title: How to get field's default value from other field in odoo?
body: <p>I my module I have an entity "Bill" with two float fields "total" and "remaining" I want "remaining" to take its default value from "total". How can I do that?
  I have tried these with but when I try to create a new "Bill" it shows an error "TypeError: float() argument must be a string or a number, not 'Float'"</p>
  
  <p><code>
  total = fields.Float(string='Total', digits=(10, 2))
  remaining = fields.Float(string='Remaining', digits=(10, 2) default=total)
  </code></p>