Question

我知道，这个问题很愚蠢，可以在互联网上轻松搜索到。我做到了，但这没有帮助我。我正在使用适用于Python（3.7.1）的Google Calendar API

from dateutil.parser import parse as dtparse
from datetime import datetime as dt
from googleapiclient.discovery import build
from httplib2 import Http
from oauth2client import file, client, tools
# If modifying these scopes, delete the file token.json.
SCOPES = 'https://www.googleapis.com/auth/calendar.readonly'

start = '2018-12-26T10:00:00+01:00'   # Let's say your start value returns this as 'str'
tmfmt = '%d %B, %H:%M %p'


class Calendar():

    def getEvents(self):
        """Shows basic usage of the Google Calendar API.
        Prints the start and name of the next 10 events on the user's calendar.
        """
        # The file token.json stores the user's access and refresh tokens, and is
        # created automatically when the authorization flow completes for the first
        # time.
        store = file.Storage('token.json')
        creds = store.get()
        if not creds or creds.invalid:
            flow = client.flow_from_clientsecrets('credentials.json', SCOPES)
            creds = tools.run_flow(flow, store)
        service = build('calendar', 'v3', http=creds.authorize(Http()))

        # Call the Calendar API
        now = dt.utcnow().isoformat() + 'Z'  # 'Z' indicates UTC time
        events_result = service.events().list(calendarId='primary', timeMin=now,
                                              maxResults=10, singleEvents=True,
                                              orderBy='startTime').execute()
        events = events_result.get('items', [])
        if not events:
            print('No upcoming events found.')
        for event in events:
            start = event['start'].get('dateTime', event['start'].get('date'))
            stime = dt.strftime(dtparse(start), format=tmfmt)
            items = str(stime + event['summary'])
            print(items)
            return items

"""
 Tried aswell   str1 = ''.join(str(e) for e in items)
                return str1
"""


    def Events(self):
        print(self.getEvents())


x = Calendar()
x.Events()

我对其进行了修改，以便以人类可读的日期格式返回事件。无论如何，当我在print(stime + event['summary'])中getEvents()时，我得到一个正常的输出。当我尝试以其他功能打印它时（最后它应该显示在tkinter标签中），它要么不起作用，要么打印第一项或最后一项...

这是如何实现的？

Answer 1

返回列表是通过从字面上返回列表对象而不是多次调用return来实现的。

实际上，您的函数将在第一次遇到return语句时退出。例如：

>>> def func():
...     return 1
...     return 2
...     return 3
... 
>>> func()
1

我们没有[1, 2, 3]的列表-我们退出时遇到的是第一次遇到的返回值。

具体地说，您在循环内有一个返回值。这将导致该函数在此循环的第一次迭代中退出。

您对事件的循环可能想要看起来像这样：

ret = []
for event in events:
    # ... snip...
    ret.append(items)
return ret

您可能还想考虑重命名某些变量-例如，items仅指单个项目。

从函数返回列表

1 个答案: