I use the Python distribution. Python 2.7 x64 with Windows 7 SP1 x64 Ultimate.
After a conda update --all, whenever I try to import matplotlib.pyplot I get ImportError: DLL load failed: %1 is not a valid Win32 application.. Why?
Full error stack:
Traceback (most recent call last):
File "C:\svn\hw4\code\test_con.py", line 1, in <module>
import matplotlib.pyplot as plt
File "C:\Anaconda\lib\site-packages\matplotlib\pyplot.py", line 109, in <module>
_backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
File "C:\Anaconda\lib\site-packages\matplotlib\backends\__init__.py", line 32, in pylab_setup
globals(),locals(),[backend_name],0)
File "C:\Anaconda\lib\site-packages\matplotlib\backends\backend_qt4agg.py", line 17, in <module>
from .backend_qt5agg import NavigationToolbar2QTAgg
File "C:\Anaconda\lib\site-packages\matplotlib\backends\backend_qt5agg.py", line 18, in <module>
from .backend_qt5 import QtCore
File "C:\Anaconda\lib\site-packages\matplotlib\backends\backend_qt5.py", line 31, in <module>
from .qt_compat import QtCore, QtGui, QtWidgets, _getSaveFileName, __version__
File "C:\Anaconda\lib\site-packages\matplotlib\backends\qt_compat.py", line 91, in <module>
from PyQt4 import QtCore, QtGui
ImportError: DLL load failed: %1 is not a valid Win32 application.
I had the same issue after running conda update anaconda. The solution that worked for me was to simply to download the latest windows installer, then uninstall and reinstall.
I suspect this is related to the pathname of your conda environment, as if you do a clean install anaconda now wants to live in C:\Users\yourname\AppData\Local\Continuum\Anaconda2, where previously it was just Anaconda (no 2). I suspect after running the upgrade scripts some things are pointing to the nonexistant (for you) "new" path.
I found that if I explicitly activate a conda environment with activate myenvname before running anything it works fine. Likewise if you you run from the "anaconda prompt" (which activates your default environment for you) it works fine. But to get my default environment to stay active from anywhere like its supposed to I had to reinstall.
Here is what worked for me:
- Run
conda update -f matplotlib (from the Anaconda command prompt)
This gave me a new error:
RuntimeError: module compiled against API version a but this version of numpy is 9
Traceback (most recent call last):
File "C:\svn\hw4\code\test_con.py", line 1, in <module>
import matplotlib.pyplot
File "C:\Anaconda\lib\site-packages\matplotlib\pyplot.py", line 27, in <module>
import matplotlib.colorbar
File "C:\Anaconda\lib\site-packages\matplotlib\colorbar.py", line 32, in <module>
import matplotlib.artist as martist
File "C:\Anaconda\lib\site-packages\matplotlib\artist.py", line 12, in <module>
from .transforms import Bbox, IdentityTransform, TransformedBbox, \
File "C:\Anaconda\lib\site-packages\matplotlib\transforms.py", line 39, in <module>
from matplotlib._path import (affine_transform, count_bboxes_overlapping_bbox,
ImportError: numpy.core.multiarray failed to import
- Run
conda update -f numpy
This gave me a new error:
Traceback (most recent call last):
File "C:\svn\hw4\code\test_con.py", line 1, in <module>
import matplotlib.pyplot
File "C:\Anaconda\lib\site-packages\matplotlib\pyplot.py", line 27, in <module>
import matplotlib.colorbar
File "C:\Anaconda\lib\site-packages\matplotlib\colorbar.py", line 34, in <module>
import matplotlib.collections as collections
File "C:\Anaconda\lib\site-packages\matplotlib\collections.py", line 27, in <module>
import matplotlib.backend_bases as backend_bases
File "C:\Anaconda\lib\site-packages\matplotlib\backend_bases.py", line 56, in <module>
import matplotlib.textpath as textpath
File "C:\Anaconda\lib\site-packages\matplotlib\textpath.py", line 22, in <module>
from matplotlib.mathtext import MathTextParser
File "C:\Anaconda\lib\site-packages\matplotlib\mathtext.py", line 63, in <module>
import matplotlib._png as _png
ImportError: DLL load failed: The specified module could not be found.
- Run
conda install anaconda. This rolled your system back to a stable anaconda distribtution, and solved the issue. (I guess you could skip steps 1 and 2, but I don't feel like going through it again to confirm…)
