NameError: name 'result' is not defined. Can't figure out how to get the results to the next line

Question

I'm a complete beginner in Python, trying to get a script to work, but I'm a little at loss on where it goes wrong. From reading other posts it seems result hasn't been mentioned before and it doesn't know how to deal with the results. I'm running Python 2.7.11 on EL Capitan

python ytc.py -v YQHsXMglC9A [*] Retrieving video ID: YQHsXMglC9A [*]
Thumbnails retrieved. Now submitting to TinEye. [*] Searching TinEye
for: https://i.ytimg.com/vi/YQHsXMglC9A/default.jpg Traceback (most
recent call last):   File "ytc.py", line 72, in <module>
if result.total_results: NameError: name 'result' is not defined

This is the script:

import argparse
import requests
import json

from pytineye import TinEyeAPIRequest

tineye = TinEyeAPIRequest('http://api.tineye.com/rest/','PUBLICKEY','PRIVATEKEY')

youtube_key = "MY-API"

ap = argparse.ArgumentParser()
ap.add_argument("-v","--videoID",    required=True,help="The videoID of the YouTube video. For example: https://www.youtube.com/watch?v=VIDEOID")
args = vars(ap.parse_args())

video_id    = args['videoID']

#
# Retrieve the video details based on videoID
#
def youtube_video_details(video_id):

    api_url  = "https://www.googleapis.com/youtube/v3/videos?part=snippet%2CrecordingDetails&"
    api_url += "id=%s&" % video_id
    api_url += "key=%s" % youtube_key

    response = requests.get(api_url)

    if response.status_code == 200:

        results = json.loads(response.content)

        return results

    return None


print "[*] Retrieving video ID: %s" % video_id
video_data = youtube_video_details(video_id)

thumbnails = video_data['items'][0]['snippet']['thumbnails']

print "[*] Thumbnails retrieved. Now submitting to TinEye."

url_list = []

# add the thumbnails from the API to the list
for thumbnail in thumbnails:

    url_list.append(thumbnails[thumbnail]['url'])


# build the manual URLS
for count in range(4):

    url = "http://img.youtube.com/vi/%s/%d.jpg" % (video_id,count)

    url_list.append(url)


results = []

# now walk over the list of URLs and search TinEye
for url in url_list:

    print "[*] Searching TinEye for: %s" % url

    try:
        result = tineye.search_url(url)
    except:
        pass

    if result.total_results:
        results.extend(result.matches)

result_urls = []
dates       = {}

for match in results:

    for link in match.backlinks:

        if link.url not in result_urls:

            result_urls.append(link.url)
            dates[link.crawl_date] = link.url

print            
print "[*] Discovered %d unique URLs with image matches." % len(result_urls)

for url in result_urls:

    print url


oldest_date = sorted(dates.keys())

print
print "[*] Oldest match was crawled on %s at %s" % (str(oldest_date[0]),dates[oldest_date[0]])

Answer 1

If the try-except fails, it will execute the except block which has only pass, no assignment of variable result, so if that's the case, on if result.total_results, you are referencing an object which does not exist.

This should be a quick fix

try:
    result = tineye.search_url(url)
except NameError:
    print 'Nothing Found !'
    break

if result.total_results:
    results.extend(result.matches)

Answer 2

The error is clear, result variable is used while its not defined. this happen in the case of failure in your try except instruction.

Fix it by moving the instruction into the try block :

for url in url_list:
    print "[*] Searching TinEye for: %s" % url
    try:
        result = tineye.search_url(url)
        if result.total_results:
            results.extend(result.matches)
    except:
        pass