Develop Reference

Using dlopen to load one .so in Python says it can't find another in the same directory

I connected yesterday using the SSH protocol to another computer and tried to load, through Python, a SO file (which would be compiled C). Here is what I got in the CLI:
The file that is being requested (libLMR_Demodulator.so) next to "OSError:" is in the same dir as the file I want to load (libDemodulatorJNI_lmr.so).
The python code (v3.5.2) is the following one:
import ctypes
sh_obj = ctypes.cdll.LoadLibrary('./libLMR_Demodulator.so')
actual_start_frequency = sh_obj.getActualStartFrequency(ctypes.c_long(0))
print('The Current Actual Frequency Is: ' + str(actual_start_frequency))

#Charles Duffy is right. The issue come from dependencies. You can verify this by command:
ldd libLMR_Demodulator.so
You have several ways to fix this issue:
Put all the lib to /lib, /usr/lib paths, or directly install them to your system.
Put the libs' path to /etc/ld.so.conf file, then run ldconfig to refresh cache.
use LD_LIBRARY_PATH to add the libs' path, then try to run you script
LD_LIBRARY_PATH=[..path] python [script.py]
or
export LD_LIBRARY_PATH=[..path]
python [script.py]
You can check with manual of dlopen to get more details.

I got here looking for how to ensure that a module / package with a .so file was able to load another .so file that it depends upon -- changing the current directory to the location of the first .so file (i.e., in the directory where the module is) seems to work for me:
import os,sys,inspect
cwd = os.getcwd()
currentdir = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))
os.chdir(currentdir)
import _myotherlib
os.chdir(cwd) # go back
might also work for the OP case?

Python terminal call doesn't load appropriate libraries

I am running a program which utilizes the OpenMPI libraries on Fedora 20.
When I run the command from terminal:
../bin/boxfit ../settings/boxfitsettings.txt | tee boxoutput.log
it is successful.
When I run it through the Python console I return an error:
os.system('../bin/boxfit ../settings/boxfitsettings2.txt | tee boxoutput.log')
../bin/boxfit: error while loading shared libraries: libmpi_cxx.so.1: cannot open shared object file: No such file or directory
The same error results with
subprocess.call(args,shell=True)
I have the paths set the same so it should have access to the same libraries. Is there internal Python functionality that I need to be aware of to get around this error? Or is it perhaps an program compilation error that says the program libraries can't talk to Python?

Looks like it checks for this file in Python's own directory, and not from your current one.
What you could do is for example
path = os.path.abspath("..")
os.system('%s/bin/boxfit %s/settings/boxfitsettings2.txt | tee boxoutput.log' % (path, path))
To get the path of where you are at, then format that into your command

Calling 2to3 in Python using cmd

I have a folder of .py files written in Python 2.7 that I want to convert to Python 3 using the 2to3 tool. Using windows 10 in the cmd prompt i can convert a single file with the following command:
C:\Users\t\Desktop\search>python.exe 2to3.py -w graphicsDisplay.py
however this line is not syntactically correct when in python shell and ideally I'd like to be able to iterate through the whole folder and update all .py files using the by using the following python code in cmd:
C:\Users\t\Desktop\search>python
>>> import os
>>> for files in os.listdir('*filepath*'):
>>> if '.py' == str(files[-3:]):
>>> *...some line of code here to perform 2to3*
its the last line which I can't seem to get right so I guess my question is, how can I call the 2to3 function in python on each iteration of the files variable?

You can do it directly from command line
for %a in (*.py) do python.exe 2to3.py -w "%a"
For each file in the indicated set execute the conversion passing the for replaceable parameter (%a in this sample) that holds the reference to the file being iterated.

Looks like 2to3 support recursive folder checking if you leave out an explicit script to convert.
Would it be easier to have all your scripts in one folder and execute against that instead?
from: https://docs.python.org/2/library/2to3.html#
2to3 --output-dir=python3-version/mycode -W -n python2-version/mycode

Any pyinstaller detailed example about hidden import for psutil?

I want to compile my python code to binary by using pyinstaller, but the hidden import block me. For example, the following code import psutil and print the CPU count:
# example.py
import psutil
print psutil.cpu_count()
And I compile the code:
$ pyinstaller -F example.py --hidden-import=psutil
When I run the output under dist:
ImportError: cannot import name _psutil_linux
Then I tried:
$ pyinstaller -F example.py --hidden-import=_psutil_linux
Still the same error. I have read the pyinstall manual, but I still don't know how to use the hidden import. Is there a detailed example for this? Or at least a example to compile and run my example.py?
ENVs:
OS: Ubuntu 14.04
Python: 2.7.6
pyinstaller: 2.1

Hi hope you're still looking for an answer. Here is how I solved it:
add a file called hook-psutil.py
from PyInstaller.hooks.hookutils import (collect_data_files, collect_submodules)
datas = [('./venv/lib/python2.7/site-packages/psutil/_psutil_linux.so', 'psutil'),
('./venv/lib/python2.7/site-packages/psutil/_psutil_posix.so', 'psutil')]
hiddenimports = collect_submodules('psutil')
And then call pyinstaller --additional-hooks-dir=(the dir contain the above script) script.py

pyinstall is hard to configure, the cx_freeze maybe better, both support windows (you can download the exe directly) and linux. Provide the example.py, In windows, suppose you have install python in the default path (C:\\Python27):
$ python c:\\Python27\\Scripts\\cxfreeze example.py -s --target-dir some_path
the cxfreeze is a python script, you should run it with python, then the build files are under some_path (with a lot of xxx.pyd and xxx.dll).
In Linux, just run:
$ cxfreeze example.py -s --target-dir some_path
and also output a lot of files(xxx.so) under some_path.
The defect of cx_freeze is it would not wrap all libraries to target dir, this means you have to test your build under different environments. If any library missing, just copy them to target dir. A exception case is, for example, if your build your python under Centos 6, but when running under Centos 7, the missing of libc.so.6 will throw, you should compile your python both under Centos 7 and Centos 6.

What worked for me is as follows:
Install python-psutil: sudo apt-get install python-psutil. If you
have a previous installation of the psutil module from other
method, for example through source or easy_install, remove it first.
Run pyinstaller as you do, without the hidden-import option.

still facing the error
Implementation:
1.python program with modules like platform , os , shutil and psutil
when i run the script directly using python its working fine.
2.if i build a binary using pyinstaller. The binary is build successfully. But if i run the binary iam getting the No module named psutil found.I had tried several methods like adding the hidden import and other things. None is working. I trying it almost 2 to 3 days.
Error:
ModuleNotFoundError: No module named 'psutil'
Command used for the creating binary
pyinstaller --hidden-import=['_psutil_linux'] --onefile --clean serverHW.py
i tried --additional-hooks-dir= also not working. When i run the binary im getting module not found error.

How to use docutils to convert .rsts to htmls?

I downloaded a util(cmake,actually) tar,and it's doc was written as .rst files with structure like blow.After googling,I know docutils(a python package) can convert these files to htmls,so installed it ,but I can't find a way to to do it?please tell me,is there any simple command to do it?How?
//doc files structure(generated by ls -l under ubuntu)
command
generator
include
index.rst
manual
module
policy
prop_cache
prop_dir
prop_gbl
prop_sf
prop_test
prop_tgt
release
variable

The docutils documentation tells you what to do. In your case, you want the rst2html.py command, which should have been installed in your PATH when you installed the module. Run
rst2html.py --help
to see what the command-line options are.