I have copied the code as is and ran the program.
shashwat.suman@shashwat-laptop:~/Desktop/ProWebscrapper$ scrapy runspider stackoverflow_spider.py -o top-stackoverflow-questions.json
2015-07-07 21:51:59 [scrapy] INFO: Scrapy 1.0.0.post2+g5303c66 started (bot: scrapybot)
2015-07-07 21:51:59 [scrapy] INFO: Optional features available: ssl, http11
2015-07-07 21:51:59 [scrapy] INFO: Overridden settings: {'FEED_FORMAT': 'json', 'FEED_URI': 'top-stackoverflow-questions.json'}
yoyo1
yoyo
2015-07-07 21:51:59 [scrapy] INFO: Enabled extensions: CloseSpider, FeedExporter, TelnetConsole, LogStats, CoreStats, SpiderState
2015-07-07 21:51:59 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, DefaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
2015-07-07 21:51:59 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
2015-07-07 21:51:59 [scrapy] INFO: Enabled item pipelines:
2015-07-07 21:51:59 [scrapy] INFO: Spider opened
2015-07-07 21:51:59 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2015-07-07 21:51:59 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023 yoyo2
2015-07-07 21:52:02 [scrapy] INFO: Closing spider (finished)
2015-07-07 21:52:02 [scrapy] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 250,
'downloader/request_count': 1,
'downloader/request_method_count/GET': 1,
'downloader/response_bytes': 29432,
'downloader/response_count': 1,
'downloader/response_status_count/200': 1,
'finish_reason': 'finished',
'finish_time': datetime.datetime(2015, 7, 7, 16, 22, 2, 371020),
'log_count/DEBUG': 2,
'log_count/INFO': 7,
'response_received_count': 1,
'scheduler/dequeued': 1,
'scheduler/dequeued/memory': 1,
'scheduler/enqueued': 1,
'scheduler/enqueued/memory': 1,
'start_time': datetime.datetime(2015, 7, 7, 16, 21, 59, 613620)}
2015-07-07 21:52:02 [scrapy] INFO: Spider closed (finished)
I have python 2.7.9 installed.