如何从 JSON 文件中读取数据

Question

I have a JSON file with the following data:

{
    "id": 1008, 
    "description": "Cheese, caraway", 
    "tags": [ ], 
    "manufacturer": "", 
    "group": "Dairy and Egg Products", 
    "portions": [
        {
            "amount": 1, 
            "unit": "oz", 
            "grams": 28.35
        }
    ], 
    "nutrients": [
        {
            "value": 25.18, 
            "units": "g", 
            "description": "Protein", 
            "group": "Composition"
        }, 
        {
            "value": 29.2, 
            "units": "g", 
            "description": "Total lipid (fat)", 
            "group": "Composition"
        }, 
        {
            "value": 3.06, 
            "units": "g", 
            "description": "Carbohydrate, by difference", 
            "group": "Composition"
        }, 
        {
            "value": 3.28, 
            "units": "g", 
            "description": "Ash", 
            "group": "Other"
        }
    ]
}

and I use the following codes to try to read from it:

import json
path = 'C:\\Users\\IBM_ADMIN\\Desktop\\ml-1m\\food_nutrients_database - 副本.json'
data = open(path).read()
records = json.loads(data)

but I get the following error:

records = json.loads(data)
ValueError: Expecting value: line 1 column 1 (char 0)

What's the problem here? I noticed the result returned from "data" begins with "'锘縶". Could this be the reason? If so, how can I resolve it?

Answer 1

Don't do that. Just pass the data from the file as a whole.

data = open(path).read()
records = json.loads(data)

You can make it even shorter by using load() , which takes the file object itself:

records = json.load(open(path))

Answer 2

What you are doing wrong is that you are reading each line from the JSON file and passing it to json.load() . Instead, all you need to do is open the file once, read the contents, and then pass it to the json.load() method. That will work.

file_data = open(path).read()
json_data = json.loads(file_data)

Also, the posted JSON format is incorrect, so make sure your JSON format is correct.

Answer 3

You're reading the lines individually from strings. Try this instead:

import json

with open(path, 'r') as infile:
    data = json.load(infile)

json.loads is to load a string to a json object so be sure not to confuse it with json.load