try this instead
Code:
from functools import partial
self.unshelve_TSBL1_button = QPushButton(
'Unshelve from TSBL 1', self)
self.unshelve_TSBL1_button.clicked.connect(partial(self.doUnshelve,'status:TSBL1shelved'))
self.l.addWidget(self.unshelve_TSBL1_button)