Question

I have a large data set of numbers which are embedded in documents. I want to extract them all, put them in an ordered list, and then return to each document its “pvalue”: which is its order in the sorted list divided by the length of the list.
I am having a lot of trouble figuring out how to do this within a python code.

movie_records = db.movies.find()
list=[]

for i in movie_records:
    num = i["total_tickets"]

    #put them all in a list, order the list


for i in movie_records:
    number=i["total_tickets"]
    tickets_pvalue= 1 - ( #position of number /len(list) )
    shows.update({"id":i["id"]}, {'$set':{"total_tickets_pvalue":tickets_pvalue}})

Answer 1

Barring any knowledge of mongodb (you’d be better off doing the sorting by it, as suggested in the comments):

movie_records = sorted([(m['total_tickets'], m) for m in db.movies.find()])

# Select distinct on total_tickets
distinct_records = []
prev = None
while movie_records:
    record = movie_records.pop(0)
    if record[0] != prev:
        prev = record[0]
        distinct_records.append(record[1])

for index, movie in enumerate(distinct_records):
    tickets_pvalue = 1 - (index + 1.0) / len(distinct_records)
    shows.update({"id": movie["id"]},
                 {'$set': {"total_tickets_pvalue": tickets_pvalue}})