The problem is that there is an error when the thread transmits data. For example, the following sentence will report an error when it runs
threading.Thread(target=intent, args=([1, 2, 3, 4])).start()
The solution is to add a comma to the last face, as follows
threading.Thread(target=intent, args=([1, 2, 3, 4],)).start()
# or
threading.Thread(target=intent, args=[[1, 2, 3, 4], ]).start()Learning selenium positioning element, the teacher wrote send_ Key (), but I didn’t click in this method. I kept prompting
selenium Python send_ Key error: list object has no attribute
therefore, both methods can be used to solve the problem.
PS: [0] I don’t know what it means. I’ll come back to understand it when I’m in-depth learning
driver = webdriver.Chrome()
driver.get("https://www.baidu.com")
userID = driver.find_elements(By.ID,"kw")[0]
userID.send_keys("123")
driver = webdriver.Chrome()
driver.get("https://www.baidu.com")
driver.find_element(By.ID,"kw").send_keys("456")
Software configuration
Operating system: Ubuntu 16.04
ROS version: kinetic
Python version: python2.7, python3.5, python3.8
Function package and routine
Refer to “ROS robot development and practice” section 4.2.3 using turtle simulator routine turtle_ TF, execute the command:
roslaunch turtle_tf turtle_tf_demo.launch
report errors
Traceback (most recent call last):
File "/opt/ros/kinetic/lib/turtle_tf/turtle_tf_broadcaster.py", line 37, in <module>
import tf
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf/__init__.py", line 28, in <module>
from tf2_ros import TransformException as Exception, ConnectivityException, LookupException, ExtrapolationException
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf2_ros/__init__.py", line 38, in <module>
from tf2_py import *
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf2_py/__init__.py", line 38, in <module>
from ._tf2 import * ImportError: dynamic module does not define module export function (PyInit__tf2) Traceback (most recent call last):
File "/opt/ros/kinetic/lib/turtle_tf/turtle_tf_broadcaster.py", line 37, in <module>
import tf
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf/__init__.py", line 28, in <module>
from tf2_ros import TransformException as Exception, ConnectivityException, LookupException, ExtrapolationException
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf2_ros/__init__.py", line 38, in <module>
from tf2_py import *
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf2_py/__init__.py", line 38, in <module>
from ._tf2 import * ImportError: dynamic module does not define module export function (PyInit__tf2)
Traceback (most recent call last):
File "/opt/ros/kinetic/lib/turtle_tf/turtle_tf_listener.py", line 37, in <module>
import tf
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf/__init__.py", line 28, in <module>
from tf2_ros import TransformException as Exception, ConnectivityException, LookupException, ExtrapolationException
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf2_ros/__init__.py", line 38, in <module>
from tf2_py import *
File "/opt/ros/kinetic/lib/python2.7/dist-packages/tf2_py/__init__.py", line 38, in <module>
from ._tf2 import * ImportError: dynamic module does not define module export function (PyInit__tf2)
find by hard and thorough search
At the beginning, try the methods mentioned on the Internet, such as modifying the python version and soft link, and input on the terminal:
python --version
After getting python2.7, the running routine still reports an error, so I want to find the reason according to the error
↓
Find the error report file from the first line of the error report:
/opt/ros/kinetic/lib/turtle_tf/turtle_tf_broadcaster.py
Turn on Turbo_ tf_ After editing the broadcast.py file, it is found that the first line of the file states:
#!/usr/bin/env python
Input in the terminal:
/usr/bin/env python
It shows the python version pointed by the python variable in the environment variable, which is different from the routine’s requirement of python2.7.
Problem solving: modify Python in environment variables
//Modify the priority of different python versions
sudo update-alternatives --install /usr/bin/python python /usr/bin/python2 100
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 150
//Manual priority selection
sudo update-alternatives --config python
*Remember to input “/ usr/bin/env Python” in the terminal to check whether the modification is successful.
After the modification is successful, run the routine again to see two little turtles. The little turtle at the bottom moves towards the little turtle at the center.
Guided package issues.
How to Solve:
from multiprocessing import Process, Queue
Change to:
from multiprocessing.dummy import Process, Queue
Problem scenario: When executing Python manage.py migrate, an error is reported (1051, “unknown table ‘xxx’), At this time, there is no ‘xxx’ table in the database
Solution:
1. Comment out the tables in models.py that you failed to update
2. Execute after comments are dropped
python manage.py makemigrations python manage.py migrate --fake
3. After the above execution is successful, cancel the table annotation in models.py
4. Cancel the comment and execute
python manage.py makemigrations python manage.py migrate
Collection and solution of error reporting in pyspider
Command “python setup.py egg_ info” failed with error code 10
This means that pycurl installation reported an error
Download address of WHL file of pycurl in win10 solution
# Follow the link above to download the pycurl whl file, pay attention to your own python version, I'm using python 3.7 here
# locate the path to change the file
pip3 install pycurl-7.43.0.4-cp37-cp37m-win_amd64.whl
CentOS solution
yum install python-devel curl-devel
pip3 install pycurl
Ubuntu solution
sudo apt-get install libcurl4-gnutls-dev
pip install pyspider
SyntaxError: invalid syntax
Async cannot be used as a keyword and needs to be changed as a variable
Run pyspider to find the error file and replace async to know that the error was not reported
ImportError: cannot import name ‘Disp
ImportError: cannot import name 'animation' from partially initialized module 'matplotlib' (most likely due to a circular import) (D:\Users\JackYang\anaconda3\lib\site-packages\matplotlib\__init__.py)
The defined file name cannot be the same as the package name. Other names need to be modified.
When jupyter is installed on the vscode and a sentence of Python code is calculated randomly in the ipynb file, the error of kernel died with exit code 1, C:: (users, hpccp, appdata, roaming, python, python38, site packages, traitlets) appears. I’ve been looking for solutions on the Internet all the time. I’ve spent a lot of energy trying many solutions, but I can’t, Because the error of kernel died with exit code 1 may be caused by many different details, and the root cause of the error is different. Of course, other people’s solutions may not be applicable to themselves.
So I began to pay attention to the details of my error. I wonder if there is something wrong with this folder, because my vscode and juptyer plug-ins have just been re installed (I have repeatedly uninstalled and re installed several times, but the first two have not been completely uninstalled), C: The folder was created before. I deleted the folder and its contents. Then the problem was solved.
Execution code:
bro.execute_script('windows.scrollTo(0,document.body.scrollHeight)')
sleep(2)
Implementation results:
selenium.common.exceptions.JavascriptException: Message: javascript error: windows is not defined
(Session info: chrome=91.0.4472.124)
Attention
don’t add s to windows.
pay attention when auto filling!!
Correct writing!!
bro.execute_script('window.scrollTo(0,document.body.scrollHeight)')
sleep(2)
Error:
django.template.exceptions.TemplateSyntaxError: Invalid block tag on line 98: ‘translate’, expected ‘elif’, ‘else’ or ‘endif’. Did you forget to register or load this tag?
Solution:
Find the the catalog in the error message and then delete the red codes.
Save the file and solve it.
There’s something wrong with numpy
Because the latest version of numpy is updated today, the previous usage is invalid
So You need to use the latest usage
Originally, my return value is like this
return np.array(df).astype(np.float)
Error:
DeprecationWarning:
np.floatis a deprecated alias for the builtin
float. To silence this warning, usefloatby itself. Doing this
will not modify any behavior and is safe. If you specifically wanted
the numpy scalar type, usenp.float64here.
Deprecated in NumPy 1.20; for more details and guidance: https://numpy.org/devdocs/release/1.20.0-notes.html#deprecations
return np.array(df).astype(np.float)
It seems to be because of the version of the problem
If you look at the picture
Modify to the following can be.
return np.array(df, dtype=float)
perhaps
return np.array(df).astype(np.float64)
So you won’t make a mistake
This error occurred in Python.
At first, the reason is that I want to change the list with a tensor to a tensor type, that is, [tensor (), tensor ()] to a tensor, and then I write like this,
a = torch.randn(1,2) # tensor([[-0.4962, 0.6034]])
d = [a, a, a] # [tensor([[-0.4962, 0.6034]]), tensor([[-0.4962, 0.6034]]), tensor([[-0.4962, 0.6034]])]
d = torch.tensor(d)It’s a mistake. ValueError: only one element tensors can be converted to Python scalars
I see a solution on the Internet,
val= torch.tensor([item.cpu().detach().numpy() for item in val]).cuda() This method is very unsophisticated and concise.
Another way is to use torch. Cat, which is very concise. If you want to expand dimensions, you can use operations such as unsqueeze on this basis.
d = torch.cat(d, 0)
'''
Output: tensor([[-0.4962, 0.6034],
[-0.4962, 0.6034],
[-0.4962, 0.6034]])
'''