Develop Reference

Launching Spyder yields DLL importing error during `import zmq`

I receive the following error whenever I attempt to launch Spyder:
Traceback (most recent call last):
File "C:\Users\HP\anaconda3\Scripts\spyder-script.py", line 6, in
from spyder.app.start import main
File "C:\Users\HP\anaconda3\lib\site-packages\spyder\app\start.py", line 22, in
import zmq
File "C:\Users\HP\anaconda3\lib\site-packages\zmq\__init__.py", line 47, in
from zmq import backend
File "C:\Users\HP\anaconda3\lib\site-packages\zmq\backend\__init__.py", line 40, in
reraise(*exc_info)
File "C:\Users\HP\anaconda3\lib\site-packages\zmq\utils\sixcerpt.py", line 34, in reraise
raise value
File "C:\Users\HP\anaconda3\lib\site-packages\zmq\backend\__init__.py", line 27, in
_ns = select_backend(first)
File "C:\Users\HP\anaconda3\lib\site-packages\zmq\backend\select.py", line 28, in select_backend
mod = __import__(name, fromlist=public_api)
File "C:\Users\HP\anaconda3\lib\site-packages\zmq\backend\cython\__init__.py", line 6, in
from . import (constants, error, message, context,
ImportError: DLL load failed: The specified module could not be found.
This is an Anaconda 3 installation on Windows. How can I get this to work correctly?

Jupyter Notebook command prompt import error

I'm trying to start up the Jupyter Notebook application and it is not working at all.
I've tried opening it from the windows menu, a command prompt window opens up and closes.
I also tried running it from the anaconda command prompt and it gives me the following error:
(base) C:\Users\GG>jupyter notebook
Traceback (most recent call last):
File "C:\Users\GG\Anaconda3\Scripts\jupyter-notebook-script.py", line 6, in <module>
from notebook.notebookapp import main
File "C:\Users\GG\AppData\Roaming\Python\Python37\site-packages\notebook\notebookapp.py", line 47, in <module>
from zmq.eventloop import ioloop
File "C:\Users\GG\AppData\Roaming\Python\Python37\site-packages\zmq\__init__.py", line 47, in <module>
from zmq import backend
File "C:\Users\GG\AppData\Roaming\Python\Python37\site-packages\zmq\backend\__init__.py", line 40, in <module>
reraise(*exc_info)
File "C:\Users\GG\AppData\Roaming\Python\Python37\site-packages\zmq\utils\sixcerpt.py", line 34, in reraise
raise value
File "C:\Users\GG\AppData\Roaming\Python\Python37\site-packages\zmq\backend\__init__.py", line 27, in <module>
_ns = select_backend(first)
File "C:\Users\GG\AppData\Roaming\Python\Python37\site-packages\zmq\backend\select.py", line 28, in select_backend
mod = __import__(name, fromlist=public_api)
File "C:\Users\GG\AppData\Roaming\Python\Python37\site-packages\zmq\backend\cython\__init__.py", line 6, in <module>
from . import (constants, error, message, context,
ImportError: cannot import name 'constants' from 'zmq.backend.cython' (C:\Users\GG\AppData\Roaming\Python\Python37\site-packages\zmq\backend\cython\__init__.py) ```
Any idea on how to fix this?

Jupyter Lab Not Opening

I am a beginner. Please help. When I pass the jupyter lab command the following error occurs:-
Traceback (most recent call last):
File "c:\users\parijat basak\anaconda3\lib\site-packages\jupyterlab_server\server.py", line 20, in <module>
from notebook.notebookapp import aliases, flags, NotebookApp as ServerApp
File "c:\users\parijat basak\anaconda3\lib\site-packages\notebook\notebookapp.py", line 51, in <module>
from zmq.eventloop import ioloop
File "C:\Users\Parijat Basak\AppData\Roaming\Python\Python38\site-packages\zmq\__init__.py", line 50, in <module>
from zmq import backend
File "C:\Users\Parijat Basak\AppData\Roaming\Python\Python38\site-packages\zmq\backend\__init__.py", line 40, in <module>
reraise(*exc_info)
File "C:\Users\Parijat Basak\AppData\Roaming\Python\Python38\site-packages\zmq\utils\sixcerpt.py", line 34, in reraise
raise value
File "C:\Users\Parijat Basak\AppData\Roaming\Python\Python38\site-packages\zmq\backend\__init__.py", line 27, in <module>
_ns = select_backend(first)
File "C:\Users\Parijat Basak\AppData\Roaming\Python\Python38\site-packages\zmq\backend\select.py", line 28, in select_backend
mod = __import__(name, fromlist=public_api)
File "C:\Users\Parijat Basak\AppData\Roaming\Python\Python38\site-packages\zmq\backend\cython\__init__.py", line 6, in <module>
from . import (constants, error, message, context,
ImportError: cannot import name 'constants' from partially initialized module 'zmq.backend.cython' (most likely due to a circular import) (C:\Users\Parijat Basak\AppData\Roaming\Python\Python38\site-packages\zmq\backend\cython\__init__.py)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "c:\users\parijat basak\anaconda3\lib\runpy.py", line 194, in _run_module_as_main
return _run_code(code, main_globals, None,
File "c:\users\parijat basak\anaconda3\lib\runpy.py", line 87, in _run_code
exec(code, run_globals)
File "C:\Users\Parijat Basak\anaconda3\Scripts\jupyter-lab.EXE\__main__.py", line 4, in <module>
File "c:\users\parijat basak\anaconda3\lib\site-packages\jupyterlab\labapp.py", line 14, in <module>
from jupyterlab_server import slugify, WORKSPACE_EXTENSION
File "c:\users\parijat basak\anaconda3\lib\site-packages\jupyterlab_server\__init__.py", line 4, in <module>
from .app import LabServerApp
File "c:\users\parijat basak\anaconda3\lib\site-packages\jupyterlab_server\app.py", line 9, in <module>
from .server import ServerApp
File "c:\users\parijat basak\anaconda3\lib\site-packages\jupyterlab_server\server.py", line 26, in <module>
from jupyter_server.base.handlers import ( # noqa
ModuleNotFoundError: No module named 'jupyter_server'
Please help!!! I am unable to use Jupyter Lab anymore and it is extremly problematic for me!
Thank You.

From my point of view, it may be faster, and easier is to reinstall Jupyter Lab (maybe create a new conda environment if needed).
One more thing, you might consider backing up your conda environment when everything is smooth:
https://www.anaconda.com/blog/moving-conda-environments

Error when running conda raise ffiplatform.VerificationError(error)

I am working on computer with Ubuntu 16.04.
I have anaconda installed and was using the jupyter notebook just fine both for julia and python a couple of hours while ago. I installed/reinstalled some packages but nothing out of the ordinary.
However, after closing notebooks and then trying to open them again I get error:
jupyter notebook
Traceback (most recent call last):
File "/home/user/anaconda2/bin/jupyter-notebook", line 4, in <module>
import notebook.notebookapp
File "/home/user/anaconda2/lib/python2.7/site-packages/notebook/notebookapp.py", line 60, in <module>
from .services.contents.manager import ContentsManager
File "/home/user/anaconda2/lib/python2.7/site-packages/notebook/services/contents/manager.py", line 16, in <module>
from nbformat import sign, validate, ValidationError
File "/home/user/anaconda2/lib/python2.7/site-packages/nbformat/__init__.py", line 33, in <module>
from .validator import validate, ValidationError
File "/home/user/anaconda2/lib/python2.7/site-packages/nbformat/validator.py", line 12, in <module>
from jsonschema import ValidationError
File "/home/user/anaconda2/lib/python2.7/site-packages/jsonschema/__init__.py", line 18, in <module>
from jsonschema.validators import (
File "/home/user/anaconda2/lib/python2.7/site-packages/jsonschema/validators.py", line 8, in <module>
import requests
File "/home/user/anaconda2/lib/python2.7/site-packages/requests/__init__.py", line 52, in <module>
from .packages.urllib3.contrib import pyopenssl
File "/home/user/anaconda2/lib/python2.7/site-packages/requests/packages/urllib3/contrib/pyopenssl.py", line 46, in <module>
import OpenSSL.SSL
File "/home/user/anaconda2/lib/python2.7/site-packages/OpenSSL/__init__.py", line 8, in <module>
from OpenSSL import rand, crypto, SSL
File "/home/user/anaconda2/lib/python2.7/site-packages/OpenSSL/rand.py", line 11, in <module>
from OpenSSL._util import (
File "/home/user/anaconda2/lib/python2.7/site-packages/OpenSSL/_util.py", line 7, in <module>
binding = Binding()
File "/home/user/anaconda2/lib/python2.7/site-packages/cryptography/hazmat/bindings/openssl/binding.py", line 89, in __init__
self._ensure_ffi_initialized()
File "/home/user/anaconda2/lib/python2.7/site-packages/cryptography/hazmat/bindings/openssl/binding.py", line 109, in _ensure_ffi_initialized
libraries=libraries,
File "/home/user/anaconda2/lib/python2.7/site-packages/cryptography/hazmat/bindings/utils.py", line 80, in build_ffi
extra_link_args=extra_link_args,
File "/home/user/anaconda2/lib/python2.7/site-packages/cffi/api.py", line 437, in verify
lib = self.verifier.load_library()
File "/home/user/anaconda2/lib/python2.7/site-packages/cffi/verifier.py", line 114, in load_library
return self._load_library()
File "/home/user/anaconda2/lib/python2.7/site-packages/cffi/verifier.py", line 225, in _load_library
return self._vengine.load_library()
File "/home/user/anaconda2/lib/python2.7/site-packages/cffi/vengine_cpy.py", line 158, in load_library
raise ffiplatform.VerificationError(error)
cffi.ffiplatform.VerificationError: importing '/home/user/anaconda2/lib/python2.7/site-packages/cryptography/_Cryptography_cffi_4ed9e37dx4000d087.so': /home/user/anaconda2/lib/python2.7/site-packages/cryptography/_Cryptography_cffi_4ed9e37dx4000d087.so: undefined symbol: SSLv2_client_method
I think this has to do with anaconda since the following comands will trigger the same error.
conda install jupyter
pip install jupyter
pip install python-igraph
I have already installed the libraries suggested by the answers to this question (meet cffi.ffiplatform.VerificationError when install pyopenssl). But it hasn't worked.

Neither Anaconda Navigator or Jupyter Notebook will open

I recently installed Anaconda on my Mac (running OS X 10.8.5), and I'm having several errors:
(1) When I try to open the Anaconda Navigator from the anaconda3 folder, the icon displays on my Dock then quickly disappears.
(2) When I use the command anaconda-navigator in terminal, it displays this error message:
Traceback (most recent call last):
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/qtpy/__init__.py", line 166, in <module>
from PySide import __version__ as PYSIDE_VERSION # analysis:ignore
ModuleNotFoundError: No module named 'PySide'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/Users/jakesansom/anaconda3/bin/anaconda-navigator", line 7, in <module>
from anaconda_navigator.app.main import main
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/anaconda_navigator/app/main.py", line 22, in <module>
from anaconda_navigator.utils.conda import is_conda_available
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/anaconda_navigator/utils/__init__.py", line 15, in <module>
from qtpy.QtGui import QIcon
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/qtpy/__init__.py", line 172, in <module>
raise PythonQtError('No Qt bindings could be found')
qtpy.PythonQtError: No Qt bindings could be found
(3) When I use the command jupyter notebook in terminal, it displays this error message:
Traceback (most recent call last):
File "/Users/jakesansom/anaconda3/bin/jupyter-notebook", line 7, in <module>
from notebook.notebookapp import main
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/notebook/notebookapp.py", line 45, in <module>
from zmq.eventloop import ioloop
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/zmq/__init__.py", line 47, in <module>
from zmq import backend
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/zmq/backend/__init__.py", line 40, in <module>
reraise(*exc_info)
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/zmq/utils/sixcerpt.py", line 34, in reraise
raise value
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/zmq/backend/__init__.py", line 27, in <module>
_ns = select_backend(first)
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/zmq/backend/select.py", line 26, in select_backend
mod = __import__(name, fromlist=public_api)
File "/Users/jakesansom/anaconda3/lib/python3.6/site-packages/zmq/backend/cython/__init__.py", line 6, in <module>
from . import (constants, error, message, context,
ImportError: dlopen(/Users/jakesansom/anaconda3/lib/python3.6/site-packages/zmq/backend/cython/error.cpython-36m-darwin.so, 2): Symbol not found: _memset_s
Referenced from: /Users/jakesansom/anaconda3/lib/libsodium.23.dylib
Expected in: /usr/lib/libSystem.B.dylib
in /Users/jakesansom/anaconda3/lib/libsodium.23.dylib
I'm not sure if these issues are related or not, but I decided to post all of them just in case.