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pythonurllib2

Python urllib2.HTTPError: HTTP Error 503: Service Unavailable on valid website

I have been using Amazon's Product Advertising API to generate urls that contains prices for a given book. One url that I have generated is the following:

http://www.amazon.com/gp/offer-listing/0415376327%3FSubscriptionId%3DAKIAJZY2VTI5JQ66K7QQ%26tag%3Damaztest04-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D386001%26creativeASIN%3D0415376327

When I click on the link or paste the link on the address bar, the web page loads fine. However, when I execute the following code I get an error:

url = "http://www.amazon.com/gp/offer-listing/0415376327%3FSubscriptionId%3DAKIAJZY2VTI5JQ66K7QQ%26tag%3Damaztest04-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D386001%26creativeASIN%3D0415376327"
html_contents = urllib2.urlopen(url)

The error is urllib2.HTTPError: HTTP Error 503: Service Unavailable. First of all, I don't understand why I even get this error since the web page successfully loads.

Also, another weird behavior that I have noticed is that the following code sometimes does and sometimes does not give the stated error:

html_contents = urllib2.urlopen("http://www.amazon.com/gp/offer-listing/0415376327%3FSubscriptionId%3DAKIAJZY2VTI5JQ66K7QQ%26tag%3Damaztest04-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D386001%26creativeASIN%3D0415376327")

I am totally lost on how this behavior occurs. Is there any fix or work around to this? My goal is to read the html contents of the url.

EDIT

I don't know why stack overflow is changing my code to change the amazon link I listed above in my code to rads.stackoverflow. Anyway, ignore the rads.stackoverflow link and use my link above between the quotes.

Solution

  • It's because Amazon don't allow automated access to their data, so they're rejecting your request because it didn't come from a proper browser. If you look at the content of the 503 response, it says:

    To discuss automated access to Amazon data please contact [email protected]. For information about migrating to our APIs refer to our Marketplace APIs at https://developer.amazonservices.com/ref=rm_5_sv, or our Product Advertising API at https://affiliate-program.amazon.com/gp/advertising/api/detail/main.html/ref=rm_5_ac for advertising use cases.

    This is because the User-Agent for Python's urllib is so obviously not a browser. You could always fake the User-Agent, but that's not really good (or moral) practice.

    As a side note, as mentioned in another answer, the requests library is really good for HTTP access in Python.