csv到嵌套的JSON？ [关闭]答案

【问题标题】：csv to nested JSON? [closed]csv到嵌套的JSON？ [关闭]
【发布时间】：2016-06-28 10:23:44
【问题描述】：

我正在尝试将平面结构的 CSV 转换为嵌套的 JSON 结构。 CSV 是从 SQL 生成的，它为每个主 ID 创建多行。 CSV 的结构如下：

PrimaryId,FirstName,LastName,City,CarName,DogName
100,John,Smith,NewYork,Toyota,Spike
100,John,Smith,NewYork,BMW,Spike
100,John,Smith,NewYork,Toyota,Rusty
100,John,Smith,NewYork,BMW,Rusty
101,Ben,Swan,Sydney,Volkswagen,Buddy
101,Ben,Swan,Sydney,Ford,Buddy
101,Ben,Swan,Sydney,Audi,Buddy
101,Ben,Swan,Sydney,Volkswagen,Max
101,Ben,Swan,Sydney,Ford,Max
101,Ben,Swan,Sydney,Audi,Max
102,Julia,Brown,London,Mini,Lucy

所需的 JSON 输出是：

{
    "data": [
        {
            "City": "NewYork", 
            "FirstName": "John", 
            "PrimaryId": 100, 
            "LastName": "Smith", 
            "CarName": [
                "Toyota", 
                "BMW"
            ], 
            "DogName": [
                "Spike", 
                "Rusty"
            ]
        }, 
        {
            "City": "Sydney", 
            "FirstName": "Ben", 
            "PrimaryId": 101, 
            "LastName": "Swan", 
            "CarName": [
                "Volkswagen", 
                "Ford", 
                "Audi"
            ], 
            "DogName": [
                "Buddy", 
                "Max"
            ]
        }, 
        {
            "City": "London", 
            "FirstName": "Julia", 
            "PrimaryId": 102, 
            "LastName": "Brown", 
            "CarName": [
                "Mini"
            ], 
            "DogName": [
                "Lucy"
            ]
        }
    ]
}

this post 和 this one 都有帮助，但我还没有创建正确的结构。

【问题讨论】：

请在此处发布您的代码，即您尝试了什么。此外，您的 csv 似乎有多余的空格，而且您的 json 也绝对不是 json。

标签： python json csv

【解决方案1】：

您的数据，转换为有效的 csv 保存在data.csv：

PrimaryId,FirstName,LastName,City,CarName,DogName
100,John,Smith,NewYork,Toyota,Spike
100,John,Smith,NewYork,BMW,Spike
100,John,Smith,NewYork,Toyota,Rusty
100,John,Smith,NewYork,BMW,Rusty
101,Ben,Swan,Sydney,Volkswagen,Buddy
101,Ben,Swan,Sydney,Ford,Buddy
101,Ben,Swan,Sydney,Audi,Buddy
101,Ben,Swan,Sydney,Volkswagen,Max
101,Ben,Swan,Sydney,Ford,Max
101,Ben,Swan,Sydney,Audi,Max
102,Julia,Brown,London,Mini,Lucy

使用 pandas 完成繁重的工作，并假设这个有效的 csv 文件，这是做你想做的事情的一种方式：

import json
import pandas as pd

df = pd.read_csv('data.csv')

def get_nested_rec(key, grp):
    rec = {}
    rec['PrimaryId'] = key[0]
    rec['FirstName'] = key[1]
    rec['LastName'] = key[2]
    rec['City'] = key[3]

    for field in ['CarName','DogName']:
        rec[field] = list(grp[field].unique())

    return rec

records = []
for key, grp in df.groupby(['PrimaryId','FirstName','LastName','City']):
    rec = get_nested_rec(key, grp)
    records.append(rec)

records = dict(data = records)

print(json.dumps(records, indent=4))

结果：

{
    "data": [
        {
            "City": "NewYork", 
            "FirstName": "John", 
            "PrimaryId": 100, 
            "LastName": "Smith", 
            "CarName": [
                "Toyota", 
                "BMW"
            ], 
            "DogName": [
                "Spike", 
                "Rusty"
            ]
        }, 
        {
            "City": "Sydney", 
            "FirstName": "Ben", 
            "PrimaryId": 101, 
            "LastName": "Swan", 
            "CarName": [
                "Volkswagen", 
                "Ford", 
                "Audi"
            ], 
            "DogName": [
                "Buddy", 
                "Max"
            ]
        }, 
        {
            "City": "London", 
            "FirstName": "Julia", 
            "PrimaryId": 102, 
            "LastName": "Brown", 
            "CarName": [
                "Mini"
            ], 
            "DogName": [
                "Lucy"
            ]
        }
    ]
}

【讨论】：

【解决方案2】：

这是使用csv.DictReader 的一般方法。

从加载数据开始：

import csv
import itertools
with open('stuff.csv', 'rb') as csvfile:
    all_ = list(csv.DictReader(csvfile))

现在，您可以使用itertools.groupby 对每个组进行分组和处理。例如

d = []
for k, g in itertools.groupby(
        all_, 
        key=lambda r: (r['PrimaryId'], r[' LastName'])):
    d.append({
        'PrimaryId': k[0],
        'LastName': k[1],
        'CarName': [e[' CarName'] for e in g]
        })

将按主 ID 和姓氏分组，并列出汽车。

一旦你有了这样的东西，你就可以使用json.dumps()。

【讨论】：