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當我運行此如果塊：查詢數據存儲：「NoneType」對象沒有屬性
first_query = db.GqlQuery("SELECT * FROM Contract ORDER BY date DESC").get()
if first_query == None:
numBook = 42
numInitialPage = 42
numFinalPage = 42
first_record = Contract(book_number = 1, initial_page = 0, final_page = 0)
first_record.put()
contract = db.GqlQuery("SELECT * FROM Contract ORDER BY date DESC").get()
numBook = contract.book_number
numInitialPage = contract.final_page +1
numFinalPage = numInitialPage
else:
contract = first_query
numBook = first_query
numInitialPage = 51
numFinalPage = 51
過程跳轉到if塊，但是，後來，我收到此錯誤信息：
File "C:\Users\CG\Documents\udacity\contract\main.py", line 88, in get
numBook = contract.book_number
AttributeError: 'NoneType' object has no attribute 'book_number'
由於我用.put()來插入一條記錄，而.get()做了一個處理，爲什麼合同的價值是None？
在此先感謝您的幫助！
這裏整個代碼：
# -*- coding: utf-8 -*-
# -*- coding: utf-8 -*-
#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
import os
import webapp2
import jinja2
jinja_environment = jinja2.Environment(autoescape=True,
loader=jinja2.FileSystemLoader(os.path.join(os.path.dirname(__file__), 'templates')))
import re
from google.appengine.ext import db
USER_RE = re.compile(r"^[a-zA-Z0-9_ -]{3,20}$")
def valid_person(person):
return USER_RE.match(person)
PASS_RE = re.compile(r"^.{3,20}$")
def valid_SSN(SSN):
return PASS_RE.match(SSN)
EMAIL_RE = re.compile(r"^[\S][email protected][\S]+\.[\S]+$")
def valid_email(email):
return EMAIL_RE.match(email)
import time
import datetime
def dateToday():
today = datetime.datetime.today()
todayDay = str(today.day)
todayMonth = str(today.month)
monthExt = {'1':' January ', '2':'February', '3':' March ', '4':'April', '5':'May', '6':'June', '7':' July ', '8':'August', '9':'September', '10':'October', '11':'November ', '12':'December'}
todayYear = str(today.year)
return(todayDay + ' of ' + monthExt[todayMonth] + ' of ' + todayYear)
class Person(db.Model):
firstName = db.StringProperty(required = True)
nacionality = db.StringProperty(required = True)
marital_status = db.StringProperty(required = True)
profession = db.StringProperty(required = True)
SSN = db.IntegerProperty(required = True)
driver_license = db.IntegerProperty(required = True)
# address = db.PostalAddress(required = False)
class Contract(db.Model):
book_number = db.IntegerProperty(required = True)
initial_page = db.IntegerProperty(required = True)
final_page = db.IntegerProperty(required = True)
## contrac_type = db.StringProperty(required = False, choices=set(["Purchase Agreement", "Rental House", "Rental Car"]))
## contract_place = db.StringProperty(required = False)
## contract_date = db.DateProperty (required = True, auto_now = True, auto_now_add = True)
class ContractingParty(db.Model):
person = db.ReferenceProperty(Person, required=True, collection_name="party_to_contracts")
condition = db.StringProperty(required = False, choices=set(["buyer", "seller", "renter", "owner", "witness"]))
class MainHandler(webapp2.RequestHandler):
def get(self):
first_query = db.GqlQuery("SELECT * FROM Contract ORDER BY date DESC").get()
if first_query == None:
numBook = 8
numInitialPage = 8
numFinalPage = 8
first_record = Contract(book_number = 1, initial_page = 0, final_page = 0)
first_record.put()
contract = db.GqlQuery("SELECT * FROM Contract ORDER BY date DESC").get()
numBook = contract.book_number
numInitialPage = contract.final_page +1
numFinalPage = numInitialPage
else:
contract = first_query
numBook = first_query
numInitialPage = 7
numFinalPage = 7
## numBook = contract.book_number
## numInitialPage = contract.final_page +1
## numFinalPage = numInitialPage
template_values = {"person": "",
"nacionality": "",
"SSN": "",
"driverLicense": "",
"email":"",
"person_error": "",
"SSN_error": "",
"driverLicense_error": "",
"address": "",
"email_error": "",
"numBook": numBook,
"numInitialPage": numInitialPage,
"numFinalPage": numFinalPage,
}
template = jinja_environment.get_template('index.html')
self.response.out.write(template.render(template_values))
def post(self):
person_name = self.request.get("person")
user_nacionality = self.request.get('nacionality')
user_profession = self.request.get('profession')
user_maritalStatus = self.request.get('maritalStatus')
user_SSN = self.request.get('SSN')
user_email = self.request.get('email')
user_driverLicense = self.request.get('driverLicense')
person_error = ""
SSN_error = ""
driverLicense_error = ""
geted_email_error = ""
address = self.request.get('address')
contractType = self.request.get("contractType")
owner = self.request.get("owner")
witness = self.request.get("witness")
numBook = self.request.get("numBook")
numInitialPage = self.request.get("numInitialPage")
numFinalPage = self.request.get("numFinalPage")
if (person_name and valid_person(person_name)) and (user_SSN and valid_SSN(user_SSN)) and ((not user_email) or (user_email and valid_email(user_email))):
contract_record = Contract(book_number = numBook, initial_page = numInitialPage, final_page = numFinalPage)
contract_record.put()
contract_id = contract_record.key().id()
person_record = Person(name = person_name,
nacionality = user_nacionality,
profession = user_profession,
marital_status = user_maritalStatus,
SSN = int(user_SSN),
driverLicense = int(user_driverLicense))
person_record.put()
# HERE THE PROBLEM - Contracting party should be a table with ID refering to contract table
# contracting_party_record = ContractingParty(person = 1, )
## person = db.ReferenceProperty(People, required=True, collection_name="party_to_contracts")
## condition = db.StringProperty(required = False, choices=set(["buyer", "seller", "renter", "owner", "witness"]))
## self.redirect('/your_contract?person=%s&nacionality=%s&profession=%s&maritalStatus=%s&SSN=%s&driverLicense=%s&email=%s&witness=%s&owner=%s&contractType=%s&address=%s&numBook=%s&numInitialPage=%s&numFinalPage=%s' % (person_name, user_nacionality, user_profession, user_maritalStatus, user_SSN, user_driverLicense, user_email,
##witness, owner, contractType, address, numBook, numInitialPage, numFinalPage))
self.redirect('/your_contract?person=%s' % contract_id)
else:
if not person_name or not valid_person(person_name):
person_error = "Oh no!!! this person name isn't valid!"
if not user_SSN or not valid_SSN(user_SSN):
SSN_error = "Oh no!!! SSN isn't valid!"
if user_email and not valid_email(user_email):
geted_email_error = "Oh no!!! e-mail isn't valid!"
template_values = {"person": person_name,
"nacionality": user_nacionality,
"maritalStatus": user_maritalStatus,
"profession": user_profession,
"SSN": user_SSN,
"driverLicense": user_driverLicense,
"email": user_email,
"person_error": person_error,
"SSN_error": SSN_error,
"driverLicense_error": user_driverLicense,
"address": address,
"email_error": geted_email_error}
template = jinja_environment.get_template('index.html')
self.response.out.write(template.render(template_values))
class your_contractHandler(webapp2.RequestHandler):
def get(self):
contract_id = self.request.get('contract_id')
contract = db.GqlQuery("SELECT * FROM Contract WHERE __key__ = KEY('Model', contract_id").get()
## SELECT * FROM Model where __key__ = KEY('Model', <numeric_id>)
geted_numBook = contract.book_number
geted_numInitialPage = contract.initial_page
geted_numFinalPage = contract.final_page
geted_dateToday = dateToday()
geted_contractType = contract.contract_type
person = db.GqlQuery("SELECT * FROM Person ORDER BY date DESC").get()
geted_person_name = person.name
geted_user_nacionality = person.nacionality
geted_user_profession = person.profession
geted_user_maritalStatus = person.marital_status
geted_user_SSN = person.SSN
geted_user_driver_license = person.driver_license
your_contract = jinja_environment.get_template('your_contract.html')
your_contract_values = {"person":geted_person_name,
"nacionality":geted_user_nacionality,
"maritalStatus": geted_user_marital_status,
"profession": geted_user_profession,
"SSN":geted_user_SSN,
"driverLicense":geted_user_driver_license,
"address":geted_address,
"email":geted_user_email,
"contractType":geted_contract_type,
"dateContract":geted_dateToday,
"numBook":geted_numBook,
"numInitialPage":geted_numInitialPage,
"numFinalPage":geted_numInitialPage,
}
template = jinja_environment.get_template('index.html')
self.response.out.write(your_contract.render(your_contract_values))
# ContractingParty.all().ancestor(thecontract).run()
# contract_id = contract.key().id()
# contract_parties = Contract.get_by_id(contract_id)
#http://stackoverflow.com/questions/11294526/how-to-model-a-contract-database-with-several-buyers-or-sellers-using-gae-data
#http://stackoverflow.com/questions/11311461/how-to-query-gae-datastore-to-render-a-template-newbie-level
app = webapp2.WSGIApplication([('/', MainHandler), ('/your_contract', your_contractHandler)],
debug=True)
謝謝，@NedBatchelder，剛剛完成！ – craftApprentice 2012-07-09 02:43:15
它在[GAE文檔]（https://developers.google.com/appengine/docs/python/datastore/gqlqueryclass#GqlQuery_get）中說，如果沒有找到結果，'GqlQuery.get（）'返回'None'。 – 2012-07-09 02:48:44
問題是：如果我只是把合同寫入一個新記錄，怎麼會有沒有結果：'first_record = Contract（book_number = 1，initial_page = 0，final_page = 0） first_record.put（）'？ – craftApprentice 2012-07-09 02:53:37