Django-检查数据库中是否存在变量集并对其进行处理？

Question

So I have a Django App, where a CSV-File can be uploaded. My CSV-File has 9 columns that can be divided into two "datasets" where the first 5 columns need to be handled as one information and the other 4 need to be handled as another information. I cannot put the first 5 in one cell and the other ones in another cell. I would like to check whether or not the first dataset exists and if it does, process it. The same applies to the other dataset. And if both datasets do not exist already it should just update the Database with get_or_create.

Here is my views.py idea

    def import_csv(request):
    if request.method == "POST":
        with open('C:/Users/admin/Desktop/djangoexcel/b.csv') as file:
            reader = csv.reader(file)
            for row in reader:
                var = CSV_File4.objects.filter(
                    attr1=row[0], attr2=row[1], attr3=row[2], attr4=row[3], attr5=row[4],
                )
                if var.exists():
                    TemplateResponse(request, "documents/replace_entry.html", {'var' : var})
                else:
                    for row in reader:
                        switch = CSV_File4.objects.filter(
                            attr6=row[5], attr7=row[6], attr8=row[7], attr9=row[8]
                        )
                        if var2.exists():
                            TemplateResponse(request, "documents/replace_entry.html", {'var2' : var2})
                        else:
                            for row in reader:
                                _, p = CSV_File4.objects.get_or_create(
                                    attr1=row[0], attr2=row[1], attr3=row[2], attr4=row[3], attr5=row[4],
                                    attr6=row[5], attr7=row[6], attr8=row[7], attr9=row[8]
                                )


            return redirect('documents:index')
    form = UploadFileForm()
    return render(
        request, "documents/csv_upload.html", {"form": form}
    )

It should look something like this. How can I make this work. It was just an idea with filter() and exists() but is there a Python way to do something like this? Any help would be appreciated.

Answer 1

Currently, you are trying to recursively iterate through reader three times. That's not possible, because it is an Iterator , not a list . Anyway, you only need to do it once and then work on that particular line, before skipping to the next.

def import_csv(request):
    if request.method == "POST":
        with open('C:/Users/admin/Desktop/djangoexcel/b.csv') as file:
            reader = csv.reader(file)
            for row in reader:
                ds1 = CSV_File4.objects.filter(
                    attr1=row[0], attr2=row[1], attr3=row[2], attr4=row[3], attr5=row[4],
                ).exists()
                ds2 = CSV_File4.objects.filter(
                    attr6=row[5], attr7=row[6], attr8=row[7], attr9=row[8]
                ).exists()

                if ds1:
                    pass  # Process first dataset
                if ds2:
                    pass  # Process second dataset
                if not (ds1 and ds2):
                    _, p = CSV_File4.objects.get_or_create(
                        attr1=row[0], attr2=row[1], attr3=row[2], attr4=row[3], attr5=row[4],
                        attr6=row[5], attr7=row[6], attr8=row[7], attr9=row[8]
                    )

            return redirect('documents:index')

    return render(
        request, "documents/csv_upload.html", {"form": UploadFileForm()}
    )