python json到csv转换脚本？

Question

让我先说一下，我是python新手。我编写了一个脚本，将.json文件转换为csv格式。我设法编写了一个脚本来完成这项工作，但是我认为如果json文件的格式发生变化，我的脚本将无法工作。我的脚本假设json文件在任何时候都是相同的格式。在

<json file example>
 {
"Order":
    {
        "order_id":"8251662",
        "order_date":"2012-08-20 13:17:37",
        "order_date_shipped":"0000-00-00 00:00:00",
        "order_status":"fraudreview",
        "order_ship_firstname":"pam",
        "order_ship_lastname":"Gregorio",
        "order_ship_address1":"1533 E. Dexter St",
        "order_ship_address2":"",
        "order_ship_city":"Covina",
        "order_ship_state":"CA",
        "order_ship_zip":"91746",
        "order_ship_country":"US United States",
        "order_ship_phone":"6268936923",
        "order_ship_email":"pgregorio@brighton.com",
        "order_bill_firstname":"pam",
        "order_bill_lastname":"Gregorio",
        "order_bill_address1":"1533 E. Dexter St",
        "order_bill_address2":"",
        "order_bill_city":"Covina",
        "order_bill_state":"CA",
        "order_bill_zip":"91746",
        "order_bill_country":"US United States",
        "order_bill_phone":"6268936923",
        "order_bill_email":"pgregorio@brighton.com",
        "order_gift_message":"",
        "order_giftwrap":"0",
        "order_gift_charge":"0",
        "order_shipping":"Standard (Within 5-10 Business Days)",
        "order_tax_charge":"62.83",
        "order_tax_shipping":"0",
        "order_tax_rate":"0.0875",
        "order_shipping_charge":"7.5",
        "order_total":"788.33",
        "order_item_count":"12",
        "order_tracking":"",
        "order_carrier":"1"
    },

"Items":
    [
    {
        "item_id":"25379",
        "item_date_shipped":"",
        "item_code":"17345-J3553-J35532",
        "item_quantity":"2","item_taxable":"YES",
        "item_unit_price":"32","item_shipping":"0.67",
        "item_addcharge_price":"0",
        "item_description":" ABC Slide Bracelet: : Size: OS: Silver Sku: J35532",
        "item_quantity_returned":"0",
        "item_quantity_shipped":"0",
        "item_quantity_canceled":"0",
        "item_status":"pending",
        "item_product_id":"17345",
        "item_product_kit_id":"0",
        "item_product_sku":"J35532",
        "item_product_barcode":"881934310775",
        "item_tracking":"",
        "item_carrier":"0",
        "item_source_orderid":""
    },
    {
        "item_id":"25382",
        "item_date_shipped":"",
        "item_code":"17608-J3809-J3809C",
        "item_quantity":"1",
        "item_taxable":"YES",
        "item_unit_price":"22",
        "item_shipping":"0.23",
        "item_addcharge_price":"0",
        "item_description":" \"ABC Starter Bracelet 7 1\/4\"\"\": : Size: OS: Silver Sku: J3809C",
        "item_quantity_returned":"0",
        "item_quantity_shipped":"0",
        "item_quantity_canceled":"0",
        "item_status":"pending",
        "item_product_id":"17608",
        "item_product_kit_id":"0",
        "item_product_sku":"J3809C",
        "item_product_barcode":"881934594175",
        "item_tracking":"",
        "item_carrier":"0",
        "item_source_orderid":""
    },
    {
        "item_id":"25385",
        "item_date_shipped":"",
        "item_code":"17687-J9200-J92000",
        "item_quantity":"2",
        "item_taxable":"YES",
        "item_unit_price":"12",
        "item_shipping":"0.25",
        "item_addcharge_price":"0",
        "item_description":" ABC Cathedral Bead: : Size: OS: Silver Sku: J92000",
        "item_quantity_returned":"0",
        "item_quantity_shipped":"0",
        "item_quantity_canceled":"0",
        "item_status":"pending",
        "item_product_id":"17687",
        "item_product_kit_id":"0",
        "item_product_sku":"J92000",
        "item_product_barcode":"881934602832",
        "item_tracking":"",
        "item_carrier":"0",
        "item_source_orderid":""
    },
    {
        "item_id":"25388",
        "item_date_shipped":"",
        "item_code":"17766-J9240-J92402",
        "item_quantity":"2",
        "item_taxable":"YES",
        "item_unit_price":"22",
        "item_shipping":"0.46",
        "item_addcharge_price":"0",
        "item_description":" ABC Ice Diva Bead: : Size: OS: Silver Sku: J92402",
        "item_quantity_returned":"0",
        "item_quantity_shipped":"0",
        "item_quantity_canceled":"0",
        "item_status":"pending",
        "item_product_id":"17766",
        "item_product_kit_id":"0",
        "item_product_sku":"J92402",
        "item_product_barcode":"881934655838",
        "item_tracking":"",
        "item_carrier":"0",
        "item_source_orderid":""
    },
    ],

"FraudReasons":
    [
    {
        "order_id":"11957",
        "fraud_reason":"order total exceeds max amount"
    },
    {
        "order_id":"11957",
        "fraud_reason":"order exceeds max item count"
    }
]
}

我的脚本目前可以很好地处理这个json文件，但是如果只有一个条目或一个fraudreason，它就不能工作了。这是我的脚本代码。在

^{pr2}$

我也不知道如何不使用标签，我希望有人能帮助我

提前谢谢。在

Answer 1

您应该向json生成的对象（data）询问字段的名称。要保留输入顺序，请告诉json使用collections.OrderedDict而不是普通的dict（需要python2.7）：

import json
from collections import OrderedDict as ordereddict

data = json.loads(open('mydata.json', object_pairs_hook=ordereddict)
orders = data['Order']
print orders.keys()  # Will print the keys in the order they were read

然后可以使用orders.keys()代替硬编码列表，可以与writerow一起使用，也可以使用（更简单的）与csv.DictWriter一起使用。在

注意，这使用默认的json，而不是simplejson，并且需要使用python2.7作为ordered_pairs_hook参数和OrderedDict类型。在

编辑：是的，我从评论中看到你一直坚持2.4。您可以从PyPi下载一个ordereddict，并且可以扩展^{}类，并用cls参数传递它（请参见here），而不是{}，但这更难看，也需要更多的工作。。。在

Answer 2

您可能需要使用csv.DictWriter：

    # It's considered best to stash the main logic of your script
    # in a main() function like this.
    def main(filename, options):
        with open(filename) as fi:
            data = json.load(fi)

        csv_file = '/tmp/' + str(options.orderId) + '.csv'
        order = data['Order']
        items = data['Items']
        frauds = data['FraudReasons']

        # Here's one way to keep this maintainable if the JSON
        # format changes, and you don't care too much about the
        # order of the fields...
        orders_fields = sorted(orders.keys())
        item_fields = sorted(items[0].keys()) if items else ()
        fraud_fields = sorted(fraud[0].keys()) if fraud else ()

        csv_options = dict(lineterminator=',')

        with open(csv_file, 'w') as fo:
            o = csv.DictWriter(fo, order_fields, **csv_options)
            o.writeheader()
            o.writerow(orders)

            fo.write('\n')  # Optional, if you want to keep them separated.
            o = csv.DictWriter(fo, item_fields, **csv_options)
            o.writeheader()
            o.writerows(items)

            fo.write('\n')  # Optional, if you want to keep them separated.
            o = csv.DictWriter(fo, fraud_fields, **csv_options)
            o.writeheader()
            o.writerows(frauds)

    # If this script is run from the command line, just run
    # main(). Here's the place to use `optparse`.
    if __name__ == '__main__':
        main(...) # You'll need to fill in the main() arguments...

如果需要指定字段的顺序，请将它们分配给如下所示的元组：

^{pr2}$