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How can you concatenate two dataframes in r so that a new column appears in the resulting dataframe indicating the origin dataframe?

Suppose I have two dataframes, df1 and df2, and they contain the same column headers, so

df1 = 
price size
10    40

and

df2 = 
price size
20    50

I would like to combine these two dataframes so that the resulting dataframe, price size origin

10 40 df1
20 50 df2

Thoughts?

+3


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2 answers


The easiest way I see is (if you have a lot of datasets named df

+ some number, although you can choose another regex pattern as well) to get them all from the global environment and use the do.call/rbind

combination

res <- do.call(rbind, mget(ls(pattern = "^df\\d+$")))
res
#     price size
# df1    10   40
# df2    20   50


If you prefer the source to be a column instead of row names, you could simply do

res$origin <- row.names(res)
+2


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You can also do



library(tidyr)
unnest(mget(paste0('df', 1:2)), origin)
#    origin price size
#1   df1    10   40
#2   df2    20   50
+1


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