email backup. Parts of my backup system

backup.py

def mkdir(path):
    if not os.path.isdir(path):
        os.makedirs(path)

def ln(source,target):
    target=target.replace(":","%%%%%")
    # print("{} => {}".format(source,target))
    if os.path.isfile(target):
        os.remove(target)
    os.symlink(source,target)

def createfolders(relpath,path,bp):
    oldpath="{}/{}".format(path,relpath)
    newpath="{}/{}".format(bp,relpath)
    # print(oldpath)
    # print(newpath)
    mkdir(newpath)
    contents = os.listdir(oldpath)# if f.is_dir() ]█
    for f in contents:
        newrelpath="{}/{}".format(relpath,f)
        oldabspath="{}/{}".format(path,newrelpath)

        # print(newrelpath)
        # print(oldabspath)
        if os.path.isdir(oldabspath):
            createfolders(newrelpath,path,bp)
        else:
            source=oldabspath
            target="{}/{}".format(bp,newrelpath)
            ln(source,target)

def mailbackup(bp):
    path="~"
    path=os.path.expanduser(path)
    relpath="mail"
    createfolders(relpath, path,bp)

def run(command):
    output=subprocess.call(['sh', '-c', command])

if os.path.isdir(os.path.expanduser("~/mail")):
    comment("creating symlinked folder for rsync.")
    #fix this shit if there is no more need to replace the : in filenames
    bp="/data/data/com.termux/files/usr/tmp/mailbackuptemp"
    mailbackup(bp)
    comment("Copying mails to drive")
    run("rsync {}/mail/ ~/drive/mail -aLv --delete --progress --size-only".format(bp))
    comment("remove temporary directory")
    shutil.rmtree(bp)