Feb-23-2019, 11:09 PM
Hi all,
this is the first time I am using the parallel program in python, my program is shown below
this is the first time I am using the parallel program in python, my program is shown below
import numpy as np from time import time import multiprocessing as mp # Prepare data np.random.RandomState(100) arr = np.random.randint(0, 10, size=[200000, 5])#print(arr) data = arr.tolist() data[:5] # Define and function creation def howmany_within_range(row, minimum, maximum): """Returns how many numbers lie within `maximum` and `minimum` in a given `row`""" count = 0 for n in row: if minimum <= n <= maximum: count = count + 1 return count # Solution 2: Paralleization # Step 1: Init multiprocessing.Pool() pool = mp.Pool(mp.cpu_count()) # Step 2: `pool.apply` the `howmany_within_range()` results = [pool.apply(howmany_within_range, args=(row, 4, 8)) for row in data] # Step 3: Don't forget to close pool.close() # Step 4: Result print(results[:10])the execution of this program give the following error:
Error:Traceback (most recent call last):
File "<string>", line 1, in <module>
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 105, in spawn_main
exitcode = _main(fd)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 114, in _main
prepare(preparation_data)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 225, in prepare
_fixup_main_from_path(data['init_main_from_path'])
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 277, in _fixup_main_from_path
run_name="__mp_main__")
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 263, in run_path
pkg_name=pkg_name, script_name=fname)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 96, in _run_module_code
mod_name, mod_spec, pkg_name, script_name)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 85, in _run_code
exec(code, run_globals)
File "C:\109_personel\113_ARIMA_Tmin\Test_2.py", line 24, in <module>
pool = mp.Pool(mp.cpu_count())Traceback (most recent call last):
File "<string>", line 1, in <module>
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\context.py", line 119, in Pool
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 105, in spawn_main
context=self.get_context())
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\pool.py", line 176, in __init__
exitcode = _main(fd)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 114, in _main
self._repopulate_pool()
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\pool.py", line 241, in _repopulate_pool
prepare(preparation_data)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 225, in prepare
w.start()
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\process.py", line 112, in start
_fixup_main_from_path(data['init_main_from_path'])
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 277, in _fixup_main_from_path
self._popen = self._Popen(self)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\context.py", line 322, in _Popen
run_name="__mp_main__")
return Popen(process_obj) File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 263, in run_path
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\popen_spawn_win32.py", line 33, in __init__
prep_data = spawn.get_preparation_data(process_obj._name)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 143, in get_preparation_data
pkg_name=pkg_name, script_name=fname)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 96, in _run_module_code
_check_not_importing_main()
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\multiprocessing\spawn.py", line 136, in _check_not_importing_main
Traceback (most recent call last):
File "<string>", line 1, in <module>
mod_name, mod_spec, pkg_name, script_name)
File "C:\Users\lenovo\AppData\Local\Programs\Python\Python37\lib\runpy.py", line 85, in _run_code
is not going to be frozen to produce an executable.''')
RuntimeError:
An attempt has been made to start a new process before the
current process has finished its bootstrapping phase.
This probably means that you are not using fork to start your
child processes and you have forgotten to use the proper idiom
in the main module:
if __name__ == '__main__':
freeze_support()
...
The "freeze_support()" line can be omitted if the program
is not going to be frozen to produce an executable.
exec(code, run_globals)
any one can help me to solve this problem will be appreciated.