Hi,
System: Python 3.6, Ubuntu Linux 17.10
I am trying to get tkinter to return a number from a window, which then
sets how many times to print a sign.
The code does not wait till the function returns a value, resulting in
the signcount variable in having a None value, giving an output like
below. Note that the output "line 64 ### The required number of signs
is 5 ###" only occurs after a number is input.
I can use an input statement to get the desired output, but that's not
good having to go to the terminal to enter the response. How can I get
the printSign code to wait till getcount() returns it's value?
Any help greatly appreciated.
Regards, Chris Roy-Smith
chris@chris-X451MA:~/Scripts/python3/dvms$ ./debug1.py
line 27 ### required sign count for D is None ###
Exception in Tkinter callback
Traceback (most recent call last):
File "/usr/lib/python3.6/tkinter/__init__.py", line 1702, in __call__
return self.func(*args)
File "./debug1.py", line 28, in printSign
for x in range(signcount):
TypeError: 'NoneType' object cannot be interpreted as an integer
line 64 ### The required number of signs is 5 ###
Code:
#!/usr/bin/python3
from tkinter import *
import os
from reportlab.lib.units import cm
from reportlab.lib.pagesizes import A4
from reportlab.pdfgen import canvas
from reportlab.lib.utils import ImageReader
def printSign():
global gc, packages, rows
myCanvas = canvas.Canvas("Signs.pdf", pagesize=A4)
width, height = A4 #keep for
myCanvas.rotate(90)
myCanvas.setFillColorRGB(0,0,0)
myCanvas.setFont("Helvetica-Bold", 400)
TopMargin=-20
LeftMargin=1
Width=14
Height=19
VertPos=-15
Bottom=-1
a=[" " for i in range(rows)]
i=0
sign=0
for line in packages:
signcount=getcount(line[1])
print('line 27 ### required sign count for {} is {}
###'.format(line[1], str(signcount)))
for x in range(signcount):
#draw rectangle
myCanvas.rect(LeftMargin*cm+Width*sign*cm, TopMargin*cm,
Width*cm, Height*cm, stroke=0, fill=1)
myCanvas.drawCentredString((LeftMargin+(0.5*Width))*cm+(Width*sign)*cm,
VertPos*cm, line[0])
if sign==1:
myCanvas.showPage()
sign=0
myCanvas.rotate(90)
i+=1
else:
sign+=1
i+=1
myCanvas.showPage()
myCanvas.save()
if os.name == "posix":
os.popen("evince %s" % ("Signs.pdf"))
if os.name == "nt":
os.startfile('Signs.pdf')
def getcount(SignText):
global gc,e
gc=Toplevel(master)
MsgText='How many copies of {} do you want to print?'.format(SignText)
Label(gc, text=MsgText).grid(row=0, column=0, sticky=(W,E))
e = Entry(gc)
e.grid(row=0, column=1)
Button(gc, text='Okay', command=ReturnCount).grid(row=1, column=0,
sticky=(W,E))
Button(gc, text='Cancel', command=gc.destroy).grid(row=1, column=1,
sticky=(W,E))
def ReturnCount():
global gc,e
b0=e.get()
if b0 == None:
b0=0
gc.destroy()
print('line 64 ### The required number of signs is {}
###'.format(b0))
return b0
master = Tk()
master.title("Testing")
packages = [[0,'D','drill'],[1,'J','Jointer'],[2,'B','Bandsaw']]
rows = 3
b2 = Button(master, text="Print Signs", command=printSign).grid(row=4,
column=0, sticky=(W,E), padx=5, pady=5)
b3 = Button(master, text="Quit", command=master.destroy).grid(row=4,
column=3, sticky=(W,E))
master.mainloop()
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