Convert Rnw (Sweave) to R Markdown (Rmd)

rnw2rmd.py

#
# A very cheap-and-cheerful way to convert Rnw (Latex-R-Sweave) into Rmd (R Markdown).
#
# Probably doesn't work with any generality but may be nice to try anyway.
# NOTE: You'll have to do a whole bunch of manual tweaking of the file afterwards, 
# because the Rmd will still contain lots of LATEX code.


from tkinter import filedialog
from tkinter import *
import os
import re
 
root = Tk()
fname  =  filedialog.askopenfilename(initialdir = ".",title = "Select file",
                                     filetypes = (("R Sweave","*.Rnw"),("all files","*.*")))

if not fname or fname=="": exit

sourcef = fname

targetf = sourcef.replace('.Rnw','.Rmd')

assert targetf!=sourcef

assert not os.path.exists(targetf)


with open(sourcef,'r') as f:
    source = f.read()


res = re.findall(r'<<([^<>]*)>>=([^@]+)@',source)

rmd = re.sub(r'<<([^<>]*)>>=([^@]+)@',r'```{r \1}\2\n```\n',source)

with open(targetf,'w') as f:
    f.write(rmd)