使用 Python 将 CSV 转换为 JSON（以特定格式）

Question

我想使用 python 2.7 将 csv 文件转换为 json 文件。下面是我尝试过的python代码，但它没有给我预期的结果。另外，我想知道是否有比我的简化版本。任何帮助表示赞赏。

这是我的 csv 文件 (SampleCsvFile.csv)：

zipcode,date,state,val1,val2,val3,val4,val5
95110,2015-05-01,CA,50,30.00,5.00,3.00,3
95110,2015-06-01,CA,67,31.00,5.00,3.00,4
95110,2015-07-01,CA,97,32.00,5.00,3.00,6

这是预期的 json 文件（ExpectedJsonFile.json）：

{
        "zipcode": "95110", 
        "state": "CA", 
        "subset": [
            {
                "date": "2015-05-01",
                "val1": "50", 
                "val2": "30.00", 
                "val3": "5.00", 
                "val4": "3.00", 
                "val5": "3"
            }, 
            {
                "date": "2015-06-01", 
                "val1": "67", 
                "val2": "31.00", 
                "val3": "5.00", 
                "val4": "3.00", 
                "val5": "4"
            }, 
            {
                "date": "2015-07-01", 
                "val1": "97", 
                "val2": "32.00", 
                "val3": "5.00", 
                "val4": "3.00", 
                "val5": "6"
            }
        ]

}

这是我试过的python代码：

import pandas as pd
from itertools import groupby 
import json    

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

names = df.columns.values.tolist()
data = df.values

master_list2 = [ (d["zipcode"], d["state"], d) for d in [dict(zip(names, d)) for d in data] ]
intermediate2 = [(k, [x[2] for x in list(v)]) for k,v in groupby(master_list2, lambda t: (t[0],t[1]) )]
nested_json2 = [dict(zip(names,(k[0][0], k[0][1], k[1]))) for k in [(i[0], i[1]) for i in intermediate2]]

#print json.dumps(nested_json2, indent=4)
with open('ExpectedJsonFile.json', 'w') as outfile:
     outfile.write(json.dumps(nested_json2, indent=4))

Answer 1

由于您已经在使用 pandas，我试图从数据框方法中获得尽可能多的里程。我最终也与您的实施相去甚远。不过，我认为这里的关键是不要试图对你的列表和/或字典理解变得太聪明。您很容易混淆自己和阅读您代码的每个人。

import pandas as pd
from itertools import groupby 
from collections import OrderedDict
import json    

df = pd.read_csv('SampleCsvFile.csv', dtype={
            "zipcode" : str,
            "date" : str,
            "state" : str,
            "val1" : str,
            "val2" : str,
            "val3" : str,
            "val4" : str,
            "val5" : str
        })

results = []

for (zipcode, state), bag in df.groupby(["zipcode", "state"]):
    contents_df = bag.drop(["zipcode", "state"], axis=1)
    subset = [OrderedDict(row) for i,row in contents_df.iterrows()]
    results.append(OrderedDict([("zipcode", zipcode),
                                ("state", state),
                                ("subset", subset)]))

print json.dumps(results[0], indent=4)
#with open('ExpectedJsonFile.json', 'w') as outfile:
#    outfile.write(json.dumps(results[0], indent=4))

将所有 json 数据类型写入字符串并保留其原始格式的最简单方法是强制 read_csv 将它们解析为字符串。但是，如果您需要在写出 json 之前对值进行任何数值操作，则必须允许 read_csv 对它们进行数值解析并在转换为 json 之前将它们强制转换为正确的字符串格式。