values.append(k)
            else:
                self.sum_values[k][0] += v * (current - self.seen_so_far)
                self.sum_values[k][1] += (current - self.seen_so_far)

        for cells in exact:
            k, v, w = cells[0], cells[1], 4
            if len(cells) == 3:
                w = cells[2]
            if k not in self.sum_values:
                self.unique_values.append(k)
            self.sum_values[k] = [v, 1, w]

        for k, v in strict:
            if k not in self.sum_values:
                self.unique_values.append(k)
            self.sum_values[k] = v

        self.seen_so_far = current

        now = time.time()
        if self.verbose == 1:
            prev_total_width = self.total_width
            sys.stdout.write("\b" * prev_total_width)
            sys.stdout.write("\r")

            numdigits = 0 if self.target == 0 or math.isnan(self.target) else int(np.floor(np.log10(self.target))) + 1
            barstr = '%%%dd/%%%dd [' % (numdigits, numdigits)
            bar = barstr % (current, self.target)
            prog = 0 if self.target == 0 else float(current) / self.target
            prog_width = int(self.width * prog)
            if prog_width > 0:
                bar += ('=' * (prog_width - 1))
                if current < self.target:
                    bar += '>'
                else:
                    bar += '='
            bar += ('.' * (self.width - prog_width))
            bar += ']'
            sys.stdout.write(bar)
            self.total_width = len(bar)

            if current:
                time_per_unit = (now - self.start) / current
            else:
                time_per_unit = 0
            eta = time_per_unit * (self.target - current)
            info = ''
            if current < self.target:
                info += ' - ETA: %ds' % eta
            else:
                info += ' - %ds' % (now - self.start)
            for k in self.unique_values:
                if type(self.sum_values[k]) is list:
                    info += (' - %s: %.' + str(self.sum_values[k][2]) + 'f') % (
                        k, self.sum_values[k][0] / max(1, self.sum_values[k][1]))
                else:
                    info += ' - %s: %s' % (k, self.sum_values[k])

            self.total_width += len(info)
            if prev_total_width > self.total_width:
                info += ((prev_total_width - self.total_width) * " ")

            sys.stdout.write(info)
            sys.stdout.flush()

            if current >= self.target:
                sys.stdout.write("\n")

        if self.verbose == 2:
            if current >= self.target:
                info = '%ds' % (now - self.start)
                for k in self.unique_values:
                    info += ' - %s: %.4f' % (k, self.sum_values[k][0] / max(1, self.sum_values[k][1]))
                sys.stdout.write(info + "\n")