I am using ROS-melodic with the following environment variables:
ROS_PYTHON_VERSION=2
ROS_PACKAGE_PATH=/home/florian/git/software_integration/src:/opt/ros/melodic/share
For a project I want to get a obstacle detection and implement trajectory prediction using a LIDAR sensor. To achieve this, I installed the following github repo according to the given instructions:
https://github.com/kostaskonkk/datmo
The repo works so far, I can start the examples and the topics are published. Now I want to implement a new listener, with the following MWE:
#!/usr/bin/env python
import rospy
from datmo.msg import TrackArray
def callbackTrackArray(data):
print(type(data.date))
def getInput():
rospy.init_node('obstacleComputer', anonymous= True)
tracks = rospy.Subscriber("datmo/box_kf", TrackArray, callbackTrackArray)
rospy.spin()
if __name__ == '__main__':
getInput()
But if I run it, it yells "No module named 'datmo'". But PyCharm even suggests me "datmo" if I type "import da", so he knows it.
I am using a Python 3.8 venv in PyCharm with the following Interpreter Paths:
Also, my project structure looks like this (and there the datmo package is located):
Full Error Stack:
Traceback (most recent call last):
File "/home/florian/git/software_integration/src/trajectory_prediction/src/ObstacleComputer.py", line 7, in <module>
from datmo.msg import TrackArray
ModuleNotFoundError: No module named 'datmo'
I had to add the ROS_PACKAGE_PATH to the interpreter settings --> environment variables
Related
protoc was generating invalid code in Python 3.8. I found that it works in Python 3.6.
I followed the instructions as per: This fantastic blog
The command I ran was:
python -m grpc_tools.protoc --python_out=src/ --grpc_python_out=src/ --proto_path generated=./src/interfaces src/interfaces/ecg.proto
The first issue was the generated imports were not working. I changed the code as below, for the import to work, in pb2_grpc.py:
from . import ecg_pb2 as generated_dot_ecg__pb2
The imports were fine in Visual Code, but now the run-time error.
I have a couple of files in the "generated" folder. I also added an init.py into this folder that was supposed to expose the contents, as:
from .ecg_pb2 import *
from .ecg_pb2_grpc import *
At a peer level to this "generated" folder I have another file - server.py. I am trying to import "generated". It is only importing with a relative path: from .generated import ecg_pb2_grpc
However, while the import works with the relative path, the main in server.py is not getting invoked. Run time error -
(p36) C:\ECG\src>python ecg_server.py
Traceback (most recent call last):
File "ecg_server.py", line 6, in
from .generated import ecg_pb2
ModuleNotFoundError: No module named 'main.generated'; 'main' is not a package
I have a folder structure like this:
C:
|_Blueprint
│ main.py
│
└───toolbox
blueprint_tools.py
When I run this code in Blender's scripting text page:
from toolbox.blueprint_tools import dimension, array, modify
I get an error in the console
Traceback (most recent call last):
File "\main.py", line 20, in <module>
ModuleNotFoundError: No module named 'toolbox'
Error: Python script failed, check the message in the system console
I swear, when I run this code (on other projects) outside of Blender this structure and code runs fine. But I get an error when running this script in Blender for testing out my Add-On.
If I compile the Blueprint folder into a .zip and install it everything works fine.... ??
I'm lost, could anyone please help me.
If I run the code like this: (added a . before toolbox for CWD)
from .toolbox.blueprint_tools import dimension, array, modify
Traceback (most recent call last):
File "\main.py", line 20, in <module>
ImportError: attempted relative import with no known parent package
Error: Python script failed, check the message in the system console
Both your error traces write File \main.py ... which means that Blender considers your main.py file to be in the root folder, knowing nothing about its real location in the file system hierarchy.
When you installed your structure as a zip file, you provided all necessary info to Blender.
Addendum:
Temporarily, during developing / debugging your add-on, you may add the full path (for finding your toolbox.blueprint_tools module) to the sys.path variable.
There are 2 possibilities how to do it:
Insert into your main.py file these commands (use the path to your parent folder of your toolbox folder, of course):
import sys
sys.path += [r"C:\Users\Davi\Documents\Python\PARENT_of_toolbox"]
before your statement
from toolbox.blueprint_tools import dimension, array, modify
command, or
Insert into your main.py file these commands (use the path to your toolbox folder, of course):
import sys
sys.path += [r"C:\Users\Davi\Documents\Python\PARENT_of_toolbox\toolbox"]
before your modified statement
from blueprint_tools import dimension, array, modify
I have a test that passes with pytest. I also have an adjacent source that's a console app (not pytest) that exercises the same function that barfs with ModuleNotFoundError for the same function call.
mylib/mylib.py:
def adder(num1, num2):
return num1 + num2
test/my_test.py:
from mylib.mylib import adder
def test_adder():
assert adder(2, 2) == 4
test/mytest_outside_pytest.py:
from mylib.mylib import adder
print(str(adder(2, 2)))
As I suggest pytest completes and indicates the test passed, but the following does not:
$ python3 test/mytest_outside_pytest.py
Traceback (most recent call last):
File "test/mytest_outside_pytest.py", line 1, in <module>
from mylib.mylib import adder
ModuleNotFoundError: No module named 'mylib'
Nor does:
$ cd test/
$ python3 mytest_outside_pytest.py
Traceback (most recent call last):
File "mytest_outside_pytest.py", line 1, in <module>
from mylib.mylib import adder
ModuleNotFoundError: No module named 'mylib'
I have empty __init__.py in both folders. I don't know what pytest does to path loading that I can't replicate in my "main" console app. Of course I don't really care about an adder lib, I'm just aiming at the smallest reproducible problem.
pytest has a quite complex mechanism to add some directories to the PYTHONPATH and allow tests to run automagically (see the doc)
When you do not use pytest you do not have this mechanism and you have to manage the PYTHONPATH by yourself.
Why the PYTHONPATH is not correct in your case?
When you run a module using python path/to/module.py, the interpreter adds the directory containing the module (absolute path of path/to in this example) in the PYTHONPATH.
In your case, you run python test/mytest_outside_pytest.pyand the interpreter adds the absolute path of test directory in the PYTHONPATH.
You can check it by adding import pdb; pdb.set_trace() at the very beginning of your mytest_outside_pytest.py module to enter a debug session and run it. Then import sys and display the sys.path to see that test is the first directory in your PYTHONPATH.
You can also see that the root directory is not listed and thus the packages it contains cannot be imported.
How to solve it?
It can be done in multiple ways.
You can manually define the PYTHONPATH in your command:
PYTHONPATH=. python test/mytest_outside_pytest.py
or you can use python -m ... as suggested in comment (do not forget that in this case, you have to specify a module, not a path, and remember that it will work only from the directory containng the mylib and test packages):
python -m test.mytest_outside_pytest
In both cases, a debug session can show you that the root directory and the test directory are in the PYTHONPATH
I have a project structured this way...
main.py imports scripts from subfolders like so:
from controllers.available_balances_controller import available_balances_controller
Subfolders:
models
views
controllers
When running main.py in Pycharm it works find.
When I try to run in terminal I get import errors:
Traceback (most recent call last):
File "main.py", line 6, in <module>
from controllers.available_balances_controller import available_balances_controller
ImportError: No module named controllers.available_balances_controller
Am I importing the scripts wrong in main.py?
What is the proper way to do the importing?
Try running your script with the -m flag:
$ python -m main
That means that you are running your main.py as a module inside a python package, not as a simple script. PyCharm makes it easy for you by assuming so when you create a project. When you are in the terminal, you need to specify it yourself. You don't need __init__.py files inside your directories in Python3.
Check out:
https://docs.python.org/3/reference/import.html
Relative imports in Python 3
I want to try Mako with Django instead of Django's default template language. But I'm having a problem when I try to import Mako's Template class as written in the manual:
from mako.template import Template
mytemplate = Template("hello world!")
print mytemplate.render()
I do this in Windows cmd and receive such an error:
C:\Documents and Settings\User>cd C:\py\project\vendor\template\Mako_73 // cd to where I unpacked Mako
C:\py\project\vendor\template\Mako_73>python // run Python interpreter
>>> from mako.template import Template // trying to import and getting an error
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File ".\mako\template.py", line 622
exec code in module.__dict__, module.__dict__
^
SyntaxError: invalid syntax
The code from that part:
def _compile_text(template, text, filename):
identifier = template.module_id
source, lexer = _compile(template, text, filename,
generate_magic_comment=template.disable_unicode)
cid = identifier
if not util.py3k and isinstance(cid, unicode):
cid = cid.encode()
module = types.ModuleType(cid)
code = compile(source, cid, 'exec')
exec code in module.__dict__, module.__dict__
return (source, module)
What can it be? I couldn't find anything in Google about this error.
I'm using Python 3.3.
I've downloaded Mako-0.7.3 as tar.gz file and just unzipped it in
C:\py\poject\vendor\template\Mako_73. I do not have this directory in the PYTHONPATH or paths.pth. C:\py\poject is a directory where my Django project lives and in \vendor\template I've decided to put Mako and import it from there.
UPD
I found the solution. I've installed the Pyramid Framework and have taken the Mako from there as the Mako is a default template system in it. And Pyramid's version works fine.
Your basic problem is that you are using Python 3, which is relatively new for large projects like Django.
Secondly, you need to find out how to install packages correctly. I don't know where you got Mako from, but you won't find anywhere that says "just unpack the tarball" - perhaps you are assuming that from your knowledge of PHP, but it's not correct.
On the Mako site, the suggested method of installation is pip.
If you go for downloading manually, you need to read instructions about installing Python packages, for example here: http://wiki.python.org/moin/CheeseShopTutorial
The reason Mako doesn't work for you is that the installation procedure (which you haven't run) converts all the provided Python 2 code so that it works on Python 3. It is not that someone didn't bother to check the code for basic syntax errors!
If you are trying to use Django, though, Python 3 is definitely the wrong choice - the installation instructions clearly say you need to be using Python 2.5 to 2.7: https://docs.djangoproject.com/en/1.4/intro/install/
Since you are new to Python, you should try to walk before you run, and go with the tried and tested path - which is Python 2.7 for Django. Ignoring installation instructions and requirements will only slow you down and make life hard.