Python Web Scraping Cookbook

How it works

The following is the implementation of the .extension_from_contenttype property:

@propertydef extension_from_contenttype(self):    self.ensure_response()    map = const.ContentTypeToExtensions()    if self.contenttype in map:        return map[self.contenttype]    return None

The first line ensures that we have read the response from the URL. The function then uses a python dictionary, defined in the const module, which contains a dictionary of content-types to extension:

def ContentTypeToExtensions():    return {        "image/jpeg": ".jpg",        "image/jpg": ".jpg",        "image/png": ".png"    }

If the content type is in the dictionary, then the corresponding value will be returned. Otherwise, None is returned.

Note the corresponding property, .extension_from_url