python django中的名称未定义错误

import csv
import io
import re

from django.http import HttpResponse
from django.shortcuts import render
from django.views import generic

from ...forms import CsvUploadForm

import pandas as pd


class CsvImportView(generic.base.View):
    def getemailcolumn(self, sample):
        for key, val in sample:
           print(key, val)
           if re.match("^.+@([?)[a-zA-Z0-9-.]+.([a-zA-Z]{2,3}|[0-9]{1,3})(]?)$", val[0]) is not None:
              return key
        return None


    def post(self, request):
        form = CsvUploadForm(request.POST, request.FILES)

        if form.is_valid():
           fieldnames = ['first_name', 'email', 'last_name']

           csv = pd.read_csv(request.FILES['csv'])

           sample =csv.head();

           emailColumn = getemailcolumn(sample)

           return HttpResponse(sample)
        else:
          ...
          ...

当post方法被执行时,我得到一个name not defined错误

未定义名称“getemailcolumn”

我错过了什么?