如何将数据列保留为数据帧-Howtokeepacolumnofdataframeasdataframe

10  

data[, 1, drop = FALSE] will do the trick.

data [,1,drop = FALSE]可以解决问题。

9  

Use list subsetting which will return a data frame:

使用将返回数据框的列表子集:

data[1]

Produces

  Sepal.Length
1          5.1
2          4.9
3          4.7
4          4.6
5          5.0
6          5.4
# ... omitted rows

When you use only one argument to [ with data frames it subsets data frames as lists, where each column is an element. It also preserves attributes, so the subset of the data frame is also a data frame.

当你只使用一个参数[与数据帧时,它将数据帧子集为列表,其中每列是一个元素。它还保留属性,因此数据帧的子集也是数据帧。