python 3.x - multiprocessing with delay of second function -

i have function write data text file, second function pull data same text file , show graph. want start second function few seconds after first function started , running both till both completed. in way can live graph. code have written below starts 2 functions simultaneously second function cannot see text file. need bit of delay second function give time first function create text file.

however because second function (live_graph) needs not pull data text file parameters (ex. title of graph) 1st function not sure if correct way proceed, seems not possible "key" function; got "key not defined". maybe have write text file parameters?

from multiprocessing import process import time  def writing():         numentries = 0     text in get_all(newlista, "sentence", "text"):          if text.lower().startswith( key.lower().split(none, 1)[0] ):             pass         elif len(text) > 500:             pass         elif len(text) < 80:             pass         else:             on_data(text)              numentries += 1       def live_graph():   #pull data text.txt    time.sleep(5)   if __name__=='__main__':   p1 = process(target = writing)  p1.start()  p2 = process(target = live_graph)  p2.start()   

you want use multiprocessing.queue

for example (from docs):

from multiprocessing import process, queue  def f(q):     q.put([42, none, 'hello'])  if __name__ == '__main__':     q = queue()     p = process(target=f, args=(q,))     p.start()     print q.get()    # prints "[42, none, 'hello']"     p.join() 

you use in code this:

from multiprocessing import process, queue import time   def writing(q):     keep_running = true     numentries = 0     key = 'something, assume'     text in get_all(newlista, "sentence", "text"):         # python lets nice comparisons this,         # like. , make more         # obvious want lines of length between         # 80 , 500 characters         if 80 < len(text) < 500:             firstword = key.lower().split(none, 1)[0]             if text.lower().startswith(firstword):                                # note: *essential* in `on_data(text)`                 # after writing file run `file.flush()`                 # or close file, otherwise data *may*                 # buffered , hence, missing, when go read                 # file                 on_data(text)                 q.put(keep_running)      keep_running = false     q.put(keep_running)  def live_graph(q):     keep_running = true     while keep_running:         keep_running = q.get()         # graph updates here   if __name__=='__main__':  q = queue()  p1 = process(target = writing, args=(q,))  p1.start()  p2 = process(target = live_graph, args=(q,))  p2.start()