将CSV转换为JSON会忽略最后一行吗？

Question

尝试在添加根节点的同时，尽可能简单地将CSV文件转换为JSON文件。出于某种原因，JSON文件至少省略了CSV文件末尾的最后一行（在某些情况下多达4行）。这是怎么回事？

示例CSV

name, id, tag
John, 12345, father
Mary, 33456, sister
Beth, 56789, daughter

期望JSON

{"node": "", "children": [
{"name": "John", "id": 12345, "tag": "father"},
{"name": "Mary", "id": 33456, "tag": "sister"},
{"name": "Beth", "id": 56789, "tag": "daughter"}
]}

我得到的是：

 {"node": "", "children": [
    {"name": "John", "id": 12345, "tag": "father"},
    {"name": "Mary", "id": 33456, "tag": "sister"},
    ]}

我的代码：

csvfile = open('file.csv', 'r')
jsonfile = open('file.json', 'w')

reader = csv.DictReader(csvfile)
jsonfile.write('{"node": "", "children": [')
for row in reader:
    json.dump(row, jsonfile)
    #jsonfile.write(',\n')
jsonfile.write('] }')

另外，我知道我在JSON文件的最后一行添加了一个逗号——我也想知道除了最后一行之外如何添加逗号，但这并不重要。

Answer 1

您不需要手动构造JSON字符串。创建一个Python数据结构，然后通过json.dump（）将其转储到json文件中：

import json

reader = csv.DictReader(csvfile)
data = {"node": "", "children": list(reader)}

with open('file.json', 'w') as jsonfile:    
    json.dump(data, jsonfile)