For the following data, how can i create a dictionary with id as the key and value of array of tuple [(x, y)]
id x y
0 a 1 2
1 a 2 3
2 b 3 4
The expected dictionary is
{a: [(1,2), (2,3)], b:[(3,4)]}
1
-
Possibly a duplicate of stackoverflow.com/questions/26367812/…Ray Toal– Ray Toal2016-02-01 03:04:14 +00:00Commented Feb 1, 2016 at 3:04
Add a comment
|
2 Answers
When iterating over the table (however you are doing it) check if the id is already in the dict and append to the existing value or add the new key:
data = {}
for id,x,y in SOURCE:
if id in data:
data[id].append((x,y))
else:
data[id] = [(x,y)]
answered Feb 1, 2016 at 2:57
Tadhg McDonald-Jensen
21.6k5 gold badges40 silver badges69 bronze badges
Comments
The solution offered by @tadhg-mcdonald-jensen seems a perfect opportunity to take advantage of a defaultdict:
from collections import defaultdict
data = defaultdict(list)
with open(SOURCE_FILE_NAME) as source:
for line in source:
id, x, y = line.rstrip().split()
data[id].append((x, y))
This avoids the decision to set or append -- simply append and let the defaultdict do the right thing for you.
