全局变量和python flask

小编典典

全局变量和python flask

flask

我想做的只是显示来自一个API的firstevent。该变量称为“ firstevent”，其值应显示在网页上。但是firstevent在def内部，因此我将其更改为全局变量，希望可以在不同的函数中使用。但是它显示“ NameError：未定义全局名称’firstevent’”。这就是我在做什么：

定义一个全局变量

global firstevent

发送此变量一个随机值，应该是 events['items'][1]['end']

firstevent = 1

在网站上显示firstevent的价值。

@app.route("/")
def index():
    return 'User %s' % firstevent

我不确定现在正在发生什么，也许这是范围问题？我已经在线检查了许多答案，但仍然找不到解决方案。

这是详细信息（不是整个代码）

import os

# Retrieve Flask, our framework
# request module gives access to incoming request data
import argparse
import httplib2
import os
import sys
import json

from flask import Flask, request
from apiclient import discovery
from oauth2client import file
from oauth2client import client
from oauth2client import tools

from apiclient.discovery import build
from oauth2client.client import OAuth2WebServerFlow

import httplib2

global firstevent  
app = Flask(__name__)

def main(argv):
  # Parse the command-line flags.
  flags = parser.parse_args(argv[1:])

  # If the credentials don't exist or are invalid run through the native client
  # flow. The Storage object will ensure that if successful the good
  # credentials will get written back to the file.
  storage = file.Storage('sample.dat')
  credentials = storage.get()
  if credentials is None or credentials.invalid:
    credentials = tools.run_flow(FLOW, storage, flags)

  # Create an httplib2.Http object to handle our HTTP requests and authorize it
  # with our good Credentials.
  http = httplib2.Http()
  http = credentials.authorize(http)

  # Construct the service object for the interacting with the Calendar API.
  calendar = discovery.build('calendar', 'v3', http=http)
  created_event = calendar.events().quickAdd(calendarId='XXXX@gmail.com', text='Appointment at Somewhere on June 3rd 10am-10:25am').execute()
  events = calendar.events().list(calendarId='XXXX@gmail.com').execute()
  #firstevent = events['items'][1]['end']

  firstevent = 1
  #print events['items'][1]['end']

 # Main Page Route
@app.route("/")
def index():
    return 'User %s' % firstevent


# Second Page Route
@app.route("/page2")
def page2():
  return """<html><body>
  <h2>Welcome to page 2</h2>
    <p>This is just amazing!</p>
    </body></html>"""


# start the webserver
if __name__ == "__main__":
    app.debug = True
    app.run()

阅读 468

2020-04-07

共1个答案

小编典典

是的，这是一个范围问题。在main()函数的开头，添加以下内容：

global firstevent

那应该做。在函数内部未定义的任何变量都是全局变量。你可以从任何功能直接访问它。但是，要修改变量，你需要global var在函数中编写。

例

这将在函数上创建局部变量“ firstevent”：

firstevent = 0
def modify():
    firstevent = 1

这会修改全局变量“ firstevent”

firstevent = 0
def modify():
    global firstevent
    firstevent = 1

2020-04-07