I can't understand the magic happening in helpers.py
What is lookup.cache[]?
I know lookup is the name of our function. I tried to search online for cache function but couldn't get any leads.
I need to understand it to rectify my pset. It shows too many news results when a marker is clicked. Help!
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lookup.cache is a dictionary. It is used to store all news articles that already have been looked up earlier for that zipcode.
The reason to do this is twofold:
- It makes the application faster
- It reduces the amount of network traffic
Disadvantage of this approach:
- If you leave the application running over some longer period of time, you won't see the most recent news articles.
About your second question:
You will have to arrange that somehow in application.py.
You will often receive lots of news articles. If you only want to show 5 of them, make sure you only show 5.
And finally, to quote Cliff B:
If this answers your question, please click on the check mark to accept. Let's keep up on forum maintenance. ;-)
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Yes. lookup.cache is a dict. But it's declaration looks different. Is cache a unique function acting on dicts? Also, the dict was never initialized before. It messes up with my concept of dict.– pankajOct 27 '18 at 9:49
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Is caching happening automatically & we are just refering it? This was intention was my question.– pankajOct 27 '18 at 9:51
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The line
lookup.cache = {}creates an empty directory. The linelookup.cache[geo] = ...simply assigns a value into the dictionary for the keygeo. That value happens to be a list. Oct 27 '18 at 10:10 -
And finally, the list is created using List Comprehension. See docs.python.org/3/tutorial/… Oct 27 '18 at 10:11
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Oh, my bad. I am not very fluent with these lists. Thank you! This answers all my questions.– pankajOct 27 '18 at 10:23