python - Python - 从外部文本文件创建字典

Question

所以我的文件看起来像这样：

0 1
0 2
0 34
0 67
1 98
1 67
1 87
2 23
2 45
2 98
...

等等。我的问题是，我怎样才能从这个文本文件中制作一个看起来像这样的字典：

dict = {'0':['1', '2', '34', '67']
        '1':['98', '67', '87']
        '2':['23', '45', '98']
        '3':['x','x','x']}

Answer 1

假设文件被称为test.txt：

from collections import defaultdict
import csv


data = defaultdict(list)
with open("test.txt", "r") as f:
    reader = csv.reader(f, delimiter=" ")
    for row in reader:
        data[row[0]].append(row[1])

那么data值将是：

{
 '0': ['1', '2', '34', '67'], 
 '1': ['98', '67', '87'], 
 '2': ['23', '45', '98'],
 ...
}

Answer 2

一个非常有趣且优雅的解决方案：

>>> from collections import defaultdict
>>> d = defaultdict(list)
>>> with open(external_file) as f:
    map(lambda x: d[x[0]].append(x[1]), map(str.split, f))
>>> d
defaultdict(<type 'list'>, {'1': ['98', '67', '87'], '0': ['1', '2', '34', '67'], '2': ['23', '45', '98']})

Answer 3

from collections import defaultdict
res = defaultdict(list)
with open(file) as f:
    for line in f:
        temp = line.split()
        res[temp[0]].append(temp[1])