title: How to remove third brackets '[]' from django built in unique field validation erro response
body: <p><strong>Here is my model</strong></p>
  <p>In this CustomerAdd table, I've designed customer_phone with Django builtins unique=True. And for these unique fields, Django raised
  validation error following:
  {
  &quot;customer_phone&quot;: [
  &quot;This customer_phone has already been registered.&quot;
  ]
  }
  How to remove third brackets from built-in validation error! Please help me.</p>
  <pre><code>class CustomerAdd(models.Model):
      user = models.ForeignKey('accounts.CustomUser', on_delete=models.CASCADE)
      is_customer = models.BooleanField('customer status', default=True)
      is_supplier = models.BooleanField('supplier status', default=False)
      customer_name = models.CharField(max_length=100)
      customer_phone = models.CharField(max_length=15, unique=True, error_messages={'unique': &quot;This customer_phone has &quot;
                                                                                              &quot;already been registered.&quot;})
      previous_due = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
      date = models.DateField(auto_now_add=True)
      picture = models.ImageField(upload_to='customer_add_pics', default='images.png')
  
      def __str__(self):
          return self.customer_name
  
      class Meta:
          verbose_name = &quot;Customer Add&quot;
          verbose_name_plural = &quot;Customer Add&quot;
  </code></pre>
  <p><strong>And here is API Response:</strong></p>
  <pre><code>{
      &quot;customer_phone&quot;: [
          &quot;This customer_phone has already been registered.&quot;
      ]
  }
  </code></pre>