从 R 中的 data.table 中删除多列

在本文中，我们将看到如何在 R 编程语言中从 data.table 中删除多个列。

创建 data.table 进行演示：

R

# load the data.table package
library("data.table")
  
# create a data.table with 4 columns
# they are id,name,age and address
  
data = data.table(id = c(1,2,3) ,
                  name = c("sravan","bobby","satwik"),
                  age = c(23,21,17),
                  address = c("kakumanu","ponnur","hyd"))
  
# display
data

输出：

这里我们将使用索引运算符[] 删除多列

Syntax: data[ ,’:='(column1 = NULL, column2 = NULL, column n=NULL)]  

where

• data is the input data.table
• column is the columns to be removed
• := is the operator to be loaded in the data.table

示例 1：从 data.table 中删除多列的 R 程序

电阻

# load the data.table package
library("data.table")
  
# create a data.table with 4 columns
# they are id,name,age and address
  
data = data.table(id = c(1,2,3),
                  name = c("sravan","bobby","satwik"),
                  age = c(23,21,17),
                  address = c("kakumanu","ponnur","hyd"))
  
# remove age , name and address columns
data[ ,':='(age = NULL, address = NULL, name=NULL)]  
  
# display
data

输出：

示例 2：仅从 data.table 中删除一列

电阻

# load the data.table package
library("data.table")
  
# create a data.table with 4 columns
# they are id,name,age and address
  
data = data.table(id = c(1,2,3),
                  name = c("sravan","bobby","satwik"),
                  age = c(23,21,17),
                  address = c("kakumanu","ponnur","hyd"))
  
# remove id column
data[ ,':='(id=NULL)]  
  
# display
data

输出：

示例 3： R 程序删除所有列

电阻

# load the data.table package
library("data.table")
  
# create a data.table with 4 columns
# they are id,name,age and address
  
data = data.table(id = c(1,2,3),
                  name = c("sravan","bobby","satwik"),
                  age = c(23,21,17),
                  address = c("kakumanu","ponnur","hyd"))
  
# remove all columns
data[ ,':='(id=NULL,age = NULL, address = NULL, name=NULL)]  
  
# display
data

输出：

Null data.table (0 rows and 0 cols)