Class BooleanVar

Lib/tkinter/__init__.py:639–666

Value holder for boolean variables.

class BooleanVar(Variable):
    """Value holder for boolean variables."""
    _default = False

    def __init__(self, master=None, value=None, name=None):
        """Construct a boolean variable.

        MASTER can be given as master widget.
        VALUE is an optional value (defaults to False)
        NAME is an optional Tcl name (defaults to PY_VARnum).

        If NAME matches an existing variable and VALUE is omitted
        then the existing value is retained.
        """
        Variable.__init__(self, master, value, name)

    def set(self, value):
        """Set the variable to VALUE."""
        return self._tk.globalsetvar(self._name, self._tk.getboolean(value))

    initialize = set

    def get(self):
        """Return the value of the variable as a bool."""
        try:
            return self._tk.getboolean(self._tk.globalgetvar(self._name))
        except TclError:
            raise ValueError("invalid literal for getboolean()")


def mainloop(n=0):