从包含 R 中每行列表中的列表的数据帧的每一行中提取一个参数

Question

I have a dataframe with one column where each row contains a list, which in itself contains a list.

This looks something like this per row: list(statistic = c(x = 10.69), parameter = c(df = 4.63), p.value = c(P = 0.05))

To explain the structure of df somehow more:

row1<-list(statistic = c(x = 10.69), parameter = c(df = 4.63), p.value = c(P = 0.05)) 
row2<-list(statistic = c(x = 10.69), parameter = c(df = 4.63), p.value = c(P = 2.5))
...
row300<-row1<-list(statistic = c(x = 10.69), parameter = c(df = 4.63), p.value = c(P = 4.6))  

df<-rbind(row1, row2, ... , row300) #this is the dataframe I have 

The only thing of interest for me is the p-value which is why I would like to extract this somehow so that ideally, I want to create a dataframe that has the same amount of rows as the original dataframe and each row contains the p.value, meaning what's in the list for p.value so " P = 0.05 " in this case.

So to come back to the above code example: what I need is a new dataframe that contains the extracted p.value in each row so that the output of calling a row would be

df2[1] 0.05 df2[2] 2.5 ... df2[300] 4.6

Extracting the value I need for one row works fine like this: df[[1]][[1]][['p.value']]

However when I want to do this for each of the 300 rows of the dataframe it does not work. I was thinking about a for loop where I extract each p.value per row and subset them in a new dataframe:

x<-1:300
for(i in x){
  one<-data.frame
  one<-rbind(df[[1]][[i]][['p.value']])
}

Answer 1

尝试像这样使用sapply -

p_values <- sapply(df, function(x) x[[1]][['p.value']])