How to use loop function to rename multiple files' name after read them in R?

Question

I have multiple files under the folder of "rawdata", after read them and assigned them as seperated dataset, i also want to rename them from "dataset 1 a.csv" to "dataset1".

I wrote the code that achieve the first goal,using the first loop read all files as a list, then use the second loop to unset the list: ldf. But I don't know where I should add the code to let R change all file's name at once? I tried to add str_replace_all (names(ldf)," ", "-") at different places, but all returned wrong outputs, and it cannot solve the issue of getting rid of ".csv". Thanks a lot~~

Here is my code:

datanames<-list.files(here("rawdata"))

ldf<-list()

for (i in (datanames)){
  ldf[[i]]<-import(here("rawdata",i))
    for (j in names(ldf)){
      assign(j,ldf[[j]], .GlobalEnv)
    }
}