code: def is_visa_electron(n):
      
      n, length = str(n), len(str(n))
      form = ['026', '508', '844', '913', '917']
  
      if length == 16:
          if n[0] == '4':
              if ''.join(n[1:4]) in form or ''.join(n[1:6]) == '17500':
                  return True
      return False
docs: Checks if credit card number fits the visa electron format.