操作列表内的数据框 [英] Manipulate data frame inside a list

问题描述

这大概是一个简单的问题，但是我一直找不到答案。
我想删除列表内数据框的一列。

this is presumably a simple question, but I have been unable to find an answer. I want to delete a column of a dataframe that is inside a list.

x1<- rnorm(100,0,1)
x2<- rnorm(100,0,1)
x3<- rnorm(100,0,1)
x4 <- rnorm(100,0,1)

df1 <- data.frame(x1,x2,x3)
df2 <- data.frame(x4)

l1 <- list(df1,df2)

l1[1]

data.frame(l1[1])[,-1]

l1[1] <- data.frame(l1[1])[,-1]

考虑以下示例，其中两个数据帧df1和df2在列表l1中。
我想从df1中删除列x1。如果这只是一个数据帧，那么这很简单。
但是一旦进入列表，我不确定如何操作此数据框。
当我尝试在上一个语句中覆盖它时，出现错误。

Consider this example in which two dataframes, df1 and df2, are in list, l1. I want to delete column x1 out of df1. This is trivial to do if this is just a dataframe. But once inside a list, I am not sure how to manipulate this dataframe. When I try to overwrite it in the last statement, I am getting an error.

我的实际问题是列表中有大约100个数据帧，而大约10％其中有一个我需要删除的附加列。我可以轻松地识别它们，但我不知道如何操纵它们。

My actual problem has about 100 dataframes in a list and about 10% of them have an additional column that I need to delete. I can easily identify them with an lapply statement, but I don't know how to manipulate them.

谢谢！

推荐答案

代替

l1[1] <- data.frame(l1[1])[,-1]

使用

l1[[1]] <- data.frame(l1[1])[,-1]

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