def autoIndentBlock(self, block, char = '\n'):
        """Indent block after Enter pressed or trigger character typed
        """
        cursor = QTextCursor(block)
        currentText = block.text()
        spaceAtStartLen = len(currentText) - len(currentText.lstrip())
        currentIndent = currentText[:spaceAtStartLen]
        indent = self._smartIndenter.computeIndent(block, char)
        if indent is not None and indent != currentIndent:
            self._qpart.replaceText(block.position(), spaceAtStartLen, indent)
def voltage_fft(title, order, voltage, ax=0):
    """plot FFT harmonics of voltage"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('{} / V'.format(title))
    ax.grid(True)
    if max(order) < 5:
        order += [5]
        voltage += [0]
    try:
        bw = 2.5E-2*max(order)
        ax.bar(order, voltage, width=bw, align='center')
    except ValueError:  # empty sequence
        pass