我有一个django形式：
class ParameterForm(forms.Form):
pcat = forms.IntegerField()
gpa = forms.FloatField()
city = forms.CharField(required = False)
state = forms.CharField(required = False, min_length = 2, max_length = 2)
当我在python shell中测试这个表单时，我能够捕获丢失的数据，如下所示：
>> parameters = {'pcat' : 70, 'gpa' : 3.5, 'state' : 'TX'}
>> form = ParameterForm(parameters)
>> try:
.. form.data['city']
.. except KeyError:
.. print "No city"
>> No city
但是，当我尝试在我的视图中使用相同的逻辑时，异常永远不会引发，并且函数会继续执行，直到缺少的数据导致它中断。
来自views.py的：
def sByInfo(request):
print "\n \n NEW CALL"
parameter_form = ParameterForm(request.GET)
if parameter_form.is_valid():
ranked = Ranked.objects.all()
unranked = Unranked.objects.all()
ranked_matches = [] # List for ranked institution matches
unranked_matches = [] # List for unranked institution matches
try:
gpa = parameter_form.data['gpa']
gpa = float(gpa)
print gpa
pcat = parameter_form.data['pcat']
pcat = int(pcat)
print pcat
try:
city = parameter_form.data['city']
print city
state = parameter_form.data['state']
print state
position = getPos(city, state)
lati = Decimal(position['lat'])
loni = Decimal(position['lon'])
print "\n RANKED"
for x in ranked:
print x.name
average_gpa = (x.gpa_expected + x.gpa_overall) / 2
print average_gpa
if gpa >= average_gpa:
print "GPA good"
try:
ranked_matches.index(x)
print "School already added"
except ValueError:
ranked_matches.append(x)
print "School added"
else:
print "GPA too low"
if pcat >= x.min_pcat:
try:
ranked_matches.index(x)
print "School already added"
except ValueError:
ranked_matches.append(x)
print "School added"
else:
print "PCAT too low"
lat = Decimal(x.lat)
lon = Decimal(x.lon)
difference = posDifference(lati, loni, lat, lon)
print "Distance is {} miles".format(difference)
if difference <= 150:
try:
ranked_matches.index(x)
print "School already added"
except ValueError:
ranked_matches.append(x)
print "School added"
else:
print "School out of range"
print "\n UNRANKED"
for y in unranked:
print y.name
average_gpa = (y.gpa_expected + y.gpa_overall) / 2
if gpa >= average_gpa:
try:
unranked_matches.index(y)
print "School already added"
except ValueError:
unranked_matches.append(y)
print "School added"
else:
print "GPA too low"
if pcat >= y.min_pcat:
try:
unranked_matches.index(y)
print "School already added"
except ValueError:
unranked_matches.append(y)
print "School added"
else:
print "PCAT too low"
lat = Decimal(y.lat)
lon = Decimal(y.lon)
difference = posDifference(lati, loni, lat, lon)
print "Distance is {} miles".format(difference)
if difference <= 150:
try:
unranked_matches.index(y)
print "School already added"
except ValueError:
unranked_matches.append(y)
print "School added"
else:
print "School out of range"
except KeyError: ## City or State was not submitted
print "City or state missing"
try:
state = request.GET['state']
for x in ranked:
average_gpa = (x.gpa_overall + x.gpa_expected) / 2
if gpa >= average_gpa:
try:
ranked_matches.index(x)
print "School already added"
except ValueError:
ranked_matches.append(x)
print "School added"
else:
print "GPA too low"
if pcat >= x.min_pcat:
try:
ranked_matches.index(x)
print "School already added"
except ValueError:
ranked_matches.append(x)
print "School added"
else:
print "PCAT too low"
if state.lower() == x.state.lower():
try:
ranked_matches.index(x)
print "School already added"
except ValueError:
ranked_matches.append(x)
print "School added"
else:
print "School not in state"
for y in unranked:
average_gpa = (y.gpa_expected + y.gpa_overall) / 2
if gpa >= average_gpa:
try:
unranked_matches.index(y)
print "School already added"
except ValueError:
unranked_matches.append(y)
print "School added"
else:
print "GPA too low"
if pcat >= y.min_pcat:
try:
unranked_matches.index(y)
print "School already added"
except ValueError:
unranked_matches.append(y)
print "School added"
else:
print "PCAT too low"
if state.lower() == y.state.lower():
try:
unranked_matches.index(y)
print "School already added"
except ValueError:
unranked_matches.append(y)
print "School added"
else:
print "School out of state"
except KeyError:
print "City and state missing"
except KeyError:
return render('You must enter both GPA & PCAT scores')
else:
return render_to_response('index.html', {'error' : 'PCAT and GPA values are required.', 'form' : parameter_form})
return render_to_response('results.html', {'ranked_matches' : ranked_matches, 'unranked_matches' : unranked_matches}, context_instance = RequestContext(request))
我很难过为什么这个异常会引发shell而不是我的视图？感谢所有帮助。
答案 0 :(得分：0)
正如shavenwarthog所说，城市似乎是一个空字符串，这就是为什么不提出异常的原因。
如果你想在城市为空时引发错误，你可以：
required=False（但我想这不是您想要的）if not form.data['city'] # returns False if string is empty 答案 1 :(得分：0)
我能够解决这个问题如下：
if len(parameter_form.data['city']) != 0:
检查string的长度是否为0。
答案 2 :(得分：0)
我没有让Django安装ATM，所以我无法尝试我的假设，但您必须致电form.is_valid()填写.data属性：
>>> parameters = {'pcat' : 70, 'gpa' : 3.5, 'state' : 'TX'}
>>> form = ParameterForm(parameters)
>>> form.is_valid()
>>> form.data['city']
''