Reputation: 23
I been trying to figure out this for ages, but wondering if anyone might know how I can pass the s
variable to the pool without making it into an argument?
import ctypes
import multiprocessing as mp
import os
def worker1(n):
k = n*3
print(k)
print(s)
# print(ctypes_int.value)
if __name__ == '__main__':
# global s
somelist = [1,2,3]
# ctypes_int = mp.Value(ctypes.c_wchar_p , "hi")
s = "TESTING"
# worker1(1)
p = mp.Pool(1)
p.map(worker1,somelist)
This is the error I am getting:
3
6
9
multiprocessing.pool.RemoteTraceback:
"""
Traceback (most recent call last):
File "C:\Program Files\Python\Python37\lib\multiprocessing\pool.py", line 121, in worker
result = (True, func(*args, **kwds))
File "C:\Program Files\Python\Python37\lib\multiprocessing\pool.py", line 44, in mapstar
return list(map(*args))
File "C:\Users\light\AppData\Local\Temp\tempCodeRunnerFile.python", line 10, in worker1
print(s)
NameError: name 's' is not defined
"""
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "C:\Users\light\AppData\Local\Temp\tempCodeRunnerFile.python", line 21, in <module>
p.map(worker1,somelist)
File "C:\Program Files\Python\Python37\lib\multiprocessing\pool.py", line 268, in map
return self._map_async(func, iterable, mapstar, chunksize).get()
File "C:\Program Files\Python\Python37\lib\multiprocessing\pool.py", line 657, in get
raise self._value
NameError: name 's' is not defined
Upvotes: 2
Views: 1772
Reputation: 39354
You can pass your variable along with each item in somelist
:
import multiprocessing as mp
def worker1(p):
n,s = p
k = n*3
print(k)
print(s)
if __name__ == '__main__':
somelist = [1,2,3]
s = "TESTING"
p = mp.Pool(1)
p.map(worker1,[(n,s) for n in somelist])
The parameter (n,s)
gets passed as p
and I unpack it into n,s
.
Upvotes: 3