C++ Qt: QProcess run Python script path specifying Python version - python

Qt Creator 4.7.1
Based on Qt 5.11.2 (Clang 8.0 (Apple), 64 bit)
I'm running this in Qt.
QProcess p;
QStringList params;
params << "/Users/johan/Documents/testQt/hello.py";
p.start("python", params);
p.waitForFinished(-1);
qDebug() << "finished";
QString p_stdout = p.readAll();
qDebug() << p_stdout;
QString p_stderr = p.readAllStandardError();
if(!p_stderr.isEmpty())
qDebug()<<"Python error:"<<p_stderr;
I at first had the same error as this: Qt calling python using QProcess
Python error: "ImportError: No module named site\r\n"
And I added:
QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
env.insert("PYTHONPATH", "/Users/johan/anaconda3/lib/python3.7");
env.insert("PYTHONHOME", "/Users/johan/anaconda3/bin/python");
p.setProcessEnvironment(env);
I can directly run the python script from terminal with python hello.py. /Users/johan/anaconda3/bin/python is the output of which python. I suppose I have the correct path for PYTHONHOME, but I'm still getting error.
Python error: " File \"/Users/johan/anaconda3/lib/python3.7/site.py\", line 177\n file=sys.stderr)\n ^\nSyntaxError: invalid syntax\n"
now this is the same error as this: Using multiple versions of Python
But adding what's suggested #!python3 in the script didn't help. I've also tried #!/Users/johan/anaconda3/bin/python.
After searching for hours, now I really don't know how to solve this. How do I specify to run with Python 3? Any help is appreciated.
I guess it's probably still a path problem. Please kindly educate me what I don't understand about PATH in general. I do know PATH is where shell looks for the executable. But why are we inserting PYTHONPATH and PYTHONHOME here instead of just adding it to PATH? What are PYTHONPATH and PYTHONHOME for? (I've read PYTHONHOME documentation but I don't understand.)
EDIT (hello.py for testing package imports):
import time
import sys
import os
import tensorflow as tf
import numpy as np
import time
import inspect
import cv2
def main():
time.sleep(1)
print(os.path)
print(sys.version_info[0])
print("hello")
if __name__ == '__main__':
main()

In PYTHONPATH there must be the paths of the modules(so the minimum is site-packages) so the solution is:
env.insert("PYTHONPATH", "/Users/johan/anaconda3/lib/python3.7/site-packages")
You must also place the path of the python binary that is used:
p.start("/Users/johan/anaconda3/bin/python", params);

Related

Import on shared object fails with ModuleNotFound only when script is executed from command line

ran into a weird problem where there is a shared-object import error only when I run the script from command line. It succeed if i run the script in the python console using exec(...)
I have a class that needs a shared object: foo.py:
import os
cur_dir = os.curdir()
os.chdir('/tmp/dir_with_shared_object/')
import shared_object_class
os.chdir(cur_dir)
class Useful:
... # use the shared object import
Then there is a script like this:
from foo import Useful
If I enter python console and run:
exec(open('script.py').read())
Everything works fine.
If I run this on command line:
python script.py
I will get
ModuleNotFoundError: No module named 'shared_object_class'
The python is the same. It is 3.7.3, GCC 7.3.0 Anaconda. Anyone knows what is causing this discrepancy in behavior for shared object import?
A standard way of importing from a custom directory would be to include it in the PYTHONPATH environmental variable, with export PYTHONPATH=/tmp/dir_with_shared_object/.
update
It could also be done dynamically with
import sys
p = '/tmp/dir_with_shared_object/'
sys.path.insert(0, p)
PS
I think I have an explanation for why OP's original code didn't work. According to this python reference page, the import system searches, inter alia, in "[t]he directory containing the input script (or the current directory when no file is specified)." So the behavior in the REPL loop is different from how it is when running a script. Apparently the current directory is evaluated each time an import statement is encountered, while the directory containing the input script doesn't change.

py2exe executes file but doesn't attempt to build

My question is rather simple: if I try to build my .exe using:
python setup.py py2exe
Python just executes my main file, starting my application, however py2exe doesn't try to build it. Meaning: it does the same as if I'd do:
python setup.py
I guess something is wrong with the distutil?
Anybody already encountered this problem?
py2exe is installed (I reinstalled it, hoping it'd fix it).
My Code:
from testmain import *
from Initfile import *
import math
import py2exe
import matplotlib
import PyQt4
import numpy
from distutils.core import setup
setup(
windows=['Initfile.py'],
data_files=[("GUI", ["testmain.ui"]),*matplotlib.get_py2exe_datafiles()],
options = {
'py2exe': {
'includes' : ['math','py2exe','numpy','matplotlib','PyQt4']
}
}
)
Well the error isn't within distutil, it seems when one imports the entry point itself (in my case Initfile.py) pyexe isnt executing.
So the solution is: remove the line from Initfile import *

Scons fails to import _args_from_interpreter_flags

Im trying to compile Godot engine following the instructions here
When I run scons bin/godot as the tutorial says, I get the following error:
scons: Reading SConscript files ...
ImportError: cannot import name _args_from_interpreter_flags:
File "/home/grayfox/github/godot2/godot/SConstruct", line 9:
import multiprocessing
File "/usr/lib64/python2.7/multiprocessing/__init__.py", line 65:
from multiprocessing.util import SUBDEBUG, SUBWARNING
File "/usr/lib64/python2.7/multiprocessing/util.py", line 40:
from subprocess import _args_from_interpreter_flags
The SConstruct file starts this way:
EnsureSConsVersion(0,14);
import string
import os
import os.path
import glob
import sys
import methods
import multiprocessing
...
If I try to run python SConstruct I get an error complaining about missing functions defined by scons (i.e. the script fails after doing all the imports).
Commenting import multiprocessing fixes the issue but I don't want to modify that file, as I would have to revert the change if I ever make a pull request. The project is quite active so I believe this has something to do with my local configuration.
Any ideas why the script is failing to import _args_from_interpreter_flags only if I execute it via scons?
[UPDATE]
I did a fresh Gentoo install and the problem persists. I did some tests and I found this:
In a python terminal>
>>> import SCons.Script
>>> from subprocess import _args_from_interpreter_flags
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: cannot import name _args_from_interpreter_flags
>>> import subprocess
>>> subprocess.__file__
'/usr/lib64/python2.7/site-packages/SCons/compat/_scons_subprocess.pyc'
But the output is different if I do this:
>>> import subprocess
>>> subprocess.__file__
'/usr/lib64/python2.7/subprocess.pyc'
So I update my question: Is this a bug? Can anybody reproduce it in other distros? If it's a bug, should I report it to Gentoo or to SCons?
[ANOTHER UPDATE]
Adding temp.extend([os.path.join(x, 'lib64') for x in prefs]) did't work, same error.
Adding print sys.path at the beginning of the compact module gives:
['/usr/lib64/python-exec/python2.7/scons-local-2.3.0',
'/usr/lib64/python-exec/python2.7/scons-local',
'/usr/lib64/python2.7/site-packages/lib32/scons-2.3.0',
'/usr/lib32/scons-2.3.0',
'/usr/local/lib32/scons-2.3.0',
'/usr/lib64/python2.7/site-packages/lib/python2.7/site-packages/scons-2.3.0',
'/usr/lib/python2.7/site-packages/scons-2.3.0',
'/usr/local/lib/python2.7/site-packages/scons-2.3.0',
'/usr/lib64/scons-2.3.0',
'/usr/lib64/python2.7/site-packages/lib32/scons',
'/usr/lib32/scons',
'/usr/local/lib32/scons',
'/usr/lib64/python2.7/site-packages/lib/python2.7/site-packages/scons',
'/usr/lib/python2.7/site-packages/scons',
'/usr/local/lib/python2.7/site-packages/scons',
'/usr/lib64/scons',
'/usr/lib64/python2.7/site-packages/RBTools-0.6-py2.7.egg',
'/usr/lib64/python27.zip',
'/usr/lib64/python2.7', #It's here, so what's the problem?
'/usr/lib64/python2.7/plat-linux2',
'/usr/lib64/python2.7/lib-tk',
'/usr/lib64/python2.7/lib-old',
'/usr/lib64/python2.7/lib-dynload',
'/usr/lib64/python2.7/site-packages',
'/usr/lib64/python2.7/site-packages/gtk-2.0',
'/usr/lib64/python2.7/site-packages/wx-2.8-gtk2-unicode']
It looks as if this isn't really a problem connected to SCons directly. You might have an alien "subprocess" module/package installed in your system. Also check out Cannot import name _args_from_interpreter_flags which seems to be related.
Based on your updated question: I tried to compile Godot on my machine (Python 2.7.3, SCons 2.3.1, Ubuntu 12.04 LTS) and it's running fine, so the problem is not related to the provided SConstruct (and its supporting build description files in subfolders). The "_scons_subprocess" module gets used only when the import of the original "subprocess.py" fails. So I suspect that the SCons start script sets up a wrong sys.path, which may happen under 64bit (see issue http://scons.tigris.org/issues/show_bug.cgi?id=2657 ).
After you added "temp.extend([os.path.join(x, 'lib64') for x in prefs])", your "print sys.path" statement shows paths like "/usr/lib64/python-exec" in its output. A Google search turned up the page http://forums.gentoo.org/viewtopic-t-985402-start-0.html for me. It describes an issue with Gentoo, where programs are installed as links to pip. Please follow the given advice and see if this fixes your problem.
It's a bug in Gentoo's scons-2.3.0 and scons-2.3.1 ebuilds (see bug report). It has been fixed in versions 2.3.1-r1 and higher.

Run python script from python using different python

I have a software that has python 2.5.5. I want to send a command that would start a script in python 2.7.5 and then proceed with the script.
I tried using
#!python2.7.5
and http://redsymbol.net/articles/env-and-python-scripts-version/
But I cant get it to work...
In my python 2.5.5 I can execute script as
execfile("c:/script/test.py")
The problem is that the 2.7.5 has a module comtypes + few other. I dont know how to install it for my 2.5.5 so I'm trying to start a separate script and run it under python27. Now another reason why I want it its because I want to take the load off program. I have 2 heavy tasks to perform. The second task is the one that need comptypes so sending it to external shell/app would do perfect trick. Is there a way to do it ?
I wish I could just type run("C:/Python27/python.exe % C:/script/test,py")
Thanks, bye.
Little update. I try to run
import os
os.system("\"C:\Python27\python.exe\" D:\test\runTest.py")
But I'm getting a quick pop up and close window saying that
Import Error : no module named site...
This works if I run from external shell but not from here :(
So I've tried another approach this time to add modules to python... in any case I run this :
import os
import sys
sys.path.append("C:/python27")
sys.path.append("C:/Python27/libs")
sys.path.append("C:/Python27/Lib")
sys.path.append("C:/Python27/Lib/logging")
sys.path.append("C:/Python27/Lib/site-packages")
sys.path.append("C:/Python27/Lib/ctypes")
sys.path.append("C:/Python27/DLLs")
import PyQt4
print PyQt4
import comtypes
import logging
but it crashes with C error...
Runtime Error :
Program: c:\Pr...
R6034
An application has made attempt to load the C runtime library incorectly.
blablabla....
How can I import it ? Maybe if I can import it I can run it directly from my app rather than starting separate python...
Traceback (most recent call last):
File "<string>", line 18, in <module>
File "C:\Python27\Lib\site-packages\comtypes\__init__.py", line 22, in <module>
from ctypes import *
File "C:\Python27\Lib\ctypes\__init__.py", line 10, in <module>
from _ctypes import Union, Structure, Array
ImportError: DLL load failed: A dynamic link library (DLL) initialization routine failed.
Another update to isseu
so I run now
import os
os.system("start cmd {D:\test\runTest.py}")
now this works and he open CMD with c:\Python27 as directory but he dont run the file... any hitns how to fix it?
Use "raw" strings so that you don't need to escape as much; I think the backslashes are what was breaking your code since backslash is considered an escape character except in raw strings.
Also, use the subprocess module. It makes it easy to avoid manually making a safe command string (the module takes care of that for you). All you need to do is pass it a list of arguments.
Your code would then look something like this:
import subprocess
proc = subprocess.Popen([r"C:\Python27\python.exe", r"D:\test\runTest.py"])
# then either do this
proc.wait() # wait until the process finishes
# or this
while True:
# NOTE: do something else here
# poll the process until it is done
if proc.poll() is not None:
break # break out of loop
See subprocess docs for Python 2 here. Be sure to check if a feature was added after Python 2.5 (the 2.5 docs aren't available online anymore AFAIK).
UPDATE:
I just noticed that you tried to use the Python 2.7 libraries and modules in your 2.5 code. This probably won't work due to new features added after 2.5. But it got me thinking how you might be able to make 2.7 work.
It may be that your Python2.7 install can't find its libraries; this is probably why you get the error Import Error : no module named site. You can do something like the above and modify the PYTHONPATH environment variable before starting the subprocess, like this:
import os
import subprocess
paths = [r"C:\python27", r"C:\python27\libs", r"C:\python27\Lib\site-packages", r"C:\python27\DLLs"]
paths += os.environ.get('PYTHONPATH', '').split(os.pathsep)
env27 = dict(os.environ)
env27['PYTHONPATH'] = os.pathsep.join(paths)
proc = subprocess.Popen([r"C:\Python27\python.exe", r"D:\test\runTest.py"], env=env27)

Get external metadata with python script streamripper for win32

Hey I'm using streamripper for win32.
I've setup a sample python script to display dummy metadata.
Streamripper just plain doesn't pick it up. I've put it in the same format as the example:
http://streamripper.sourceforge.net/history.php
It just doesn't work for me.
Anyone know how to fix?
import time
while 1:
print 'TITLE=thisname\nARTIST=thisartist\n.\n'
time.sleep(10)
I put the script in the root directory of streamripper.
Tried linking by using:
script.py
c:/program files/streamripper/script.py
c:\\program files\\streamripper\\script.py
example:
CMD-->
cd c:/program files/streamripper
streamripper http://stream-114.shoutcast.com:80/smoothjazz_skyfm_mp3_96kbps -E script.py
nothing works...
the correct usage is:
streamrippper URL -E python "path to script"
must add python to environment variables of windows
perl conveniently already does on win32 install, but python doesn't
streamripper URL -E perl "path to script"
Also in python, you must flush the output immediately
This works:
import time
import sys
while 1:
print 'TITLE=thetitle\nARTIST=theartistname\n.'
sys.stdout.flush()
time.sleep(10)

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