Thread starts without button event Tkinter

Question

I have the following piece of code and want to start the thread once I enter a string in the text box, however as soon as I run the program the thread starts executing, any ideas? Shouldn't the thread start when the method that creates it get executed?

class FuncThread(threading.Thread):

    def __init__(self, target, *args):
        self._target = target
        self._args = args
        threading.Thread.__init__(self)

    def run(self):
        self._target(*self._args)


class BuildGui():         

    def show_entry_fields(self, 
                      release_version=None):
        print("Release Version: %s\n" % release_version)
        pattern = re.compile('^\d*\.\d*\.\d*$')
        if re.match(pattern, release_version):
            self.thread_execute_build(release_version=release_version)
        else:
            print "Enter a valid release version (e.g. 5.3.2)"
            e1.delete(0, 'end')


    def execute_build(self,
                  release_version=None):
        cmd_build_jenkins = 'java -jar jenkins-cli.jar -s http://xyz:8080/ build "New ESW build" -s -p "release_version"=' +  str(release_version)
        os.system(cmd_build_jenkins)

    def thread_execute_build(self, 
                         release_version=None):
        self.build_thread = FuncThread(self.execute_build, release_version)
        self.build_thread.start()

if __name__ == '__main__':

    master = Tk()
    Label(master, text="Release Version").grid(row=0)

    e1 = Entry(master)

    e1.grid(row=0, column=1)

    gui = BuildGui()
    Button(master, text='Quit', command=master.quit).grid(row=3, column=0, sticky=W, pady=4)
    Button(master, text='Show', command=gui.show_entry_fields(release_version=e1.get())).grid(row=3, column=1, sticky=W, pady=4)

    mainloop()

score 2 · Accepted Answer · answered Sep 06 '16 at 09:14

I would say you need to chnage:

Button(master, text='Show', command=gui.show_entry_fields(release_version=release_version)).grid(row=3, column=1, sticky=W, pady=4)

To:

Button(master, text='Show', command=lambda:gui.show_entry_fields(release_version=release_version)).grid(row=3, column=1, sticky=W, pady=4)

The lambda basically allows you to pass arguments without calling the function. Let me know if that helps.

Thread starts without button event Tkinter

1 Answers1