Question

我在将JSON转换为可用数据框时遇到问题。当源JSON具有多个级别时，就会出现问题，并且使用fromJSON的结果最终是较大数据帧中的数据帧列。该数据帧列在其内部也具有列表和数据帧。我想展平整个文件以检索一个数据框并从中选择必要的列。

我可以使用Shopify API为例：

"line_items": [
  {
    "fulfillable_quantity": 1,
    "fulfillment_service": "amazon",
    "fulfillment_status": "fulfilled",
    "grams": 500,
    "id": 669751112,
    "price": "199.99",
    "product_id": 7513594,
    "quantity": 1,
    "requires_shipping": true,
    "sku": "IPOD-342-N",
    "title": "IPod Nano",
    "variant_id": 4264112,
    "variant_title": "Pink",
    "vendor": "Apple",
    "name": "IPod Nano - Pink",
    "gift_card": false,
    "price_set": {
      "shop_money": {
        "amount": "199.99",
        "currency_code": "USD"
      },
      "presentment_money": {
        "amount": "173.30",
        "currency_code": "EUR"
      }
    },
    "properties": [
      {
        "name": "custom engraving",
        "value": "Happy Birthday Mom!"
      }
    ],
    "taxable": true,
    "tax_lines": [
      {
        "title": "HST",
        "price": "25.81",
        "price_set": {
          "shop_money": {
            "amount": "25.81",
            "currency_code": "USD"
          },
          "presentment_money": {
            "amount": "20.15",
            "currency_code": "EUR"
          }
        },
        "rate": 0.13
      }
    ],
    "total_discount": "5.00",
    "total_discount_set": {
      "shop_money": {
        "amount": "5.00",
        "currency_code": "USD"
      },
      "presentment_money": {
        "amount": "4.30",
        "currency_code": "EUR"
      }
    },
    "discount_allocations": [
      {
        "amount": "5.00",
        "discount_application_index": 2,
        "amount_set": {
          "shop_money": {
            "amount": "5.00",
            "currency_code": "USD"
          },
          "presentment_money": {
            "amount": "3.96",
            "currency_code": "EUR"
          }
        }
      }
    ]
  }
]

如果我使用以下代码检索订单项：

Orders <- fromJSON(paste0("https:key:password//@random-shop.myshopify.com/admin/orders.json?status=any&created_at_max=",Sys.Date()-2,"T23:59:59-05:00&limit=250&created_at_min=",Sys.Date()-2,"T00:00:00-05:00&fields=created_at,id,name,total-price,number,line_items"),flatten = T)
Orders <- Orders$orders%>%
  flatten()
str(Orders)

订单项将显示为不同长度的数据框的列表。在那些数据框中，字段的范围可以从单个列表到数据框。

不幸的是，这是一个很难完全复制的问题。

有没有办法获取数据帧列表并使每个变量成为其自己的列？

Answer 1

使用您上面提供的JSON作为名为test.JSON的文件

导入以获取列表：

library(jsonlite)
orders <- fromJSON("~/Desktop/test.JSON", simplifyVector = F)

# Convert to a dataframe using purrr
library(purrr)
orders2 <- orders %>% 
    map(unlist) %>% 
    map_df(bind_rows)

结果：

# A tibble: 1 x 41
  fulfillable_qua… fulfillment_ser… fulfillment_sta… grams id    price product_id quantity
  <chr>            <chr>            <chr>            <chr> <chr> <chr> <chr>      <chr>   
1 1                amazon           fulfilled        500   6697… 199.… 7513594    1

希望这是您需要的-一个数据框，其中每一列都是列表中的一项。

当一列是数据帧列表时，使用fromJSON转换为一个数据帧吗？

1 个答案: