May 2017
Beginner to intermediate
220 pages
5h 2m
English
Content preview from Python Web Scraping - Second Edition
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Performance
To further understand how increasing the number of threads and processes affects the time required when downloading, here is a table of results for crawling 500 web pages:
| Script | Number of threads | Number of processes | Time | Comparison with sequential | Errors Seen? |
| Sequential | 1 | 1 | 1349.798s | 1 | N |
| Threaded | 5 | 1 | 361.504s | 3.73 | N |
| Threaded | 10 | 1 | 275.492s | 4.9 | N |
| Threaded | 20 | 1 | 298.168s | 4.53 | Y |
| Processes | 2 | 2 | 726.899s | 1.86 | N |
| Processes | 2 | 4 | 559.93s | 2.41 | N |
| Processes | 2 | 8 | 451.772s | 2.99 | Y |
| Processes | 5 | 2 | 383.438s | 3.52 | N |
| Processes | 5 | 4 | 156.389s | 8.63 | Y |
| Processes | 5 | 8 | 296.610s | 4.55 | Y |
The fifth column shows the proportion of time in comparison to the base case of sequential downloading. We can see that the increase in performance is not ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.