CODEWITHSUNDEEP
pythonlistdictionarynestedfor-in-loop
Austin Johnson
Austin Johnson

Reputation: 747

Why does updating a dictionary remove the rest of the dictionaries from my nested array?

I have a json file with players structured as so

[
  {
    "Player_Name": "Rory McIlroy",
    "Tournament": [
      {
        "Name": "Arnold Palmer Invitational presented by Mastercard",
        "Points": "68.10",
        "Salary": "12200.00"
      },
      {
        "Name": "World Golf Championships-Mexico Championship",
        "Points": "103.30",
        "Salary": "12200.00"
      },
      {
        "Name": "The Genesis Invitational",
        "Points": "88.60",
        "Salary": "12200.00"
      },
      {
        "Name": "Farmers Insurance Open",
        "Points": "107.30",
        "Salary": "12200.00"
      },
      {
        "Name": "World Golf Championships-HSBC Champions",
        "Points": "138.70",
        "Salary": "12400.00"
      },
      {
        "Name": "The ZOZO Championship",
        "Points": "103.40",
        "Salary": "12300.00"
      }
    ]
  }]

When I run this code

import json
import numpy as np
import pandas as pd
from itertools import groupby

# using json open the player objects file and set it equal to data
with open('Active_PGA_Player_Objects.json') as json_file:
    data = json.load(json_file)

with open('Players_DK.json') as json_file:
    Players_DK = json.load(json_file)

results = []

for k,g in groupby(sorted(data, key=lambda x:x['Player_Name']), lambda x:x['Player_Name']): 
    results.append({'Player_Name':k, 'Tournament':[i['Tournament'][0] for i in g]})

for obj in results:
    for x in Players_DK:
        if obj['Player_Name'] == x['Name']:
            obj['Average'] = x['AvgPointsPerGame']

i = 0
points_results = []
while i < len(results):
    j = 0
    while j < len(results[i]['Tournament']):
        difference =  (int(float(results[i]['Tournament'][j]['Points'])) -  (results[i]['Average']))
        points_results.append(round(difference,2))
        j += 1
    i += 1

with open('PGA_Player_Objects_w_Average.json', 'w') as my_file:
    json.dump(results, my_file)

my list comes back like this

[{
    "Player_Name": "Rory McIlroy",
    "Tournament": [
      {
        "Name": "Arnold Palmer Invitational presented by Mastercard",
        "Points": "68.10",
        "Salary": "12200.00"
      }
    ],
    "Average": 96.19
  }]

Can someone explain to me why when I update the specific dictionary it deletes all but the first value from the nested Tournament list? My goal here is to add each players average to their corresponding dictionary so that I can take each average and subtract it from each score. When I try to do this though I'm only able to perform it on the one value left in the list.

Upvotes: 1

Views: 50

Answers (1)

pythomatic
pythomatic

Reputation: 657

Just for what it's worth, I'd go back and really think about what each line is really doing. You're also making things harder on yourself by calling variables obj or x. Calculating the average can be done like:

for player in data: # data is poorly named, try players or players_data
    player['Average'] = sum(float(tourny['Points']) for tourny in player['Tournament']) / len(player['Tournament'])
    for tourny in player['Tournament']:
        tourny['Difference'] = float(tourny['Points']) - float(player['Average'])

leaving you with:

{'Player_Name': 'Rory McIlroy', 
 'Tournament': [{
     'Name': 'Arnold Palmer Invitational presented by Mastercard', 
     'Points': '68.10', 
     'Salary': '12200.00', 
     'Difference': -33.46666666666667},
    {
     'Name': 'World Golf Championships-Mexico Championship', 
     'Points': '103.30', 
     'Salary': '12200.00', 
     'Difference': 1.7333333333333343}, # .....etc 
  'Average': 101.566666666666666
}

When you use names in your code that describe what they're representing, a huge number of optimizations become immediately obvious. Give it a go!

Upvotes: 2

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