I am working with executable files that are to be included in the main node file. But the problem is that although I can define the path in my PC and open a text file with or execute the file but it is not universal with my other team members which are part of the team. The have to change the code after pulling from git.
I have the following commands:
os.chdir( "/home/user/epsilon/epsilon_catkin_ws/src/knowledge_source/sense_manager/pddl_files/")
os.system("./ff -p /home/user/epsilon/epsilon_catkin_ws/src/knowledge_source/sense_manager/pddl_files/ -o domain.pddl -f problem.pddl >
solution_path = "/home/user/epsilon/epsilon_catkin_ws/src/knowledge_source/sense_manager/pddl_files/solution.txt" solution_detail.txt")
Since the path are unique with my laptop, it will require changes by everyone. IS there a way to make the path definition universal? (The commands are part of the service call that is present in that node). I am using rosrun to run the node
I tried the following pattern but it does not work:
os.chdir( "$(find knowledge_source)/sense_manager/pddl_files/")
Do I need to do something extra to make this work?
knowledge_source is the name of the package
Any recommendations?
I think you are looking for rospkg and os combination to get the path to a file inside a ros package.
import rospkg
import os
conf_file_path = os.path.join(rospkg.RosPack().get_path('your_ros_pkg'), 'your_folder_in_the_package', 'your_file_name')
Related
I have a python file that I tested locally using VS-Code and the shell. The file contains relative imports and worked as intended on my local machine.
After uploading the associated files to Colab I did the following:
py_file_location = '/content/gdrive/content/etc'
os.chdir(py_file_location)
# to verify whether I got the correct path
!python3
>>> import os
>>> os.getcwd()
output: '/content/gdrive/MyDrive/content/etc'
However, when I run the file I get the following error:
ImportError: attempted relative import with no known parent package
Why is that? Using the same file system and similar shell commands the file worked locally.
A solution that worked for me was to turn my relative paths into static ones, so instead of using:
directory = pathlib.Path(__file__).parent
sys.path.append(str(directory.parent))
sys.path.append(str(directory.parent.parent.parent))
__package__ = directory.name
I needed to make the path static by using resolve():
directory = pathlib.Path(__file__).resolve().parent
sys.path.append(str(directory.parent))
sys.path.append(str(directory.parent.parent.parent))
__package__ = directory.name
It is however still not fully clear to me why this is required when running on Colab but not when running locally.
I just try to create some new folders with Python's (3.7.3) os.makedirs() and os mkdir().
Apparently, it works fine because no error occurs (Win 10 Home). But as I try to find the created folder in the windows explorer it isn't there.
Trying to create it again with python I get an error:
'[WinError 183] Cannot create a file when that file already exists:'
Strange thing is, all this worked fine on my computer at work (Wind 10 too), and also on my android tablet.
I've already tried to use relative & absolute paths in makedirs / mkdir.
Ok, it's all about these few lines:
import os
# print(os.getcwd()) shows: C:\Users\Andrej\Desktop
# tried relative path..
os.makedirs('Level1/Level2/Level3')
# tried out some absolute paths like...
os.makedirs('C:/Users/Andrej/Desktop/Level1/Level2/Level3')
os.makedirs('C:\\Users\\Andrej\\Desktop\\Level1\\Level2\\Level3')
UPDATE: It works perfectly when I write makedirs command directly in the Windows powershell. The issue above only occurs when I write this code in Visual Code Studio and then start the file from the powershell by typing in: python makedirs.py...
I just had the same thing happen to me, except I was creating a folder in the AppData/Roaming directory and was using the version of Python from the Microsoft Store.
Apparently, files and directories created in AppData using that version of Python, will instead be created in:
%LocalAppData%\Packages\PythonSoftwareFoundation.Python.3.8_qbz5n2kfra8p0\LocalCache
I found what causes this problem finally!
All of the created test folders have been moved to a folder named VTROOT. This folder is created by Comodo Internet Security I use...Its "Auto-Containment" moved all folders I set up by running the code from .py-file (only then) in the PowerShell.
Disabling the auto-containment of Comodo solves the problem..Oh my..
Thank you anyways!
the "if" part will check if the file exists already and consequentially solve the ERROR: '[WinError 183] Cannot create a file when that file already exists:'
the "import sys" part will fix the issue with windows where the folder is created but not visible by the user (even with show hidden files turned on)
import sys
import os
path = 'your path'
def make_dir():
if not os.path.exists(Path):
os.makedirs(Path)
or
import sys
import os
path = 'your path'
def make_dir():
mode = 0o666 #read and write for all users and groups
# form more permission codes search for: *chmod number codes*
if not os.path.exists(Path):
os.mkdir(Path, mode)
Try adding the below import statement:
import sys
This should work.
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?
I am trying to run this tool within a lambda function: https://github.com/nicolas-f/7DTD-leaflet
The tool depends on Pillow which depends on imaging libraries not available in the AWS lambda container. To try and get round this I've ran pyinstaller to create a binary that I can hopefully execute. This file is named map_reader and sits at the top level of the lambda zip package.
Below is the code I am using to try and run the tool:
command = 'chmod 755 map_reader'
args = shlex.split(command)
print subprocess.Popen(args)
command = './map_reader -g "{}" -t "{}"'.format('/tmp/mapFiles', '/tmp/tiles')
args = shlex.split(command)
print subprocess.Popen(args)
And here is the error, which occurs on the second subprocess.Popen call:
<subprocess.Popen object at 0x7f08fa100d10>
[Errno 13] Permission denied: OSError
How can I run this correctly?
You may have been misled into what the issue actually is.
I don't think that the first Popen ran successfully. I think that it just dumped a message in standard error and you're not seeing it. It's probably saying that
chmod: map_reader: No such file or directory
I suggest you can try either of these 2:
Extract the map_reader from the package into /tmp. Then reference it with /tmp/map_reader.
Do it as recommended by Tim Wagner, General Manager of AWS Lambda who said the following in the article Running Arbitrary Executables in AWS Lambda:
Including your own executables is easy; just package them in the ZIP file you upload, and then reference them (including the relative path within the ZIP file you created) when you call them from Node.js or from other processes that you’ve previously started. Ensure that you include the following at the start of your function code:
process.env[‘PATH’] = process.env[‘PATH’] + ‘:’ + process.env[‘LAMBDA_TASK_ROOT’]
The above code is for Node JS but for Python, it's like the following
import os
os.environ['PATH']
That should make the command command = './map_reader <arguments> work.
If they still don't work, you may also consider running chmod 755 map_reader before creating the package and uploading it (as suggested in this other question).
I know I'm a bit late for this but if you want a more generic way of doing this (for instance if you have a lot of binaries and might not use them all), this how I do it, provided you put all your binaries in a bin folder next to your py file, and all the libraries in a lib folder :
import shutil
import time
import os
import subprocess
LAMBDA_TASK_ROOT = os.environ.get('LAMBDA_TASK_ROOT', os.path.dirname(os.path.abspath(__file__)))
CURR_BIN_DIR = os.path.join(LAMBDA_TASK_ROOT, 'bin')
LIB_DIR = os.path.join(LAMBDA_TASK_ROOT, 'lib')
### In order to get permissions right, we have to copy them to /tmp
BIN_DIR = '/tmp/bin'
# This is necessary as we don't have permissions in /var/tasks/bin where the lambda function is running
def _init_bin(executable_name):
start = time.clock()
if not os.path.exists(BIN_DIR):
print("Creating bin folder")
os.makedirs(BIN_DIR)
print("Copying binaries for "+executable_name+" in /tmp/bin")
currfile = os.path.join(CURR_BIN_DIR, executable_name)
newfile = os.path.join(BIN_DIR, executable_name)
shutil.copy2(currfile, newfile)
print("Giving new binaries permissions for lambda")
os.chmod(newfile, 0775)
elapsed = (time.clock() - start)
print(executable_name+" ready in "+str(elapsed)+'s.')
# then if you're going to call a binary in a cmd, for instance pdftotext :
_init_bin('pdftotext')
cmdline = [os.path.join(BIN_DIR, 'pdftotext'), '-nopgbrk', '/tmp/test.pdf']
subprocess.check_call(cmdline, shell=False, stderr=subprocess.STDOUT)
There were two issues here. First, as per Jeshan's answer, I had to move the binary to /tmp before I could properly access it.
The other issue was that I'd ran pyinstaller on ubuntu, creating a single file. I saw elsewhere some comments about being sure to compile on the same architecture as the lambda container runs. Therefore I ran pyinstaller on ec2 based on the Amazon Linux AMI. The output was multiple .os files, which when moved to tmp, worked as expected.
copyfile('/var/task/yourbinary', '/tmp/yourbinary')
os.chmod('/tmp/yourbinary', 0555)
Moving the binary to /tmp and making it executable worked for me
There is no need to copy the files the /tmp. You can just use ld-linux to execute any file including those not marked executable.
So, for running a non-executable on AWS Lambda, you use the following command:
/lib64/ld-linux-x86-64.so.2 /opt/map_reader
P.S. It would make more sense to add the map_reader binary or any other static files in a Lambda Layer, thus the /opt folder.
Like the docs mention for Node.js, you need to update the $PATH, else you'll get command not found when trying to run the executables you added at the root of your Lambda package. In Node.js, that's:
process.env['PATH'] = process.env['PATH'] + ':' + process.env['LAMBDA_TASK_ROOT']
Now, the same thing in Python:
import os
# Make the path stored in $LAMBDA_TASK_ROOT available to $PATH, so that we
# can run the executables we added at the root of our package.
os.environ["PATH"] += os.pathsep + os.environ['LAMBDA_TASK_ROOT']
Tested OK with Python 3.8.
(As a bonus, here are some more env variables used by Lambda.)
I'm running the following MapReduce on AWS Elastic MapReduce:
./elastic-mapreduce --create --stream --name CLI_FLOW_LARGE --mapper
s3://classify.mysite.com/mapper.py --reducer
s3://classify.mysite.com/reducer.py --input
s3n://classify.mysite.com/s3_list.txt --output
s3://classify.mysite.com/dat_output4/ --cache
s3n://classify.mysite.com/classifier.py#classifier.py --cache-archive
s3n://classify.mysite.com/policies.tar.gz#policies --bootstrap-action
s3://classify.mysite.com/bootstrap.sh --enable-debugging
--master-instance-type m1.large --slave-instance-type m1.large --instance-type m1.large
For some reason the cacheFile classifier.py is not being cached, it would seem. I get this error when the reducer.py tries to import it:
File "/mnt/var/lib/hadoop/mapred/taskTracker/hadoop/jobcache/job_201204290242_0001/attempt_201204290242_0001_r_000000_0/work/./reducer.py", line 12, in <module>
from classifier import text_from_html, train_classifiers
ImportError: No module named classifier
classifier.py is most definitely present at s3n://classify.mysite.com/classifier.py. For what it's worth, the policies archive seems to load in just fine.
I don't know how to fix this problem in EC2, but I've seen it before with Python in traditional Hadoop deployments. Hopefully the lesson translates over.
What we need to do is add the directory reduce.py is in to the python path, because presumably classifier.py is in there too. For whatever reason, this place is not in the python path, so it is failing to find classifier.
import sys
import os.path
# add the directory where reducer.py is to the python path
sys.path.append(os.path.dirname(__file__))
# __file__ is the location of reduce.py, along with "reduce.py"
# dirname strips the file name and only gives the directory
# sys.path is the python path where it looks for modules
from classifier import text_from_html, train_classifiers
The reason why your code might work locally is because of the current working directory in which you are running it from. Hadoop might not be running it from the same place you are in terms of the current working directory.
orangeoctopus deserves credit for this from his comment. Had to append the working directory system path:
sys.path.append('./')
Also, I recommend anyone who has similar issues to me to read this great article on using Distributed Cache on AWS:
https://forums.aws.amazon.com/message.jspa?messageID=152538