Converting a csv to dict with multiple values-CodePudding

I have a csv that when loaded looks like this.

chicken, meat
veal, meat
rice, carbs
potato, carbs
carrot, veggies
mushroom, veggies
apples, fruits

I want to create a dictionary from it, so I'm using the code:

food = pd.read_csv('foods.csv',  header=None, index_col=1, squeeze=False).to_dict()

When i print the dictionary only one item is showing for each key. Instead I would like all to show like this.

{'carbs':['potato','rice'],
'meat':['chicken','veal'],
'veggies':['mushroom','carrot'],
'fruits':['apples']}

CodePudding user response：

You can skip Pandas and deal with the file directly. Since you actually have a two character delimiter ', ' it is easier to skip csv too:

di={}
with open('/tmp/fruit.csv') as f:
    for x,y in (line.rstrip().split(', ') for line in f):
        di.setdefault(y, []).append(x)

>>> di
{'meat': ['chicken', 'veal'], 'carbs': ['rice', 'potato'], 'veggies': ['carrot', 'mushroom'], 'fruits': ['apples']}

Or use pandas:

df=pd.read_csv('/tmp/fruit.csv',  header=None, sep=', ', engine='python').groupby([1])[0].agg(list).to_dict()

>>> df
{'carbs': ['rice', 'potato'], 'fruits': ['apples'], 'meat': ['chicken', 'veal'], 'veggies': ['carrot', 'mushroom']}

CodePudding user response：

If you don't need Pandas, this can be done easily enough using Python's CSV reader.

import csv
from collections import defaultdict


category_food_map = defaultdict(list)

with open('foods.csv', newline='') as f:
    reader = csv.reader(f)

    for row in reader:
        food, category = row
        category = category.strip()

        category_food_map[category].append(food)


for category, food in category_food_map.items():
    print(f'{category}: {food}')

and I get:

meat: ['chicken', 'veal']
carbs: ['rice', 'potato']
veggies: ['carrot', 'mushroom']
fruits: ['apples']