CODEWITHSUNDEEP
rlistdataframe
Danielle
Danielle

Reputation: 795

Change all cases of elements and headers in a list of data frames to lowercase

I have a list of data frames:

mylist<-list(df1=data.frame(Var1=c("A","b","c"), var2= 
c("a","b","c")), df2= data.frame(var1 = c("a","B","c"), 
VAr2=c("A","B","C")))

I would like to change all cases within the column headings and each element of a string to lowercase. (This way when I merge data frames all variables merge correctly and 'cat' vs "Cat' are not read as different entries).

The output would look like:

mylist<-list(df1=data.frame(var1=c("a","b","c"), var2= 
c("a","b","c")), df2= data.frame(var1 = c("a","b","c"), 
var2=c("a","b","c")))

I have tried the following:

cleandf <- lapply(mylist, function(x) tolower(mylist[x])

Upvotes: 2

Views: 92

Answers (1)

markus
markus

Reputation: 26343

Here is a similar approach to Masoud's answer

lapply(mylist, function(x) {
  names(x) <- tolower(names(x))
  x[] <- lapply(x, tolower)
  x
})
#$df1
#  var1 var2
#1    a    a
#2    b    b
#3    c    c

#$df2
#  var1 var2
#1    a    a
#2    b    b
#3    c    c

The first lapply iterates over your list. For each data frame - represented by the x - we first change its column names. The second lapply then applies tolower to each column of your data frames.

Upvotes: 1

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