DJANGO: object of type map is not JSON serializable

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def subs(request, pk):<br />
	sw = Swimmers.objects.filter(id=pk).values('sessions')<br />
	sw_list = map(int,sw)<br />
	sw_list = map(lambda x: x + 1, sw_list)<br />
	return JsonResponse(sw_list, safe=False)</pre><br />

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<pre>class Swimmers(models.Model):<br />
	name = models.CharField(max_length=200, blank=False)<br />
	lastname = models.CharField(max_length=200, blank=False)<br />
	idno = models.CharField(max_length=200, blank=False, null=True)<br />
	sessions = models.IntegerField(blank=False)<br />
	totalsessions = models.CharField(max_length=200, blank=False )<br />
	dateofpayment = models.CharField(max_length=200, blank=False)<br />
	session = models.ForeignKey(Session, on_delete=models.SET_NULL, null=True)<br />
<br />
	def __str__(self):<br />
		return self.name</pre><br />