email not display correctly when send email by code with template

I want to send RFQ to vendor of purchase order by code my code is as below

 @api.multi     
 def send_mail(self,purchase_id):       
 email_template_obj = self.env['mail.template']    
 template_ids = email_template_obj.search([('name','=','RFQ - Send by Email'),('model_id.model', '=', 'purchase.order')])        values={}    
 if template_ids:      
 email=self.env['mail.template'].browse(template_ids.id).send_mail(purchase_id)              self.env['mail.mail'].browse(email).send()     

 return True

This code send email to vendor as like below attachment.

https://gyazo.com/4c29e8ae42b9c92bb18a538a056c1782

I want emai like as below image,when i send rfq by button "send RFQ by mail" of purchase order.I need email body should be like below image when i am sending email from code

https://gyazo.com/8919f9a0807b2e74c024c004e3bc5e72

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