Coerce variables in data frame to appropriate format

Question

I\'m working a data frame which consists of multiple different data types (numerics, characters, timestamps), but unfortunately all of them are received as characters. Hence I n

Answer 1

The recent file readers like data.table::fread or the readr package do a pretty decent job in identifying and converting columns to the appropriate type.

So my first reaction was to suggest to write the data to file and read it in again, e.g.,

library(data.table)
fwrite(df, "dummy.csv")
df_new <- fread("dummy.csv")
str(df_new)

Classes ‘data.table’ and 'data.frame':    4 obs. of  2 variables:
 $ val1: int  1 2 3 4
 $ val2: chr  "A" "B" "C" "D"
 - attr(*, ".internal.selfref")=

or without actually writing to disk:

df_new <- fread(paste(capture.output(fwrite(df, "")), collapse = "\n"))

However, d.b's suggestions are much smarter but need some polishing to avoid coercion to factor:

df[] <- lapply(df, type.convert, as.is = TRUE)
str(df)

'data.frame': 4 obs. of  2 variables:
 $ val1: int  1 2 3 4
 $ val2: chr  "A" "B" "C" "D"

or

df[] <- lapply(df, readr::parse_guess)