Files
h2inc-old/Multiprocessing test/calc_pi_win.py
2018-02-20 11:34:52 +01:00

134 lines
3.6 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
ZetCode Tkinter e-book
This script produces a long-running task of calculating
a large Pi number, while keeping the GUI responsive.
This is an example written for Windows.
Author: Jan Bodnar
Last modified: January 2016
Website: www.zetcode.com
"""
from tkinter import (Tk, BOTH, Text, E, W, S, N, END,
NORMAL, DISABLED, StringVar)
from tkinter.ttk import Frame, Label, Button, Progressbar, Entry
from tkinter import scrolledtext
from multiprocessing import Process, Manager, Queue
from queue import Empty
from decimal import Decimal, getcontext
DELAY1 = 80
DELAY2 = 20
# Queue must be global
q = Queue()
class Example(Frame):
def __init__(self, parent):
Frame.__init__(self, parent, name="frame")
self.parent = parent
self.initUI()
def initUI(self):
self.parent.title("Pi computation")
self.pack(fill=BOTH, expand=True)
self.grid_columnconfigure(4, weight=1)
self.grid_rowconfigure(3, weight=1)
lbl1 = Label(self, text="Digits:")
lbl1.grid(row=0, column=0, sticky=E, padx=10, pady=10)
self.ent1 = Entry(self, width=10)
self.ent1.insert(END, "4000")
self.ent1.grid(row=0, column=1, sticky=W)
lbl2 = Label(self, text="Accuracy:")
lbl2.grid(row=0, column=2, sticky=E, padx=10, pady=10)
self.ent2 = Entry(self, width=10)
self.ent2.insert(END, "100")
self.ent2.grid(row=0, column=3, sticky=W)
self.startBtn = Button(self, text="Start",
command=self.onStart)
self.startBtn.grid(row=1, column=0, padx=10, pady=5, sticky=W)
self.pbar = Progressbar(self, mode='indeterminate')
self.pbar.grid(row=1, column=1, columnspan=3, sticky=W+E)
self.txt = scrolledtext.ScrolledText(self)
self.txt.grid(row=2, column=0, rowspan=4, padx=10, pady=5,
columnspan=5, sticky=E+W+S+N)
def onStart(self):
self.startBtn.config(state=DISABLED)
self.txt.delete("1.0", END)
digits = int(self.ent1.get())
accuracy = int(self.ent2.get())
self.p1 = Process(target=generatePi, args=(q, digits, accuracy))
self.p1.start()
self.pbar.start(DELAY2)
self.after(DELAY1, self.onGetValue)
def onGetValue(self):
if (self.p1.is_alive()):
self.after(DELAY1, self.onGetValue)
return
else:
try:
self.txt.insert('end', q.get(0))
self.txt.insert('end', "\n")
self.pbar.stop()
self.startBtn.config(state=NORMAL)
except Empty:
print("queue is empty")
# Generate function must be a top-level module funtion
def generatePi(q, digs, acc):
getcontext().prec = digs
pi = Decimal(0)
k = 0
n = acc
while k < n:
pi += (Decimal(1)/(16**k))*((Decimal(4)/(8*k+1)) - \
(Decimal(2)/(8*k+4)) - (Decimal(1)/(8*k+5))- \
(Decimal(1)/(8*k+6)))
k += 1
q.put(pi)
def main():
root = Tk()
root.geometry("400x350+300+300")
app = Example(root)
root.mainloop()
if __name__ == '__main__':
main()