No module named _backend_gdk - python

I am using Spyder with python 2.7 and matplotlib on a windows machine.
I am trying to run my script and I am getting the following error:
runfile('C:/Python27/Scripts/python-serial-plot.py', wdir=r'C:/Python27/Scripts')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python27\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 601, in runfile
execfile(filename, namespace)
File "C:\Python27\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 66, in execfile
exec(compile(scripttext, filename, 'exec'), glob, loc)
File "C:/Python27/Scripts/python-serial-plot.py", line 8, in <module>
from matplotlib.backends.backend_gtkagg import FigureCanvasGTKAgg as FigureCanvas
File "C:\Python27\lib\site-packages\matplotlib\backends\backend_gtkagg.py", line 14, in <module>
from matplotlib.backends.backend_gtk import gtk, FigureManagerGTK, FigureCanvasGTK,\
File "C:\Python27\lib\site-packages\matplotlib\backends\backend_gtk.py", line 36, in <module>
from matplotlib.backends.backend_gdk import RendererGDK, FigureCanvasGDK
File "C:\Python27\lib\site-packages\matplotlib\backends\backend_gdk.py", line 33, in <module>
from matplotlib.backends._backend_gdk import pixbuf_get_pixels_array
ImportError: No module named _backend_gdk
I went to the directory where the backends are stored and can't see _backend_gdk.
How can I fix this issue?

You need to change your graphics backend to fix this error. In Spyder you need to go to
Tools > Preferences > IPython console > Graphics > Graphics backend
and select there either Inline or Automatic there.

You can switch the backend to list all backends:
In [5]: import matplotlib
In [6]: matplotlib.rcsetup.all_backends
Then use matplotlib.use('some_backend') to choose another, I don't use windows so cannot recommend what to use but you can try different ones and see what works best.
The matplotlib.use('some_backend') should be before any import matplotlib.pyplot etc.. statements
what is a backend

Related

Failed to import any qt binding - Spyder on Windows 10

I'm trying to animate a trajectory of an object in 2D using python.
The problem is, when i try to do so I get this famous error
Traceback (most recent call last):
File "C:\Users\Pierre\OneDrive\Documents\Etudes\Master\M2\Stage\tests\sympy and gekko.py", line 13, in <module>
import matplotlib.pyplot as plt
File "C:\Python39\lib\site-packages\matplotlib\pyplot.py", line 2336, in <module>
switch_backend(rcParams["backend"])
File "C:\Python39\lib\site-packages\matplotlib\pyplot.py", line 276, in switch_backend
class backend_mod(matplotlib.backend_bases._Backend):
File "C:\Python39\lib\site-packages\matplotlib\pyplot.py", line 277, in backend_mod
locals().update(vars(importlib.import_module(backend_name)))
File "C:\Python39\lib\importlib\__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "C:\Python39\lib\site-packages\matplotlib\backends\backend_qt5agg.py", line 11, in <module>
from .backend_qt5 import (
File "C:\Python39\lib\site-packages\matplotlib\backends\backend_qt5.py", line 16, in <module>
import matplotlib.backends.qt_editor.figureoptions as figureoptions
File "C:\Python39\lib\site-packages\matplotlib\backends\qt_editor\figureoptions.py", line 11, in <module>
from matplotlib.backends.qt_compat import QtGui
File "C:\Python39\lib\site-packages\matplotlib\backends\qt_compat.py", line 177, in <module>
raise ImportError("Failed to import any qt binding")
ImportError: Failed to import any qt binding
I tried every solution I found (installing PyQt5 and importing it, reinstalling matplotlib, updating pip) and nothing works. I still get the same error every time.
I'm on windows 10 and I installed python (3.9.2) using chocolatey. I'm coding with spyder 4.2.2
I've seen someone speaking about how updating his GPU driver helped but mine is up to date and still nothing (Radeon RX580).
Does anybody have a clue on what could be the issue ?
Installing Pyside2 did the trick. No need to for the import PyQt5 if you have the option picked in the preferences of Spyder

cvxpy import error : cannot read file data

I'm trying to use cvxpy on a pythonanywhere server, the installation was ok, no errors however when i want to import cvpxy as cp, i have an error, help me please
the error :
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/cvxpy/__init__.py", line 18, in <module>
from cvxpy.atoms import *
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/cvxpy/atoms/__init__.py", line 17, in <module>
from cvxpy.atoms.cummax import cummax
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/cvxpy/atoms/cummax.py", line 17, in <module>
from cvxpy.atoms.atom import Atom
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/cvxpy/atoms/atom.py", line 21, in <module>
from cvxpy.expressions.constants import Constant
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/cvxpy/expressions/constants/__init__.py", line 17, in <module>
from .constant import Constant
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/cvxpy/expressions/constants/constant.py", line 22, in <module>
from scipy.sparse.linalg import eigsh
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/scipy/sparse/linalg/__init__.py", line 111, in <module>
from .isolve import *
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/scipy/sparse/linalg/isolve/__init__.py", line 4, in <module>
from .iterative import *
File "/home/padacore/.virtualenvs/env/lib/python3.7/site-packages/scipy/sparse/linalg/isolve/iterative.py", line 8, in <module>
from . import _iterative
ImportError: /home/padacore/.virtualenvs/env/lib/python3.7/site-packages/scipy/sparse/linalg/isolve/../../../../scipy.libs/libopenblasp-r0-085ca80a.3.9.so: cannot read file data
It could be something to do with Atom, try switching to another editor. I recommend PyCharm or VSCode. If you're choosing VSCode, install these extensions: Python, PyLance, and Jupyter.
If you don't like VSCode's default themes, and miss Atom's One Dark, then there's an extension just for that! Just search for it, and you'll find it!
EDIT: If it wasn't something to do with Atom, maybe install an older version of cvxpy

Anaconda/Conda on OS X 11 -- Broken Jupyter Notebook with DEFAULT installation

I am running the latest Anaconda on OS X 11 and cannot for the life of me figure out how to get jupyter notebook to run. It ends in this error:
% jupyter notebook
Traceback (most recent call last):
File "/usr/local/opt/anaconda3/bin/jupyter-notebook", line 7, in <module>
from notebook.notebookapp import main
File "/usr/local/opt/anaconda3/lib/python3.7/site-packages/notebook/notebookapp.py", line 85, in <module>
from .services.contents.manager import ContentsManager
File "/usr/local/opt/anaconda3/lib/python3.7/site-packages/notebook/services/contents/manager.py", line 17, in <module>
from nbformat import sign, validate as validate_nb, ValidationError
File "/usr/local/opt/anaconda3/lib/python3.7/site-packages/nbformat/__init__.py", line 32, in <module>
from .validator import validate, ValidationError
File "/usr/local/opt/anaconda3/lib/python3.7/site-packages/nbformat/validator.py", line 12, in <module>
from .json_compat import get_current_validator, ValidationError
File "/usr/local/opt/anaconda3/lib/python3.7/site-packages/nbformat/json_compat.py", line 10, in <module>
import jsonschema
File "/usr/local/opt/anaconda3/lib/python3.7/site-packages/jsonschema/__init__.py", line 32, in <module>
from pkg_resources import get_distribution
ModuleNotFoundError: No module named 'pkg_resources'
I have tried fresh installs of both miniconda and anaconda without success. Nothing seems to work.
It baffles me that a default install of anaconda (no updates, no extra packages, nothing) is broken. Do these people even test their stuff?
Any solutions or suggestions? Thanks in advance!

Python 2.7: Unable to import matplotlib.pyplot

When I tried to
import matplotlib.pyplot as plt
I was given the following error:
runfile('/Users/Zhengnan/Documents/Python/PS 2/230I_PS_2.py', wdir='/Users/Zhengnan/Documents/Python/PS 2')
Traceback (most recent call last):
File "<ipython-input-2-9001323bba15>", line 1, in <module>
runfile('/Users/Zhengnan/Documents/Python/PS 2/230I_PS_2.py', wdir='/Users/Zhengnan/Documents/Python/PS 2')
File "/Users/Zhengnan/anaconda/lib/python2.7/site-packages/spyderlib/widgets/externalshell/sitecustomize.py", line 685, in runfile
execfile(filename, namespace)
File "/Users/Zhengnan/anaconda/lib/python2.7/site-packages/spyderlib/widgets/externalshell/sitecustomize.py", line 78, in execfile
builtins.execfile(filename, *where)
File "/Users/Zhengnan/Documents/Python/PS 2/230I_PS_2.py", line 4, in <module>
import matplotlib.pyplot as plt
File "/Users/Zhengnan/anaconda/lib/python2.7/site-packages/matplotlib/pyplot.py", line 27, in <module>
import matplotlib.colorbar
File "/Users/Zhengnan/anaconda/lib/python2.7/site-packages/matplotlib/colorbar.py", line 34, in <module>
import matplotlib.collections as collections
File "/Users/Zhengnan/anaconda/lib/python2.7/site-packages/matplotlib/collections.py", line 27, in <module>
import matplotlib.backend_bases as backend_bases
File "/Users/Zhengnan/anaconda/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 56, in <module>
import matplotlib.textpath as textpath
File "/Users/Zhengnan/anaconda/lib/python2.7/site-packages/matplotlib/textpath.py", line 22, in <module>
from matplotlib.mathtext import MathTextParser
File "/Users/Zhengnan/anaconda/lib/python2.7/site-packages/matplotlib/mathtext.py", line 63, in <module>
import matplotlib._png as _png
ImportError: dlopen(/Users/Zhengnan/anaconda/lib/python2.7/site-packages/matplotlib/_png.so, 2): Library not loaded: #loader_path/../../../libpng15.15.dylib
Referenced from: /Users/Zhengnan/anaconda/lib/python2.7/site-packages/matplotlib/_png.so
Reason: image not found
Can anyone please help me? I'm a newbie and not really familiar with paths. A step-by-step instruction would be greatly appreciated. Thanks in advance.
BTW, I'm using spyder as an IDE.
as presented here:
https://askubuntu.com/questions/636937/python-2-7-matplotlib-provides-errorpyplot
this command will fix it:
conda install matplotlib
and indeed it helped me.
I use Kali Linux,I use:
pip install matplotlib
It's likely your library path is not set up correctly, and doesn't point to wherever the file libpng15.15.dylib is located.
Since this file should probably come with the anaconda installation (provided this is how you have installed Python and matplotlib), check if you can find this file in /Users/Zhangnan/anaconda/lib/.
If you find that file there, set your LD_LIBRARY_PATH:
export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/Users/Zhangnan/anaconda/lib/
You may also want to add that line to your ${HOME}/.bashrc file.

Problem importing pylab in Ubuntu 8.1

I have installed numpy1.3,scipy 0.7.1,matplotlib 0.99.1.1 and python 2.5
when I import pylab I get the following error. Someone please help.
/var/lib/python-support/python2.5/gtk-2.0/gtk/__init__.py:72: GtkWarning: could not open display
warnings.warn(str(e), _gtk.Warning)
/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py:44: GtkWarning: gdk_cursor_new_for_display: assertion `GDK_IS_DISPLAY (display)' failed
cursors.MOVE : gdk.Cursor(gdk.FLEUR),
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.5/site-packages/pylab.py", line 1, in <module>
from matplotlib.pylab import *
File "/usr/lib/python2.5/site-packages/matplotlib/pylab.py", line 247, in <module>
from matplotlib.pyplot import *
File "/usr/lib/python2.5/site-packages/matplotlib/pyplot.py", line 78, in <module>
new_figure_manager, draw_if_interactive, show = pylab_setup()
File "/usr/lib/python2.5/site-packages/matplotlib/backends/__init__.py", line 25, in pylab_setup
globals(),locals(),[backend_name])
File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtkagg.py", line 10, in <module>
from matplotlib.backends.backend_gtk import gtk, FigureManagerGTK, FigureCanvasGTK,\
File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py", line 44, in <module>
cursors.MOVE : gdk.Cursor(gdk.FLEUR),
RuntimeError: could not create GdkCursor object
try using a different backend for plotting than Gtk.
Open the python console and type:
>>> import matplotlib
>>> matplotlib.matplotlib_fname()
This will print a file name. Edit this file and modify the section 'Backend' and change Gtk or GtkAgg with any other (see the documentation in the same file), until you get it working.
You can find more information about backends here.
As for why you get an error when you try to use that backend, it depends on how you have installed the libraries and what you have installed on your computer. I would recommend to install matplotlib with synaptic/yum and selecting all optional dependencies.

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