Hello,

Using Jim's lapply(., is.factor) but simplified, you could do


df1 <- df
i <- sapply(df1, is.factor)
df1[i] <- lapply(df1[i], as.character)


a one-liner modifying df, not df1 is


df[sapply(df, is.factor)] <- lapply(df[sapply(df, is.factor)], as.character)


Hope this helps,

Rui Barradas

Às 11:03 de 19/09/21, Luigi Marongiu escreveu:
Thank you Jim, but I obtain:
```
str(df)
'data.frame': 5 obs. of  3 variables:
  $ region : Factor w/ 5 levels "A","B","C","D",..: 1 2 3 4 5
  $ sales  : num  13 16 22 27 34
  $ country: Factor w/ 5 levels "a","b","c","d",..: 1 2 3 4 5
df1<-df[,!unlist(lapply(df,is.factor))]
str(df1)
  num [1:5] 13 16 22 27 34
df1
[1] 13 16 22 27 34
```
I was expecting
```
str(df)
'data.frame': 5 obs. of  3 variables:
  $ region : char "A","B","C","D",..: 1 2 3 4 5
  $ sales  : num  13 16 22 27 34
  $ country: char "a","b","c","d",..: 1 2 3 4 5
```

On Sun, Sep 19, 2021 at 11:37 AM Jim Lemon <drjimle...@gmail.com> wrote:

Hi Luigi,
It's easy:

df1<-df[,!unlist(lapply(df,is.factor))]

_except_ when there is only one column left, as in your example. In
that case, you will have to coerce the resulting vector back into a
one column data frame.

Jim

On Sun, Sep 19, 2021 at 6:18 PM Luigi Marongiu <marongiu.lu...@gmail.com> wrote:

Hello,
I woul dlike to remove factors from all the columns of a dataframe.
I can do it n a column at the time with
```

df <- data.frame(region=factor(c('A', 'B', 'C', 'D', 'E')),
                  sales = c(13, 16, 22, 27, 34), country=factor(c('a',
'b', 'c', 'd', 'e')))

new_df$region <- droplevels(new_df$region)
```

What is the syntax to remove all factors at once (from all columns)?
For this does not work:
```
str(df)
'data.frame': 5 obs. of  3 variables:
  $ region : Factor w/ 5 levels "A","B","C","D",..: 1 2 3 4 5
  $ sales  : num  13 16 22 27 34
  $ country: Factor w/ 5 levels "a","b","c","d",..: 1 2 3 4 5
df = droplevels(df)
str(df)
'data.frame': 5 obs. of  3 variables:
  $ region : Factor w/ 5 levels "A","B","C","D",..: 1 2 3 4 5
  $ sales  : num  13 16 22 27 34
  $ country: Factor w/ 5 levels "a","b","c","d",..: 1 2 3 4 5
```
Thank you

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