Range applied on field

Sir, how to apply range on a single field in a module.

What do you mean by applying a range on a field?
Do you mean a constraint? This can be done by defining a domain on the field.

I also can imagine a min / max value for a “Number” field like integer, float, numeric … e.g.

counter = fields.Integer('Counts', min=0, max=100)

An user can only select a value between 0 and 100.

In this case you can use:

counter = fields.Integer('Counts',
        ('counter', '>=', 0),
        ('counter', '<=', 100),