def get_top_bot(count, db=None):
"""Get ``count`` top and bottom traders.
Parameters
----------
count : int
Number of top/bottom traders to get.
Returns
-------
top_bot : dict
A dict containing three keys: ``count``, ``top``, and ``bottom``.
* ``count`` is the number of top and bottom traders.
* ``top`` and ``bottom`` a tuple containing ``count`` dicts, each
containing the keys:
* ``id``: Trader ID.
* ``turnover``: Total turnover for the trader.
* ``profit``: Profit relative to base price of products bought.
If there are fewer traders than ``count``, the lists are shorter than
``count``.
"""
# get data from DB
if db is None:
db = Database.default()
buyers = db.buyer_dict()
orders = db.read_all_orders()
# parse orders
traders = {} # list of traders
for order in orders:
# Order fields
# oid : order id
# bid : buyer id
# code : product code
# pid : price id
# rel_cost : relative cost from product base price
# abs_cost : absolut cost the buyer paid
# timestamp : order timestamp
oid, bid, code, pid, rel_cost, abs_cost, timestamp = order
# add data
if bid not in traders:
traders[bid] = {
'id': bid,
'name': buyers[bid],
'turnover': 0,
'profit': 0,
}
traders[bid]['turnover'] += abs_cost
traders[bid]['profit'] += -rel_cost
# construct the list
traders = sorted(traders.values(), key=(lambda trader: trader['profit']), reverse=True)
# data!
return {
'count': min(count, len(traders)),
'top': tuple(traders[0:count]),
'bottom': tuple(traders[-count:][::-1]),
}
def before_request():
g.db = Database.default()
