使用部分列名在数据框中选择多列 [英] Selecting multiple columns in data frame using partial column name

问题描述

我有一个数据框，DF，列名都包含颜色名称:

I have a data frame, DF, and the column names all contain color names:

red_balloons green_balloons red_balls blue_balls green_hats red_horses yellow_things

我想做的是根据多个颜色名称选择多个列.我可以像这样一次选择一列:

What I would like to do is select multiple columns based on more than one color name. I can select one column at a time like this:

grep("red", colnames(DF))

但我无法弄清楚或找出如何选择多列.我试过这个:

But I cannot figure out or find out how to select multiple columns. I tried this:

grep(c("red", "blue"), colnames(DF))

但收到以下警告:

Warning message:
In grep(c("mean()", "std()"), colnames(L21), value = FALSE) :
   argument 'pattern' has length > 1 and only the first element will be used

建议?

推荐答案

您可以使用|"用于 grep 中的或"

You can use "|" for "or" in grep

grep("red|blue", DF, value=T)
# [1] "red_balloons" "red_balls"    "blue_balls"   "red_horses" 

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