completed mongodb pipeline homework

app.py

@@ -1 +1,47 @@
-# Your DB Code Here
+import pymongo
+import datetime
+from db import db
+
+# Number of entries of selling data grouped by isbn
+P1 = db.books_selling_data.aggregate([
+    { "$group" : { "_id" : "$isbn", "number of entries" : { "$sum" : 1 }}}
+    ])
+# print (list(P1))
+
+
+# For books with more than 15000 total copies sold, return all the titles in a single array
+P2 = db.books_selling_data.aggregate([
+    {"$group": {"_id": "$isbn", "copies" :{"$sum" : "$copies_sold"}}},
+    {"$match": {"copies":{"$gte":15000}}},
+    {"$lookup": { "from" : "books", "localField": "_id", "foreignField": "isbn", "as":">15000"}},
+    { "$project" : { ">15000.title" : 1, "_id" : 0 } }
+    ])
+# print(list(P2))
+
+
+# Find the number of books by John Doe, sorted by isbn (but isbn is not returned)
+P3 = db.books.aggregate([
+    { "$group" : { "_id" : "$isbn", "author" : { "$push" : "$author" }}},
+    {"$match": {"author":"John Doe"}},
+    {"$count": "JDbooks"}
+    ])
+# print(list(P3))
+
+
+# Return the price per book for each order
+P4 = db.books_selling_data.aggregate([
+    {"$addFields":{"price per book": {"$divide":["$total_price" , "$copies_sold"]}}},
+    {"$project":{"_id":0 , "order_id":1 , "price per book" : 1}}
+    ])
+# print(list(P4))
+
+
+# Return the average price per book for each order supplied from titan
+P5 = db.books_selling_data.aggregate([
+    {"$addFields":{"price per book": {"$divide":["$total_price" , "$copies_sold"]}}},
+    {"$project":{"_id":0 , "order_id":1 , "price per book" : 1, "supplier":1}},
+    {"$unwind" : "$supplier"},
+    {"$match": {"supplier":"titan"}}, 
+    {"$group":{"_id":"$supplier", "average price per book": {"$avg": "$price per book"}}}
+    ])
+print(list(P5))