Berechnungsschleife Python-Score-Datei

Question

Modifiziert:

Mit den Noten Datei folgenden Schüler, wie würde ich die Daten laden und score1, score3 in Python zusammenfassen?

{"id": "1","student":"John", "dt": "1997-01-01 07:00:02", "score1": "38.28"} 
{"id": "2", "student":"Jane", "dt": "1997-01-01 07:00:02", "score1": "32.35"} 
{"id": "3", "student":"Richard", "dt": "1997-01-10 10:00:00", "score3": "22.92"} 

Ausgang:

score1: 70.63 
score3: 22.92 

Answer 1

datei.txt:

{"id": "1","student":"John", "dt": "1997-01-01 07:00:02", "score1": "38.28"} 
{"id": "2", "student":"Jane", "dt": "1997-01-01 07:00:02", "score1": "32.35"} 
{"id": "3", "student":"Richard", "dt": "1997-01-10 10:00:00", "score3": "22.92"} 

Do:

import json 

scores = dict() 
with open('file.txt') as filename: 
    for line in filename.readlines(): 
     data = json.loads(line) 
     score = [key for key in data.keys() if key.startswith('score')] 
     if len(score) == 0: 
      continue 
     score = score[0] 
     if score not in scores: 
      scores[score] = 0 
     scores[score] += float(data[score]) 

for k, v in scores.items(): 
    print('{}: {}'.format(k, v)) 

Ouput:

score1: 70.63 
score3: 22.92 

Answer 2

Mit der integrierten Bibliothek json können Sie JSON in Python-Objekte dekodieren. Wenn Sie diese Daten verwenden:

[ 
    {"id": "1","student":"John", "dt": "1997-01-01 07:00:02", "score1": "38.28"}, 
    {"id": "2", "student":"Jane", "dt": "1997-01-01 07:00:02", "score1": "32.35"}, 
    {"id": "3", "student":"Richard", "dt": "1997-01-10 10:00:00", "score3": "22.92"} 
] 

Notiere die [...] und , in den Daten, so dass es als eine Liste lädt.

Dann könnte das Skript unten die Aufgabe erledigen.

import json 
from math import fsum 

data = json.load(open("data.json")) # Load the data 
sums = {} 
for person in data: # Loop over pieces of data 
    # Add any names starting with "score" to sums 
    for key in person.keys(): # Loop over names 
     if not key[:5] == "score": 
      continue # No, not starting with score, skip it 
     # Use math.fsum to add the value known to the score, and set it. 
     sums[key] = fsum([sums.get(key, 0.0), float(person[key])]) 
for k, v in sums.items(): 
    # Print out the data 
    print("%s: %.02f" % (k, v)) 

Ich habe Erklärungen in den Kommentaren. Getestet in IDLE 3.6.1.