azadag
5/4/2020 - 12:28 AM

list all factor levels of a dataframe

data %>% purrr:map(levels)
#Or to first factorize everything:
data %>% dplyr::mutate_all(as.factor) %>% purrr:map(levels)

# or 
data %>% summarise_each(funs(list(levels(.))))

# how to get the lengths:
data %>% map(levels) %>% map(length)