def onAutoIndentTriggered(self):
        """Indent current line or selected lines
        """
        cursor = self._qpart.textCursor()

        startBlock = self._qpart.document().findBlock(cursor.selectionStart())
        endBlock = self._qpart.document().findBlock(cursor.selectionEnd())

        if startBlock != endBlock:  # indent multiply lines
            stopBlock = endBlock.next()

            block = startBlock

            with self._qpart:
                while block != stopBlock:
                    self.autoIndentBlock(block, '')
                    block = block.next()
        else:  # indent 1 line
            self.autoIndentBlock(startBlock, '')
def test_lens_formula():
    u, v, f = symbols('u, v, f')
    assert lens_formula(focal_length=f, u=u) == f*u/(f + u)
    assert lens_formula(focal_length=f, v=v) == f*v/(f - v)
    assert lens_formula(u=u, v=v) == u*v/(u - v)
    assert lens_formula(u=oo, v=v) == v
    assert lens_formula(u=oo, v=oo) is oo
    assert lens_formula(focal_length=oo, u=u) == u
    assert lens_formula(u=u, v=oo) == -u
    assert lens_formula(focal_length=oo, v=oo) is -oo
    assert lens_formula(focal_length=oo, v=v) == v
    assert lens_formula(focal_length=f, v=oo) == -f
    assert lens_formula(focal_length=oo, u=oo) is oo
    assert lens_formula(focal_length=oo, u=u) == u
    assert lens_formula(focal_length=f, u=oo) == f
    raises(ValueError, lambda: lens_formula(focal_length=f, u=u, v=v))