Python Liste der Wörterbücher Listen Verständnis

Question

Ich habe eine Liste von Wörterbuch enthält Listen mit:

a = [{'alpha': 'a', 'val': 10, 'num': ['one', 'two']}, 
    {'alpha': 'b', 'val': 22, 'num': ['two']}, 
    {'alpha': 'c', 'val': 1, 'num': ['seven']}, 
    {'alpha': 'a', 'val': 10, 'num': ['three','nine']}, 
    {'alpha': 'b', 'val': 9, 'num': ['two', 'four']}] 

Der Ausgang ich will, ist:

[{'alpha': 'a', 'TotalVal': 20, num: ['one', 'two', 'three', 'nine'], 'numlen': 4}, 
{'alpha': 'b', 'TotalVal': 31, num: ['two', 'four'], 'numlen': 2}, 
{'alpha': 'c', 'val': 1, 'num': ['seven'], 'numlen': 1}] 

Ich habe versucht, die folgenden:

sumVal = collections.defaultdict(float) 
for info in a: 
    sumVal[info['alpha']] += info['val'] 

sumVal = [{'alpha': c, 'TotalVal': sumVal[c]} for c in sumVal] 

numList = collections.defaultdict(list) 
for info in a: 
    numList[info['alpha']].append(info['num']) 
numList = [{'alpha': k, 'num': set(v), 'len': len(set(v))} for k, v in numList.items()] 

def merge_lists(l1, l2, key): 
    merged = {} 
    for item in l1+l2: 
     if item[key] in merged: 
      merged[item[key]].update(item) 
     else: 
      merged[item[key]] = item 
    return [val for (_, val) in merged.items()] 

final = merge_lists(sumVal, numList, 'alpha') 

Ich bekomme nicht die gewünschte Ausgabe für numList. Erhalte den folgenden Fehler.

TypeError: unhashable type: 'list'

Wie kann ich die gewünschte Ausgabe in weniger Schritten erhalten und den Fehler loswerden?

Answer 1

Versuchen Sie diesen Code:

a = [{'alpha':'a','val':10,'num':['one','two']},{'alpha':'b','val':22,'num':['two']},{'alpha':'c','val':1,'num':['seven']},{'alpha':'a','val':10,'num':['three','nine']},{'alpha':'b','val':9,'num':['two','four']}] 

def merge_dicts(x, y): 
    x.update(y) 
    return x 

def r(acc, x): 
    if x['alpha'] in acc: 
     acc[x['alpha']]['TotalVal'] += x['val'] 
     acc[x['alpha']]['num'] |= set(x['num']) 
     acc[x['alpha']]['numlen'] = len(acc[x['alpha']]['num']) 
    else: 
     acc[x['alpha']] = { 
      'TotalVal': x['val'], 
      'num': set(x['num']), 
      'numlen': len(set(x['num'])), 
     } 
    return acc 

result = map(lambda (x, y): merge_dicts({'alpha': x}, y), 
      reduce(r, a, {}).iteritems()) 
print(result) 

Answer 2

Das Problem in dieser Linie ist:

numList[info['alpha']].append(info['num']) 

eine Liste auf einer Liste angehängt, legt die Liste, die Sie in der Liste anhängen Sie Anhängen an .

Ich denke, was Sie wollen, ist zu erweitern.

append vs. extend

Answer 3

#!/usr/bin/env python 

a = [{'alpha':'a','val':10,'num':['one','two', 'one', 'two']},{'alpha':'b','val':22,'num':['two']},{'alpha':'c','val':1,'num':['seven']},{'alpha':'a','val':10,'num':['three','nine']},{'alpha':'b','val':9,'num':['two','four']}] 


def merge_lists(src, key): 
    merged = {} 
    for i in src: 
     _key = i[key] 
     if _key in merged: 
      merged[_key]['TotalVal'] += i['val'] 
      merged[_key]['num'].extend(i['num']) 
      merged[_key]['num'] = list(set(i['num'])) 
      merged[_key]['numlen'] = len(merged[_key]['num']) 
     else: 
      merged[_key] = {'TotalVal': i['val'], 'alpha': i['alpha'], 'num': i['num'], 'numlen': 1} 

    return [val for (_, val) in merged.items()] 


final = merge_lists(a, 'alpha') 

print(final) 

Output: [{ 'alpha': 'a', 'TotalVal': 20 'num' [ 'neun', 'drei'], 'numlen': 2 }, {'alpha': 'c', 'Gesamtwert': 1, 'num': ['sieben'], 'numlen': 1}, {'alpha': 'b', 'TotalVal': 31, ' num ': [' vier‘, 'zwei'], 'numlen': 2}]

Answer 4

Nicht so kurz wie andere Antworten, aber einfach in der Implementierung

a = [{'alpha':'a','val':10,'num':['one','two']}, 
    {'alpha':'b','val':22,'num':['two']}, 
    {'alpha':'c','val':1,'num':['seven']}, 
    {'alpha':'a','val':10,'num':['three','nine']}, 
    {'alpha':'b','val':9,'num':['two','four']}] 

new_list = [] 

# Loop through entries 
for entry in a: 
    # Store first entries 
    if entry['alpha'] not in [i['alpha'] for i in new_list]: 
     new_dict = {'alpha': entry['alpha'], 
        'TotalVal': entry['val'], 
        'num': entry['num'], 
        'numlen': len(entry['num'])} 
     new_list.append(new_dict) 
     continue 

    # Add in additional entries 
    for i, n in enumerate(new_list): 
     if n['alpha'] == entry['alpha']: 
      entry_vals = entry.values() 
      new_list[i]['TotalVal'] = new_list[i]['TotalVal'] + entry['val'] 
      new_list[i]['num'] = new_list[i]['num'] + entry['num'] 
      new_list[i]['numlen'] = len(new_list[i]['num']) 

# filter final data 
for i, n in enumerate(new_list): 
    # Remove duplicate entries in num 
    for entry in n['num']: 
     if n['num'].count(entry) > 1: 
      new_list[i]['num'].remove(entry) 

    # Update numlen 
    new_list[i]['numlen'] = len(new_list[i]['num']) 

print new_list 

Answer 5

Hier ist die einfachste Lösung, die ich kam mit:

a = [{'alpha':'a','val':10,'num':['one','two']}, 
    {'alpha':'b','val':22,'num':['two']}, 
    {'alpha':'c','val':1,'num':['seven']}, 
    {'alpha':'a','val':10,'num':['three','nine']}, 
    {'alpha':'b','val':9,'num':['two','four']}] 

a2 = [] 
alphas = set(d['alpha'] for d in a) 
for alpha in alphas: 
    TotalVal, num, numlen = 0, set(), 0 
    for d in a: 
     if d['alpha'] == alpha: 
      TotalVal += d['val'] 
      num = num | set(d['num']) 
      numlen += 1 
    new_dict = {'alpha': alpha, 'num': list(num), 'numlen': numlen} 
    if numlen > 1: 
     new_dict['TotalVal'] = TotalVal 
    else: 
     new_dict['val'] = TotalVal 
    a2.append(new_dict) 

Demo:

>>> for d in a2: print(d) 
{'alpha': 'a', 'num': ['three', 'nine', 'two', 'one'], 'numlen': 2, 'TotalVal': 20} 
{'alpha': 'c', 'num': ['seven'], 'numlen': 1, 'val': 1} 
{'alpha': 'b', 'num': ['four', 'two'], 'numlen': 2, 'TotalVal': 31}