How to check perform field validation in resource.py?

I am uploading a .xls file and need to check the below condition before it saves to the model/database. requirement: 1.how to count the total no of rows and compare it with some value and if len(row)<=count(any variable) . 2. how to reset count variable in 1 day.

resource.py

```
class CTSResource(resources.ModelResource):
   class meta:
      Model=CTA
   def before_import(self, dataset, using_transactions, dry_run, **kwargs):
      --Logic code---
      --Logic code---
```

I am trying to implement it at the file processing level in my views.py file as shown below.

    def CTA_upload(request):
        try:
            if request.method == 'POST':
                movie_resource = CTAResource()
                ##we will get data in movie_resources####
                dataset = Dataset()
                new_movie = request.FILES['file']
                if not new_movie.name.endswith('xls'):
                    messages.info(request, 'Sorry Wrong File Format.Please Upload valid format')
                    return render(request, 'app/uploadinfo.html')
                messages.info(request, 'Uploading Data Line by Line...')
                imported_data = dataset.load(new_movie.read(), format='xls')
                count = 1
                for data in imported_data:
                    value = CTA(
                        data[0],
                        data[1],
                        data[2],
                        data[3],
                        data[4],
                        data[5],
                        data[6],
                        data[7],
                        data[8],
                    )
                    count = count + 1
                    value.save()
                    # messages.info(request, count)
                # time.sleep(1)
                messages.info(request, 'File Uploaded Successfully...')
                
        except:
            messages.info(request,'Same Email ID has been observed more than once.Except that other records has been added../nPlease Make sure Email field should be unique.')
        
        return render(request,'app/cta.html')
    ```

I think dataset is object of tablib and you can count rows and column by using width and height attribute . But i didn’t check this manually . You can refer this link