user interface - Python Execution Order with GUI -


i'm having issues following code. first time i'm working gui , it's been while since i've worked python well. when try execute solfield function button, yields no output.

from tkinter import * import math  master = tk()  n = float() = float()   def solfield():     pass    label_coils = label(text='number of coils per meter', textvariable=n) label_coils.grid() coils = entry(master) coils.grid()  label_current = label(text='current in amps', textvariable=i) label_current.grid() current = entry(master) current.grid()  calculate_button = button(text='calculate', command=solfield()) calculate_button.grid() label_bfield = label(text='b field in +z direction') label_bfield.grid() label_result = label(text='solfield') label_result.grid()   master.title('coil gun simulation') master.mainloop()   def solfield():     mu0 = math.pi*4e-7     solfield = mu0*n*i     print solfield

any other tips appreciated well, there more coding me do.

this has been solved. if interested, here code after several fixes made:

from tkinter import * import math  master = tk()  label_coils = label(text='number of coils per meter') label_coils.grid() coils = entry(master) coils.grid()  label_current = label(text='current in amps') label_current.grid() current = entry(master) current.grid()    def solfield():     mu0 = math.pi*4e-7     n = float(coils.get())     = float(current.get())     fieldmag = mu0*n*i     print fieldmag  calculate_button = button(text='calculate', command=solfield) calculate_button.grid() label_bfield = label(text='b field in +z direction') label_bfield.grid() label_result = label(text='solfield') label_result.grid()    master.title('coil gun simulation') master.mainloop()

the problem here:

calculate_button = button(text='calculate', command=solfield())

to pass function solfield command, use name:

calculate_button = button(text='calculate', command=solfield)

what you're doing calling function, , passing return value of function command.

since defined solfield above do-nothing function, return value none, you're telling calculate_button command=none, , it's doing nothing.

meanwhile, sethmmorton pointed out (but deleted):

you have 2 functions named solfield, , naming variable solfield in 1 of solfield functions. remove empty function (the 1 pass), , using different variable name in remaining function.

this isn't causing actual problem, it's adding confusion makes harder find problem. (for example, if hadn't included excess empty definition of solfield @ all, have gotten nameerror in incorrect line, have made things easier debug.)

putting together, should is:

  1. get rid of empty (pass-only) definition of solfield.
  2. move real implementation of solfield above point build gui.
  3. don't name local variable solfield within function.
  4. pass solfield, not solfield() command calculate_button.

Comments

Post a Comment

Popular posts from this blog

jquery - How can I dynamically add a browser tab? -

since using iframes house external pages are, accounts "not preferred method" , disallowed sites (flickr, one), want dynamically generate browser tabs. e.g., when user submits form, want dynamically generate tab on browser in response submitted. e.g., might want add new tab url like: http://www.bigsurgarrapata.com/contact how in jquery? you want form target attribute action attribute. http://www.w3schools.com/tags/att_form_target.asp browsers have ultimate control on result of target attribute open new tab value of _blank. <form action="contact_submit.php" target="_blank" method="post">
Read more

node.js - Getting the socket id,user id pair of a logged in user(s) -

i have web application done using node js , in it,i have authentication system requires users log in before can access pages. have 2 pages,the homepage , updates page. from read docs,a new socket id issued when user opens tab in browser. me being admin,i know socket id of logged in user , more so,the socket id,logged in user id pair logged in users. what method can use socket id,logged in user id pair make sure broadcast realtime info users online?.
Read more

keyboard - C++ GetAsyncKeyState alternative -

i using windows.h library's getasynckeystate function define key pushed on keyboard . here program returns int value of pushed key example. #include <iostream> #include <windows.h> using namespace std; int main (){ char i; for(i=8;i<190;i++){ if(getasynckeystate(i)== -32767){ cout<<int (i)<<endl; } } return 0; } but trying make opengl simple game , function appeared slow . there function not need cycle 180 times , if statement . thanks you're trying make opengl game, you're going use glfw. if that's case can away using glfwgetkey() such: if (glfwgetkey(glfw_key_up) == glfw_press) {...} if (glfwgetkey(glfw_key_down) == glfw_press) {...} that method nicely explained in tutorial 6 opengl-tutorial.org . should start first tutorial of beginners tutorials , later intermediate tutorials . if you're going make win32 window can listen wm_keydown or wm_keyup messages , virtua
Read more