Limit the uploaded file size Django

limit_file_size.py

#In form.py
#The original source for this : http://djangosnippets.org/snippets/1303/

from django import forms
from django.template.defaultfilters import filesizeformat
from django.utils.translation import ugettext_lazy as _

# 2.5MB - 2621440
# 5MB - 5242880
# 10MB - 10485760
# 20MB - 20971520
# 50MB - 5242880
# 100MB 104857600
# 250MB - 214958080
# 500MB - 429916160
MAX_UPLOAD_SIZE = "5242880"

class UploadFileForm(forms.ModelForm):
    def clean(self):
        self.check_file()
        return self.cleaned_data

    def check_file(self):
        content = self.cleaned_data["event_file"]
        content_type = content.content_type.split('/')[0]
        if content._size > int(MAX_UPLOAD_SIZE):
            raise forms.ValidationError(_("Please keep file size under %s. Current file size %s")%(filesizeformat(MAX_UPLOAD_SIZE), filesizeformat(content._size)))
        return content
        
    class Meta:
        model = EventFile

This bring out this error
'InMemoryUploadedFile' object has no attribute '_size'

This bring out this error
'InMemoryUploadedFile' object has no attribute '_size'

try content.size