Python בדוגמאות קוד של App Engine

דוגמאות קוד Python הבאות מדגימות איך להשתמש ב-App Engine כדי לבצע קריאות ל-YouTube Data API (גרסה 3). אפשר להוריד את דוגמאות הקוד האלה ממאגרים לדוגמה של קוד Python ב-Google App Engine ב-GitHub.

דרישות מוקדמות

כדי להריץ את דוגמאות הקוד שבהמשך, צריך להגדיר פרויקט ב-Google API Console ולקבל מפתח API. נכון לעכשיו, בכל פרויקט מוגדר משתנה API_KEY שמוגדר לערך REPLACE_ME. כדי להריץ את הדוגמאות אתם צריכים להחליף את הערך הזה במפתח API משלכם.

חשוב: כדי להריץ את כל הדוגמאות האלה, צריך להפעיל את YouTube Data API (גרסה 3) ואת Freebase API בפרויקט שמשויך למפתח ה-API. אם האפליקציה שלך ניגשת לנתונים פרטיים של משתמשים או ערוצים, נדרש גם מזהה לקוח OAuth 2.0.

דוגמאות קוד

חיפוש לפי מילת מפתח

דוגמת הקוד שבהמשך מפעילה את השיטה search.list של ה-API כדי לאחזר תוצאות חיפוש המשויכות למילת מפתח מסוימת.

import os
import urllib
import webapp2
import jinja2

from apiclient.discovery import build
from optparse import OptionParser

JINJA_ENVIRONMENT = jinja2.Environment(
    loader=jinja2.FileSystemLoader(os.path.dirname(__file__)),
    extensions=['jinja2.ext.autoescape'])

# Set DEVELOPER_KEY to the "API key" value from the Google Developers Console:
# https://console.developers.google.com/project/_/apiui/credential
# Please ensure that you have enabled the YouTube Data API for your project.
DEVELOPER_KEY = "REPLACE_ME"
YOUTUBE_API_SERVICE_NAME = "youtube"
YOUTUBE_API_VERSION = "v3"

class MainHandler(webapp2.RequestHandler):
   
   def get(self):
        if DEVELOPER_KEY == "REPLACE_ME":
          self.response.write("""You must set up a project and get an API key
                                 to run this project.  Please visit 
				 <landing page> to do so."""
        else:
          youtube = build(
            YOUTUBE_API_SERVICE_NAME, 
            YOUTUBE_API_VERSION, 
            developerKey=DEVELOPER_KEY)
          search_response = youtube.search().list(
            q="Hello",
            part="id,snippet",
            maxResults=5
          ).execute()
        
          videos = []
          channels = []
          playlists = []
        
          for search_result in search_response.get("items", []):
            if search_result["id"]["kind"] == "youtube#video":
                videos.append("%s (%s)" % (search_result["snippet"]["title"], 
                  search_result["id"]["videoId"]))
            elif search_result["id"]["kind"] == "youtube#channel":
                channels.append("%s (%s)" % (search_result["snippet"]["title"], 
                  search_result["id"]["channelId"]))
            elif search_result["id"]["kind"] == "youtube#playlist":
                playlists.append("%s (%s)" % (search_result["snippet"]["title"], 
                  search_result["id"]["playlistId"]))
        
          template_values = {
           'videos': videos,
           'channels': channels,
           'playlists': playlists
          }
       
	  self.response.headers['Content-type'] = 'text/plain' 
          template = JINJA_ENVIRONMENT.get_template('index.html')
          self.response.write(template.render(template_values))
        
app = webapp2.WSGIApplication([
  ('/.*', MainHandler),
], debug=True)

חיפוש לפי נושא

דוגמת הקוד שבהמשך מפעילה את השיטה search.list של ה-API כדי לאחזר תוצאות חיפוש המשויכות לנושא מסוים של Freebase.

import os
import urllib
import webapp2
import jinja2

from apiclient.discovery import build
from optparse import OptionParser

import json

JINJA_ENVIRONMENT = jinja2.Environment(
    loader=jinja2.FileSystemLoader(os.path.dirname(__file__)),
    extensions=['jinja2.ext.autoescape'])

REGISTRATION_INSTRUCTIONS = """
    You must set up a project and get an API key to run this code. Please see
    the instructions for creating a project and a key at <a
    href="https://developers.google.com/youtube/registering_an_application"
    >https://developers.google.com/youtube/registering_an_application</a>.
    <br><br>
    Make sure that you have enabled the YouTube Data API (v3) and the Freebase
    API for your project."""

# Set API_KEY to the "API key" value from the Google Developers Console:
# https://console.developers.google.com/project/_/apiui/credential
# Please ensure that you have enabled the YouTube Data API and Freebase API
# for your project.
API_KEY = "REPLACE_ME"
YOUTUBE_API_SERVICE_NAME = "youtube"
YOUTUBE_API_VERSION = "v3"
FREEBASE_SEARCH_URL = "https://www.googleapis.com/freebase/v1/search?%s"
QUERY_TERM = "dog"

class MainHandler(webapp2.RequestHandler):

  def get(self):
    if API_KEY == 'REPLACE_ME':
      self.response.write(REGISTRATION_INSTRUCTIONS)
    else:
      # Present a list of Freebase topic IDs for the query term
      self.list_topics(QUERY_TERM)

  def list_topics(self, QUERY_TERM):
    # Retrieve a list of Freebase topics associated with the query term
    freebase_params = dict(query=QUERY_TERM, key=API_KEY)
    freebase_url = FREEBASE_SEARCH_URL % urllib.urlencode(freebase_params)
    freebase_response = json.loads(urllib.urlopen(freebase_url).read())

    if len(freebase_response["result"]) == 0:
      exit("No matching terms were found in Freebase.")

    # Create a page that shows a select box listing the topics.
    # When the user selects a topic and submits the form, the
    # 'post' method below will handle the form submission and
    # retrieve videos for the selected topic.
    select_topic_page = ('''
        <html>
          <body>
            <p>The following topics were found:</p>
            <form method="post">
              <select name="topic">
    ''')
    for result in freebase_response["result"]:
      select_topic_page += ('<option value="' + result["mid"] + '">' +
                            result.get("name", "Unknown") + '</option>')

    select_topic_page += '''
              </select>
              <p><input type="submit" /></p>
            </form>
          </body>
        </html>
    '''

    # Display the HTML page listing the topic choices.
    self.response.out.write(select_topic_page)

  def post(self):
    topic_id = self.request.get('topic')

    # Service for calling the YouTube API
    youtube = build(YOUTUBE_API_SERVICE_NAME,
                    YOUTUBE_API_VERSION,
                    developerKey=API_KEY)

    # Execute the search request using default query term and retrieved topic.
    search_response = youtube.search().list(
      part = 'id,snippet',
      type = 'video',
      topicId = topic_id
    ).execute()

    videos = []

    for search_result in search_response.get("items", []):
      videos.append(search_result)

    template_values = {
      'videos': videos
    }

    self.response.headers['Content-type'] = 'text/html'
    template = JINJA_ENVIRONMENT.get_template('index.html')
    self.response.write(template.render(template_values))

app = webapp2.WSGIApplication([
  ('/.*', MainHandler),
], debug=True)

אחזור העלאות של ערוץ

דוגמת הקוד שבהמשך מפעילה את השיטה playlistItems.list של ה-API כדי לאחזר רשימה של סרטונים שהועלו לערוץ ספציפי. ניתן לזהות את הערוץ לפי מזהה הערוץ או לפי שם הערוץ. הקוד גם מפעיל את השיטה channels.list כדי לאחזר את מזהה הפלייליסט שמזהה את הסרטונים שהועלו לערוץ.

import os
import urllib
import webapp2
import jinja2

from apiclient.discovery import build
from optparse import OptionParser

import json

JINJA_ENVIRONMENT = jinja2.Environment(
    loader=jinja2.FileSystemLoader(os.path.dirname(__file__)),
    extensions=['jinja2.ext.autoescape'])

REGISTRATION_INSTRUCTIONS = """
    You must set up a project and get an API key to run this code. Please see
    the instructions for creating a project and a key at <a
    href="https://developers.google.com/youtube/registering_an_application"
    >https://developers.google.com/youtube/registering_an_application</a>.
    <br><br>
    Make sure that you have enabled the YouTube Data API (v3) and the Freebase
    API for your project."""

# Set API_KEY to the "API key" value from the Google Developers Console:
# https://console.developers.google.com/project/_/apiui/credential
# Please ensure that you have enabled the YouTube Data API and Freebase API
# for your project.
API_KEY = "REPLACE_ME"
YOUTUBE_API_SERVICE_NAME = "youtube"
YOUTUBE_API_VERSION = "v3"
FREEBASE_SEARCH_URL = "https://www.googleapis.com/freebase/v1/search?%s"
QUERY_TERM = "dog"

class MainHandler(webapp2.RequestHandler):

  def get(self):
    if API_KEY == 'REPLACE_ME':
      self.response.write(REGISTRATION_INSTRUCTIONS)
    else:
      # Present a list of Freebase topic IDs for the query term
      self.request_channel()

  def request_channel(self):
    # Display a text box where the user can enter a channel name or
    # channel ID.
    select_channel_page = '''
        <html>
          <body>
            <p>Which channel's videos do you want to see?</p>
            <form method="post">
              <p>
                <select name="channel_type">
                  <option value="id">Channel ID</option>
                  <option value="name">Channel name</option>
                </select>  
                <input name="channel" size="30">
              </p>
              <p><input type="submit" /></p>
            </form>
          </body>
        </html>
    '''

    # Display the HTML page that shows the form.
    self.response.out.write(select_channel_page)

  def post(self):
    # Service for calling the YouTube API
    youtube = build(YOUTUBE_API_SERVICE_NAME,
                    YOUTUBE_API_VERSION,
                    developerKey=API_KEY)

    # Use form inputs to create request params for channel details
    channel_type = self.request.get('channel_type')
    channels_response = None
    if channel_type == 'id':
      channels_response = youtube.channels().list(
          id=self.request.get('channel'),
          part='snippet,contentDetails'
      ).execute()
    else:
      channels_response = youtube.channels().list(
          forUsername=self.request.get('channel'),
          part='snippet,contentDetails'
      ).execute()

    channel_name = ''
    videos = []

    for channel in channels_response['items']:
      uploads_list_id = channel['contentDetails']['relatedPlaylists']['uploads']
      channel_name = channel['snippet']['title']
      
      next_page_token = ''
      while next_page_token is not None:
        playlistitems_response = youtube.playlistItems().list(
            playlistId=uploads_list_id,
            part='snippet',
            maxResults=50,
            pageToken=next_page_token
        ).execute()

        for playlist_item in playlistitems_response['items']:
          videos.append(playlist_item)
          
        next_page_token = playlistitems_response.get('tokenPagination', {}).get(
            'nextPageToken')
        
        if len(videos) > 100:
          break

    template_values = {
      'channel_name': channel_name,
      'videos': videos
    }

    self.response.headers['Content-type'] = 'text/html'
    template = JINJA_ENVIRONMENT.get_template('index.html')
    self.response.write(template.render(template_values))

app = webapp2.WSGIApplication([
  ('/.*', MainHandler),
], debug=True)