Django的背景：分配

Question

，大家下午好之前引用局部變量，

我在我Django project開始有點問題，我的環境變量。我有一個讓我能夠完成某些過程的功能。特別是對我數據庫的一些研究並顯示結果。

但是我有一個變量的一個問題：folderId

我得到這個錯誤，我沒有找到一個方法來克服它：

Environment: 


Request Method: GET 
Request URL: http://localhost:8000/Identity/recherche 

Django Version: 1.10.3 
Python Version: 2.7.12 
Installed Applications: 
['django.contrib.admin', 
'django.contrib.auth', 
'django.contrib.contenttypes', 
'django.contrib.sessions', 
'django.contrib.messages', 
'django.contrib.staticfiles', 
'BirthCertificate', 
'Identity', 
'bootstrapform', 
'Accueil', 
'captcha', 
'django_countries', 
'log', 
'Mairie', 
'Table', 
'Recensement'] 
Installed Middleware: 
['django.contrib.sessions.middleware.SessionMiddleware', 
'django.middleware.locale.LocaleMiddleware', 
'django.middleware.common.CommonMiddleware', 
'django.middleware.csrf.CsrfViewMiddleware', 
'django.middleware.gzip.GZipMiddleware', 
'django.contrib.auth.middleware.AuthenticationMiddleware', 
'django.contrib.auth.middleware.SessionAuthenticationMiddleware', 
'django.contrib.messages.middleware.MessageMiddleware', 
'django.middleware.clickjacking.XFrameOptionsMiddleware', 
'django.middleware.security.SecurityMiddleware'] 



Traceback: 

File "/usr/local/lib/python2.7/site-packages/django/core/handlers/exception.py" in inner 
    39.    response = get_response(request) 

File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py" in _legacy_get_response 
    249.    response = self._get_response(request) 

File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py" in _get_response 
    187.     response = self.process_exception_by_middleware(e, request) 

File "/usr/local/lib/python2.7/site-packages/django/core/handlers/base.py" in _get_response 
    185.     response = wrapped_callback(request, *callback_args, **callback_kwargs) 

File "/usr/local/lib/python2.7/site-packages/django/contrib/auth/decorators.py" in _wrapped_view 
    23.     return view_func(request, *args, **kwargs) 

File "/Users/valentinjungbluth/Desktop/Django/Etat_civil/Identity/views.py" in Identity_Researching 
    121.   "folderId" : folderId, 

Exception Type: UnboundLocalError at /Identity/recherche 
Exception Value: local variable 'folderId' referenced before assignment 

我的功能看起來像：

@login_required 
def Identity_Researching(request) : 

    ####################### 
    # Display some arrays # 
    ####################### 

    identitys = Identity.objects.order_by("-id") 
    identity = identitys[:3] #The 3 last created forms 
    identity_France = identitys.filter(country=64)[:3] #The 3 last created form with BirthCity = France 

    ############################ 
    # People searching process # 
    ############################ 

    query_lastname = request.GET.get('q1') 
    query_firstname = request.GET.get('q1bis') 
    query_birthday = request.GET.get('q1ter') 

    if query_lastname or query_firstname or query_birthday : 

     query_lastname_list = Identity.objects.filter(lastname__contains=query_lastname, firstname__contains=query_firstname, birthday__contains=query_birthday) 

     title = str(query_lastname + "_" + query_firstname + "_" + query_birthday) 

     ########################################## 
     # Look if people directory already exist # 
     ########################################## 

     url = 'http://demodoc/services/rest/folder/listChildren?folderId=8552450' 
     payload = {'folderId': 8552450} 

     headers = {'Accept': 'application/json'} 
     r = requests.get(url, params=payload, headers=headers, auth=('etatcivil', '100%EC67')) 

     rbody = r.content 
     data = json.loads(rbody) 

     longueur = len(data) 

     i=0 
     list = [] 

     while i < longueur : 

      if data[i]["name"] == title : 

       list = [data[i]] 

      i = i+1 

     ############################################ 
     # We have correspondance, use ID directory # 
     ############################################ 

     if len(list) == 1 : 

      folderId = list[0]["id"] 

     else : 

      return HttpResponseRedirect('searched') 

    else : 
     query_lastname_list = Identity.objects.none() # == [] 


    if "Retour" in request.POST : 
     return HttpResponseRedirect('accueil') 

    context = { 
     "identity" : identity, 
     "identity_France" : identity_France, 
     "query_lastname" : query_lastname, 
     "query_firstname" : query_firstname, 
     "query_birthday" : query_birthday, 
     "query_lastname_list" : query_lastname_list, 
     "folderId" : folderId, 
     } 

    return render(request, 'resume.html', context) 

我錯過了什麼或訂單不正確？當我有這樣那樣的錯誤，我也不是很明白我有什麼爲了克服它做..

謝謝你的任何幫助:)

Answer 1

您正在使用內部的實例變量如果聲明。只要外面先創建它：

def Identity_Researching(request): 
    folderId = None 
    ... 

Answer 2

擴大對@贊布羅塔的回答，看看這個簡單的例子：

list = [1,2] 
if len(list) == 1: 
    folderId = list[0] 

print(folderId) 

在這種情況下，類似於你的程序的工作方式，folderId永遠不會定義，所以當試圖打印未定義的變量時將引發NameError。但是，使用此：

folderId = None 
list = [1,2] 
if len(list) == 1: 
    folderId = list[0] 

print(folderId) 

反而會打印None作爲folderId 已被定義，即使它的價值None。