JSON文件以人類(lèi)可讀格式將數(shù)據(jù)存儲(chǔ)為文本。 Json代表JavaScript Object Notation。 R可以使用rjson包讀取JSON文件。
安裝rjson包
在R語(yǔ)言控制臺(tái)中，您可以發(fā)出以下命令來(lái)安裝rjson包。
install.packages("rjson")
輸入數(shù)據(jù)
通過(guò)將以下數(shù)據(jù)復(fù)制到文本編輯器（如記事本）中來(lái)創(chuàng)建JSON文件。 使用.json擴(kuò)展名保存文件，并將文件類(lèi)型選擇為所有文件（.）。
{
"ID":["1","2","3","4","5","6","7","8" ],
"Name":["Rick","Dan","Michelle","Ryan","Gary","Nina","Simon","Guru" ],
"Salary":["623.3","515.2","611","729","843.25","578","632.8","722.5" ],
"StartDate":[ "1/1/2012","9/23/2013","11/15/2014","5/11/2014","3/27/2015","5/21/2013",
"7/30/2013","6/17/2014"],
"Dept":[ "IT","Operations","IT","HR","Finance","IT","Operations","Finance"]
}
讀取JSON文件
JSON文件由R使用來(lái)自JSON()的函數(shù)讀取。 它作為列表存儲(chǔ)在R中。
Load the package required to read JSON files.
library("rjson")
Give the input file name to the function.
result <- fromJSON(file = "input.json")
Print the result.
print(result)
當(dāng)我們執(zhí)行上面的代碼，它產(chǎn)生以下結(jié)果 -
$ID
[1] "1" "2" "3" "4" "5" "6" "7" "8"
$Name
[1] "Rick" "Dan" "Michelle" "Ryan" "Gary" "Nina" "Simon" "Guru"
$Salary
[1] "623.3" "515.2" "611" "729" "843.25" "578" "632.8" "722.5"
$StartDate
[1] "1/1/2012" "9/23/2013" "11/15/2014" "5/11/2014" "3/27/2015" "5/21/2013"
"7/30/2013" "6/17/2014"
$Dept
[1] "IT" "Operations" "IT" "HR" "Finance" "IT"
"Operations" "Finance"
將JSON轉(zhuǎn)換為數(shù)據(jù)幀
我們可以使用as.data.frame()函數(shù)將上面提取的數(shù)據(jù)轉(zhuǎn)換為R語(yǔ)言數(shù)據(jù)幀以進(jìn)行進(jìn)一步分析。
Load the package required to read JSON files.
library("rjson")
Give the input file name to the function.
result <- fromJSON(file = "input.json")
Convert JSON file to a data frame.
json_data_frame <- as.data.frame(result)
print(json_data_frame)
當(dāng)我們執(zhí)行上面的代碼，它產(chǎn)生以下結(jié)果 -
id, name, salary, start_date, dept
1 1 Rick 623.30 2012-01-01 IT
2 2 Dan 515.20 2013-09-23 Operations
3 3 Michelle 611.00 2014-11-15 IT
4 4 Ryan 729.00 2014-05-11 HR
5 NA Gary 843.25 2015-03-27 Finance
6 6 Nina 578.00 2013-05-21 IT
7 7 Simon 632.80 2013-07-30 Operations
8 8 Guru 722.50 2014-06-17 Finance
