subprocess.call() interacting with GUI (Tkinter)

Question

Is there any way to use subprocess.call() or subprocess.Popen() and interact with the stdin via Tkinter's Entry widget, and output the stdout to a Text widget?

Im not really sure how to approach something like this, as i am new to using the subprocess module.

Answer 1

Think I've got the basics of using an Entry as stdin to subprocess. You may have to jiggle it about for your own needs (re: output to Text widget).

This example calls a test script:

# test.py:

#!/usr/bin/env python
a = raw_input('Type something!: \n') #the '\n' flushes the prompt
print a

that simply requires some input (from sys.stdin ) and prints it.

Calling this and interacting with it via a GUI is done with:

from Tkinter import *
import subprocess

root = Tk() 

e = Entry(root)
e.grid()

b = Button(root,text='QUIT',command=root.quit)
b.grid()

def entryreturn(event):
    proc.stdin.write(e.get()+'\n') # the '\n' is important to flush stdin
    e.delete(0,END)

# when you press Return in Entry, use this as stdin 
# and remove it
e.bind("<Return>", entryreturn)

proc = subprocess.Popen('./test.py',stdin=subprocess.PIPE)

root.mainloop()

Now whatever is typed into Entry e (followed by the Return key), is then passed via stdin to proc .

Hope this helps.

---

Also check this for ideas about stdout of subprocess question. You'll need to write a new stdout to redirect stdout to the textwidget, something like:

class MyStdout(object):
    def __init__(self,textwidget):
        self.textwidget = textwidget
    def write(self,txt):
        self.textwidget.insert(END,txt)

sys.stdout = MyStdout(mytextwidget)

but I would recommend reading other examples where people have achieved this.