Cannot Pool.map() function because of UnpickleableError? - python-2.7

Question

So I am trying to multi process function F. Which is accessed by a button press with tkinter.
def f(x):
global doom,results,info
doom = doom + 1
if check(x) == True:
results.add(x)
info.append(get_column_number(x))
j.step(1)
texx = "1/"+doom
s.configure(text=texx)
root.update()
The function is called within a function like so:
def dojob():
index = ['URLS'...]
pool = Pool(processes=4)
s.configure(text="Shifting Workload to cores..")
root.update()
pool.map(f, index)
The button is inside root window.
I get the following error:
Exception in thread Thread-2:
Traceback (most recent call last):
File "C:\Python27\lib\threading.py", line 808, in __bootstrap_inner
self.run()
File "C:\Python27\lib\threading.py", line 761, in run
self.__target(*self.__args, **self.__kwargs)
File "C:\Python27\lib\multiprocessing\pool.py", line 342, in _handle_tasks
put(task)
UnpickleableError: Cannot pickle <type 'tkapp'> objects
I do not even know what a pickle does? Help?
Here is the complete code:
from Tkinter import *
from ttk import *
from tkMessageBox import showinfo
from multiprocessing import Pool
import random
emails = set()
import urllib2
import urllib2 as urllib
########
CONSTANT_PAGECOUNT = 20
######
def f(x):
global doom,emails,info
doom = doom + 1
if check(x) == True:
print "",
emails.add(x)
info.append(get_column_number(x))
j.step(1)
texx = "Sk1nn1n "+str(doom)+'/'+str(CONSTANT_PAGECOUNT)+""
s.configure(text=texx)
root.update()
return 0
def f(x):
print ""
def showFile(site,info):
top = Toplevel()
top.title('Sites')
x = Text(top)
x.pack()
i=0
for site_url in site:
x.insert(END,site_url)
i=i+1
def get_column_number(url):
return True
def check(url):
return True
def getgoogleurl(search,siteurl=False,startr=0):
if siteurl==False:
return 'http://www.google.com/search?q='+urllib2.quote(search)+'&start='+str(startr)+'&oq='+urllib2.quote(search)
else:
return 'http://www.google.com/search?q=site:'+urllib2.quote(siteurl)+'%20'+urllib2.quote(search)+'&oq=site:'+urllib2.quote(siteurl)+'%20'+urllib2.quote(search)
def getgooglelinks(search,siteurl=False,startr=0):
#google returns 403 without user agent
headers = {'User-agent':'Mozilla/11.0'}
req = urllib2.Request(getgoogleurl(search,siteurl,startr),None,headers)
site = urllib2.urlopen(req)
data = site.read()
site.close()
#no beatifulsoup because google html is generated with javascript
start = data.find('<div id="res">')
end = data.find('<div id="foot">')
if data[start:end]=='':
#error, no links to find
return False
else:
links =[]
data = data[start:end]
start = 0
end = 0
while start>-1 and end>-1:
#get only results of the provided site
if siteurl==False:
start = data.find('<a href="/url?q=')
else:
start = data.find('<a href="/url?q='+str(siteurl))
data = data[start+len('<a href="/url?q='):]
end = data.find('&sa=U&ei=')
if start>-1 and end>-1:
link = urllib2.unquote(data[0:end])
data = data[end:len(data)]
if link.find('http')==0:
links.append(link)
return links
def rip(results=15,accuracy=16):
global e
keyword = ''+str(e.get())
if keyword.strip()=="":
s.configure(text="Please enter a keyword")
root.update()
return 0
linklist = []
counter = 0
doom = 0
while counter < results:
links = getgooglelinks(keyword,startr=counter)
for link in links:
if len(linklist) > CONSTANT_PAGECOUNT:
s.configure(text="Proccessing..")
root.update()
return linklist
else:
doom = doom + 1
linklist.append(link)
texx = str(doom)+"/"+str(CONSTANT_PAGECOUNT)
s.configure(text=texx)
root.update()
root.update()
counter = counter+accuracy
return linklist
def flip():
global e
emails = set()
info = []
keyword = ''+str(e.get())
if keyword.strip()=="":
s.configure(text="Please enter a keyword")
root.update()
return 0
s.configure(text="Generating index..")
root.update()
doom = -1
index = rip(CONSTANT_PAGECOUNT,10)
if 1:
try:
pool = Pool(processes=4)
#s.configure(text="Shifting Workload to cores..")
#root.update()
pool.map(f, index)
pool.close()
except:
print "The errors there.."
j.config(value=CONSTANT_PAGECOUNT)
if len(emails) > 0:
filepath='relavant_list_'+str(random.randint(1,9999))+'.emList.txt'
#print len(emails),
#print "emails found."
ggg = open(filepath,'a+')
for x in emails:
ggg.write(x+"\n")
showinfo(
str(len(emails))+" key word related sites found!",
" sites are saved in "+str(filepath)
)
showFile(emails,info)
s.configure(text=filepath)
else:
s.configure(text='No related sites found : (')
if __name__ == '__main__':
### CONSTANTS
version = '1.0'
### END CONSTANTS
root = Tk()
root.title('Program v'+version)
s = Style()
s.theme_use('default')
#print s.theme_names()
s.configure("black.Horizontal.TProgressbar", foreground='blue', background='blue')
j = Progressbar(root, style="black.Horizontal.TProgressbar", orient="vertical", length=200, mode="determinate", maximum=CONSTANT_PAGECOUNT, value=0)
j.pack(side='right',fill='y')
f = Frame(root)
x = Frame(f)
e = Entry(x,width=51)
s = Label(x,width=50,anchor='center',text='Waiting for task..')
Button(f,text='Generate List!',width=50,command=flip).pack(fill='both',expand=True)
s.pack(side='bottom',fill='y',expand=True)
e.pack(side='top',fill='both',expand=True)
x.pack(side='top',fill='y',expand=True)
f.pack(side='left',expand=True,fill="both")
root.mainloop()

Answer 1

You are leaking a tkinter object. Most likely because you are trying to update the interface from another process with the last line of f()
Update based on code
You have a name collision between your function f() and a variable f in your __main__ which gets assigned to your main window and causes the tkapp pickle error. Rename the function to def myfunc() or something. Also need to call pool.join() after pool.close()