我很难让一个简单的Hello World应用程序使用Flask、MongoDB和Python工作。当尝试从bson
模块导入时,应用程序会爆炸。所有模块都是通过pip
成功安装的,而且我是在virtualenv
中运行的,所以我不确定为什么会收到这个错误:ImportError: cannot import name BSON
下面是我的示例应用程序代码:
import os
from flask import Flask
from flask import g
from flask import jsonify
from flask import json
from flask import request
from flask import url_for
from flask import redirect
from flask import render_template
from flask import make_response
import pymongo
from pymongo import Connection
from bson import BSON
from bson import json_util
app = Flask(__name__)
@app.route('/')
def hello():
connection = Connection()
# Get your DB
db = connection.my_database
# Get your collection
cars = db.cars
# Create some objects
import datetime
car = {"brand": "Ford",
"model": "Mustang",
"date": datetime.datetime.utcnow()}
# Insert it
cars.insert(car)
json_docs = [json.dumps(doc, default=json_util.default) for doc in cars.find()]
return json_docs
if __name__ == '__main__':
# Bind to PORT if defined, otherwise default to 5000.
port = int(os.environ.get('PORT', 5000))
app.debug = True
app.run(host='0.0.0.0', port=port)
我不确定如何进行调试,或者我是否在这里遗漏了什么。
编辑:pip freeze
的结果
Flask==0.9
Jinja2==2.6
WTForms==1.0.2
Werkzeug==0.8.3
bson==0.3.3
distribute==0.6.28
mongo==0.2.0
pymongo==2.3
pytz==2012g
wsgiref==0.1.2
Edit2:删除bson和pymongo,重新运行pip install pymongo
。立即完成跟踪:
Traceback (most recent call last):
18:21:20 web.1 | File ".../venv/lib/python2.7/site-packages/flask/app.py", line 1701, in __call__
18:21:20 web.1 | return self.wsgi_app(environ, start_response)
18:21:20 web.1 | File ".../venv/lib/python2.7/site-packages/flask/app.py", line 1689, in wsgi_app
18:21:20 web.1 | response = self.make_response(self.handle_exception(e))
18:21:20 web.1 | File ".../venv/lib/python2.7/site-packages/flask/app.py", line 1687, in wsgi_app
18:21:20 web.1 | response = self.full_dispatch_request()
18:21:20 web.1 | File ".../venv/lib/python2.7/site-packages/flask/app.py", line 1361, in full_dispatch_request
18:21:20 web.1 | response = self.make_response(rv)
18:21:20 web.1 | File ".../venv/lib/python2.7/site-packages/flask/app.py", line 1450, in make_response
18:21:20 web.1 | rv = self.response_class.force_type(rv, request.environ)
18:21:20 web.1 | File ".../venv/lib/python2.7/site-packages/werkzeug/wrappers.py", line 711, in force_type
18:21:20 web.1 | response = BaseResponse(*_run_wsgi_app(response, environ))
18:21:20 web.1 | File ".../venv/lib/python2.7/site-packages/werkzeug/test.py", line 818, in run_wsgi_app
18:21:20 web.1 | app_iter = app(environ, start_response)
18:21:20 web.1 | TypeError: 'list' object is not callable
发布于 2012-10-20 07:13:04
尝试卸载bson
和pymongo
软件包,然后重新安装pymongo
软件包。pymongo
安装了自己的bson
包,我认为您已经用其他bson
包安装覆盖了它,这可能是导致导入错误的原因。
仅供参考:
site-packages
发布于 2017-09-12 08:17:35
我也遇到了同样的问题。我想原因是我先安装了pymongo
,然后再安装bson
。然后我卸载bson。然后我就遇到了这个问题。
pip freeze pymongo
它不需要任何东西。
所以也许它有自己的bson包。
我解决这个问题的方法是:
pip uninstall pymongo
pip uninstall bson
然后重新安装pymongo
pip install pymongo
发布于 2012-10-20 07:30:47
您在hello()
中返回一个列表。您需要返回一个字符串或响应对象,请参阅Flask docs。例如,在返回前将列表转换为字符串:
return '\n'.join(json_docs)
https://stackoverflow.com/questions/12983472
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