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().
The value of NoParam is robust to reloading, pickling, and copying. See
[SO_41048643] for more details.
References
Example
>>> 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