Using a class field in another fields
<p>I have a field in a class that depends on another field in the same class but I have a problem to code:</p>

<p><code>class myclass(models.Model):
    nation = [('sp', 'spain'), ('fr', 'france')]
    nationality = models.CharField(max_length=2, choices=nation)
    first_name = models.CharField(max_length=2, choices=name)</code></p>

<p>I want to put name = [('ro', 'rodrigo'), ('ra', 'raquel')] if nation = spain and  name = [('lu', 'luis'), ('ch', 'chantal')] if nation = france.</p>

<p>How I can do that? Thanks!</p>