If your bathroom door has a button lock from the inside and a little hole on the knob on the outside as seen in the above video then a screwdriver can certainly help you out.
How to get into a locked door from the outside.
Angle the card downward and situate it behind the bolt of the lock.
To open it up all you need to do is thread a coat hanger or hooked piece of wire through the top of the door and open the emergency latch which can also be done by the rope many emergency latches.
If the locking mechanism is a latchbolt the kind of bolt that is spring loaded and has one angled edge and the angled edge is facing away from you you can hook it with a wire hanger.
Then turn the door knob and shake the pin which should cause the lock to open.
You want to make sure that the card is perpendicular to the door.
Slide the long end of a credit card in between the door frame and the locking side of the door just above where the lock enters the frame.
To open a locked bathroom door from the outside place the point of a butter knife into the keyhole if it s a push button lock and turn the knife sideways.