ubelt.util_const moduleΒΆ

This module defines ub.NoParam. This is a robust sentinel value that can act like None when None might be a valid value. The value of NoParam is robust to reloading, pickling, and copying (i.e. var is ub.NoParam will return True after these operations).

Use cases that demonstrate the value of NoParam can be found in ubelt.util_dict, where it simplifies the implementation of methods that behave like dict.get().


>>> import ubelt as ub
>>> def func(a=ub.NoParam):
>>>     if a is ub.NoParam:
>>>         print('no param specified')
>>>     else:
>>>         print('a = {}'.format(a))
>>> func()
no param specified
>>> func(a=None)
a = None
>>> func(a=1)
a = 1
>>> # note: typically it is bad practice to use NoParam as an actual
>>> # (non-default) parameter. It goes against the sprit of the idea.
>>> func(a=ub.NoParam)
no param specified