将JSON URL转换为R数据框 [英] Convert JSON URL to R Data Frame

问题描述

我在将JSON文件(从API)转换为R中的数据帧时遇到麻烦.URL

I'm having trouble converting a JSON file (from an API) to a data frame in R. An example is the URL http://api.fantasy.nfl.com/v1/players/stats?statType=seasonStats&season=2010&week=1&format=json

我尝试了来自S/O的一些不同建议，包括 将json数据转换为R中的数据框和各种博客文章例如 http://zevross.com/blog/2015/02/12/using-r-to-download-and-parse-json-an-example-using-data -from-open-data-portal/

I've tried a few different suggestions from S/O, including convert json data to data frame in R and various blog posts such as http://zevross.com/blog/2015/02/12/using-r-to-download-and-parse-json-an-example-using-data-from-an-open-data-portal/

我最近一直在使用下面的代码，它为我提供了一个大矩阵，其中包含4个行"和一堆变量"(V1，V2等).我假设此JSON文件的格式与普通"文件的格式不同.

The closest I've been is using the code below which gives me a large matrix with 4 "rows" and a bunch of "varables" (V1, V2, etc.). I'm assuming that this JSON file is in a different format than "normal" ones.

library(RJSONIO)

raw_data <- getURL("http://api.fantasy.nfl.com/v1/players/stats?statType=seasonStats&season=2010&week=1&format=json")

data <- fromJSON(raw_data)

final_data <- do.call(rbind, data)

我对如何使其工作完全不可知，因此欢迎任何R包/过程.提前致谢.

I'm pretty agnostic as to how to get it to work so any R packages/process are welcome. Thanks in advance.

推荐答案

此JSON没有什么异常"之处，它不是简单地适合数据框架的矩形结构. JSON可以表示更丰富的数据结构.

There's nothing "abnormal" about this JSON, its just not a rectangular structure that fits trivially into a data frame. JSON can represent much richer data structures.

例如(使用rjson包，您没有说过使用的内容):

For example (using the rjson package, you've not said what you've used):

> data = rjson::fromJSON(file="http://api.fantasy.nfl.com/v1/players/stats?statType=seasonStats&season=2010&week=1&format=json")
> length(data[[4]][[10]]$stats)
[1] 14
> length(data[[4]][[1]]$stats)
[1] 21

(data[[1 to 3]]看起来像标题)

data[[4]]的第10个元素的统计"有14个元素，第一个元素的统计"有21个元素.如何适应矩形数据框? R已将其存储在列表中，因为这是R存储不规则数据结构的最佳方法.

the "stats" of the 10th element of data[[4]] has 14 elements, the "stats" of the first has 21. How is that going to fit into a rectangular data frame? R has stored it in a list because that's R's best way of storing irregular data structures.

除非您可以定义将不规则数据映射到矩形数据框中的方法，否则不能将其存储在数据框中.您了解数据的结构吗?这是必不可少的.

Unless you can define a way of mapping the irregular data into a rectangular data frame, you can't store it in a data frame. Do you understand the structure of the data? That's essential.

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