I am trying to produce a list of categories that I can pass to my html template to render a nav bar of all the categories. In the products collection in my mongo data base, every product has a category field. Using the code below I generate a pymongo cursor of all the categories.
categories = Database.DATABASE[ProductConstants.COLLECTION].find({}, {'category': True, '_id': False})
print(categories)
<pymongo.cursor.Cursor at 0x1049cc668>
Putting categories in a list gives me
categories = list(categories)
print(categories)
[{'category': 'Phones'},
{'category': 'Phones'},
{'category': 'Phones'},
{'category': 'Phones'},
{'category': 'Phones'},
{'category': 'Soaps'}]
This seems to be a step in the right direction. I would like the end output for categories to simply be:
print(categories)
['Phones', 'Soaps'].
I have tried doing this:
categories = [category.values() for category in categories]
print(categories)
[dict_values(['Phones']),
dict_values(['Phones']),
dict_values(['Phones']),
dict_values(['Phones']),
dict_values(['Soaps'])]
If I could get rid of the dict_values I could potentially flatten this list using sum(categories, []) and then put that into a set() such that I don't have any duplicates. I believe this would give me the desired result but am not sure how to go about it. Perhaps I am going down the wrong route and there is a better way to go about all of this? Advice would be appreciated.
It sounds like you need a set of categories:
categories = [{'category': 'Phones'},
{'category': 'Phones'},
{'category': 'Phones'},
{'category': 'Phones'},
{'category': 'Phones'},
{'category': 'Soaps'}]
# use a set to eliminate the duplicate categories
c = set(d['category'] for d in categories)
print(list(c))
Output:
['Soaps', 'Phones']
Update:
c = {d['category'] for d in categories} # equivalent using a set comprehension
Try this
categories = Database.DATABASE[ProductConstants.COLLECTION].find({}, {'category': True, '_id': False}).distinct('category')
print categories
This category list will contains the distinct number of category values.
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