getting data frame names from list inside a loop

Question

I retrieve all dataframes from environment and then do some stuff:

dfs <- Filter(function(x) is(x, "data.frame"), mget(ls()))

names(dfs)

"customers"
"sales"
"campaigns"

First thing I need to extract is object name inside a loop:

for (df in dfs) {
  df_name <- deparse(substitute(df))
  # do some stuff
  # do some more stuff
  print(df_name)
}

But instead data frame names to operate I get:

"df"
"df"
"df"

I've tested a function inside the loop too:

find_name <- function(df) {
  df_name_is <- substitute(df)
  return(df_name_is)
}

But the output is:

df
df
df

looping through names of df gets me the colnames of every df, not the df name itself.

any hint will be much appreciated

looping through names of df gets me the colnames of every df — Forge
– Forge, Commented Feb 14, 2017 at 14:43
bouncyball print(df) returns the complete content for every df but I just need the name — Forge
– Forge, Commented Feb 14, 2017 at 15:32

useRj · Accepted Answer · 2017-02-14 17:32:07Z

5

If you don't mind use loop by counter (length) instead of names this is a valid approach:

for (i in 1:length(dfs)) {

print(names(dfs)[i])

 }

answered Feb 14, 2017 at 17:32

useRj

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Comments

drmariod · Accepted Answer · 2017-02-14 15:53:30Z

2

What about iterating over the names?!

for (df_name in names(dfs)) {
  print(df_name)
  df_obj <- dfs[[df_nmae]]
}

answered Feb 14, 2017 at 15:53

drmariod

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