import re

def func_replace(m):
    nr_ver = m.group(4)
    nr = int(nr_ver)
    new_nr = nr + 1
    new_nr_str = str(new_nr)
    return "(\d{4}).(\d).(\d{2})." + new_nr_str + ".a"

f = open("/Users/roag75mini/Desktop/work/Engineering/Runner/proj.ios_mac/mac/Info.plist" , "r+")
text = f.read()
new_text = re.sub("(\d{4}).(\d).(\d{2}).(\d+)", func_replace, text)
f.seek(0)
f.truncate()
f.write(new_text)
f.close()