[英]How can I add key values into a dictionary from reading in each line of a .txt file and update values?
[英]How to create Python dictionary with multiple 'lists' for each key by reading from .txt file?
我有一個大文本文件,看起來像:
1 27 21 22
1 151 24 26
1 48 24 31
2 14 6 8
2 98 13 16
.
.
.
我想用它創建一個字典。 每個列表的第一個數字應該是字典中的鍵,應該采用以下格式:
{1: [(27,21,22),(151,24,26),(48,24,31)],
2: [(14,6,8),(98,13,16)]}
我有以下代碼(總點數是文本文件第一列中的最大數字(即字典中的最大鍵)):
from collections import defaultdict
info = defaultdict(list)
filetxt = 'file.txt'
i = 1
with open(filetxt, 'r') as file:
for i in range(1, num_cities + 1):
info[i] = 0
for line in file:
splitLine = line.split()
if info[int(splitLine[0])] == 0:
info[int(splitLine[0])] = ([",".join(splitLine[1:])])
else:
info[int(splitLine[0])].append((",".join(splitLine[1:])))
哪個輸出
{1: ['27,21,22','151,24,26','48,24,31'],
2: ['14,6,8','98,13,16']}
我想要這個字典的原因是因為我想在給定鍵的字典的每個“內部列表”中運行for循環:
for first, second, third, in dictionary:
....
我不能用我當前的代碼執行此操作,因為字典的格式略有不同(它在上面的for循環中需要3個值,但是接收的值超過3個),但它可以使用第一個字典格式。
任何人都可以建議解決這個問題嗎?
result = {}
with open(filetxt, 'r') as f:
for line in f:
# split the read line based on whitespace
idx, c1, c2, c3 = line.split()
# setdefault will set default value, if the key doesn't exist and
# return the value corresponding to the key. In this case, it returns a list and
# you append all the three values as a tuple to it
result.setdefault(idx, []).append((int(c1), int(c2), int(c3)))
編輯:由於您希望鍵也是一個整數,您可以將int
函數map
到拆分值,如下所示
idx, c1, c2, c3 = map(int, line.split())
result.setdefault(idx, []).append((c1, c2, c3))
您正在將值轉換回逗號分隔的字符串,這些字符串不能用於數據中for first, second, third in data
- 所以只需將它們保留為列表splitLine[1:]
(或轉換為tuple
)。
您不需要使用defaultdict
初始化for
循環。 您也不需要使用defaultdict
進行條件檢查。
你的代碼沒有多余的代碼:
with open(filetxt, 'r') as file:
for line in file:
splitLine = line.split()
info[int(splitLine[0])].append(splitLine[1:])
一個細微的差別是如果你想在int
上運行我會在前面進行轉換:
with open(filetxt, 'r') as file:
for line in file:
splitLine = list(map(int, line.split())) # list wrapper for Py3
info[splitLine[0]].append(splitLine[1:])
實際上在Py3中,我會這樣做:
idx, *cs = map(int, line.split())
info[idx].append(cs)
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