Develop Reference

Not able to import netCDF4 to Spyder (Anaconda, OSX10.10)

I'm trying to learn to use Python for scientific analyses (in particular of large NETCDF files), and have installed Anaconda on my MacBookPro OSX10.10. I'm trying to use the Spyder IDE interface, but am stalled by errors with getting the netCDF4 package to work properly.
I need to use the netCDF4 package which I installed using:
conda install netcdf4
First I couldn't get any of the Anaconda packages to import in either Spyder or Python run directly in the terminal, but tried running:
export PATH=~/anaconda/bin:$PATH
Now I get all Anaconda pre-installed packages to work in Spyder (no error when I try the import command), EXCEPT for netCDF 4 which still comes up with the following error:
import netCDF4
Traceback (most recent call last):
File "<ipython-input-7-f731da2de255>", line 1, in <module>
import netCDF4
File "/Users/eriko/anaconda/lib/python2.7/site-packages/netCDF4/__init__.py", line 6, in <module>
from ._netCDF4 import (__version__, __netcdf4libversion__, __hdf5libversion__,
ImportError: cannot import name __netcdf4libversion__
However, netCDF4 imports without any error in the terminal version of Python?
The 'Code Analysis' in Spyder flags the following error in scripts where I added the import netCDF4 command:
'netCDF4' imported but unused
E402 module level import not at top of the file
W292 no newline at the end of file
I've spent too many hour Googling without finding a solution to this, so I hope the Stackoverflow community can help.

Installing Pylab/Matplotlib

I'm trying to write a program that plots a graph, which made me look into
Matplotlib.
I found a tutorial that started out with this little program, that worked fine:
from pylab import *
def main():
X = np.linspace(-np.pi, np.pi, 256, endpoint=True)
C,S = np.cos(X), np.sin(X)
plot(X,C)
plot(X,S)
show()
if __name__ == '__main__':
main()
Then I tried to run it on another computer, where it did not work at all. I tried to download Pylab and Matplotlib. When I had installed Matplotlib it demanded something called dateutil, when I got dateutil it demanded something called six. I downloaded six, but it didn't work properly.
It doesn't feel like I'm on the right track. What should I do to get a proper installation?
EDIT:
I'm using Python 2.7 on Windows 7.
The error I get is
Traceback (most recent call last):
File "C:\Users\Python\mscript\listdb2.py", line 19, in <module>
from pylab import *
File "C:\Python27\lib\site-packages\pylab.py", line 1, in <module>
from matplotlib.pylab import *
File "C:\Python27\lib\site-packages\matplotlib\pylab.py", line 226, in <module>
import matplotlib.finance
File "C:\Python27\lib\site-packages\matplotlib\finance.py", line 21, in <module>
from matplotlib.dates import date2num
File "C:\Python27\lib\site-packages\matplotlib\dates.py", line 119, in <module>
from dateutil.rrule import (rrule, MO, TU, WE, TH, FR, SA, SU, YEARLY,
File "C:\Python27\lib\site-packages\dateutil\rrule.py", line 18, in <module>
from six import advance_iterator, integer_types
ImportError: No module named six
The file six.py is located in C:\python27\Lib\site-packages\six\six.py
The six directory also contains a file called test_six.py. If I try to run this program I also get an error:
Traceback (most recent call last):
File "test_six.py", line 5, in <module>
import.py
ImportError: No module named py

If Anaconda installed and it is already in your environment path, you can get it simply using
conda install matplotlib
in command line and then call in Python with
from pylab import *
This work for me fine as "pip install" and "easy_install" both on Win and Linux caused a lot of issues

Installing packages on *nix is easy using pip. Pip allows you to easily install packages from the Python Package Index (PyPI) with a simple pip install matplotlib. This should install all dependencies, but if it does not then you can install them manually (for instance pip install python-dateutil).
Using pip with Windows is possible though slightly more difficult for packages that require compilers and such. However, installing Python programs on Windows is simple if you use these Windows binaries provided by Christoph Gohlke.
The particular ones for matplotlib can be found here. Note that you can also find similar binaries for python-dateutil, six, etc if necessary.
*As an aside: I would strongly suggest you look into using the full matplotlib.pyplot API rather than pylab. It's much more powerful and useful, but this is just some aside advice :) *

Python - cannot import slycot module in spyder (RuntimeError & ImportError)

When I try to import the slycot module in spyder (version 2.2), I get the following error:
RuntimeError: module compiled against API version 7 but this version of numpy is 6
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Applications/Spyder.app/Contents/Resources/lib/python2.7/slycot/__init__.py",
line 4, in <module>
from slycot.analysis import ab01nd,ab05md,ab05nd,ab07nd,ab08nd, ab09ad
File "/Applications/Spyder.app/Contents/Resources/lib/python2.7/slycot/analysis.py",
line 21, in <module>
from slycot import _wrapper
ImportError: numpy.core.multiarray failed to import
Now, when I import slycot in the python shell through my terminal, there are no problems at all. I think the reason why there are no problems through the terminal, is that I recently installed numpy 1.7.1. Spyder on the other hand still uses numpy 1.6.2.,hence the error.
I tried to change the numpy version in spyder, but so far that didn't work.
When I change the numpy(6) folder in my spyder lib with the recently installed numpy(7), I get the following error (in spyder):
ImportError: Error importing numpy: you should not try to import numpy from
its source directory; please exit the numpy source tree, and relaunch
your python intepreter from there.
What is the best way to solve this error?
Thanks in advance.

(Spyder dev here) At the moment it's not possible for the user to install anything inside the app. I guess you moved your slycot module from another interpreter to our App (because of the numpy error you mention).
The right way to use different modules not present in the app, is to change the path of your interpreter in:
Tools > Preferences > Console > Advanced settings > Python executable
If you installed slycot using your system Python, you have to select
/usr/bin/python

Can't import EasyDialogs - ImportError: No module named _Dlg

I'm trying to use the EasyDialogs python module to produce some simple dialog boxes for my python script on OSX. Whenever I try and import the EasyDialogs module I get the following error:
>>> import EasyDialogs
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Library/Frameworks/EPD64.framework/Versions/6.2/lib/python2.6/plat-mac/EasyDialogs.py", line 24, in <module>
from Carbon.Dlg import GetNewDialog, SetDialogItemText, GetDialogItemText, ModalDialog
File "/Library/Frameworks/EPD64.framework/Versions/6.2/lib/python2.6/plat-mac/Carbon/Dlg.py", line 1, in <module>
from _Dlg import *
ImportError: No module named _Dlg
I've tried doing easy_install Carbon, as I thought it may be due to some issue with the Carbon package for python, but that hasn't helped. Any ideas?

From the paths in your traceback, you appear to be using a 64-bit Enthought Python Distribution. The EasyDialogs module uses various OS X Carbon interfaces, many of which OS X only provides 32-bit versions and have been deprecated by Apple. For this reason, the Python Carbon wrapper and EasyDialogs modules are deprecated in Python 2 and have been removed in Python 3. While they may work in 32-bit mode, you should avoid using them in new code. There are other alternatives available: Tkinter in the standard library, various cross platform GUI frameworks (see here). For more simple dialogs, you could also use the osax package in appscript to use the User Interaction suite of AppleScript's Standard Additions.

Windows XP GTK App Glib Import Error

I am trying to run my GTK app on Windows XP and I am having troubles with an import. I have installed the following as needed and recommended:
python-2.6.msi
gtk2-runtime.2-16.6.exe
pycairo-1.8.6.exe
pygobject-2.20.0
pygtk-2.16.0.exe
pyserial-2.5.exe
However, I am getting the following error when running my script:
Traceback (most recent call last):
File "C:\python26\app\src\start.py", line 22, in <module>
import gtk
File "C:\Python26\Lib\site-packages\gtk-2.0\gtk\__init__.py", line 30, in <mod
ule>
import gobject as _gobject
File "C:\Python26\Lib\site-packages\gtk-2.0\gobject\__init__.py", line 26, in
<module>
from glib import spawn_async, idle_add, timeout_add, timeout_add_seconds, \
File "C:\Python26\Lib\site-packages\gtk-2.0\glib\__init__.py", line 22, in <mo
dule>
from glib._glib import *
ImportError: DLL load failed: The specified module could not be found.
GTK is installed into C:\gtk\bin and is setup in my System PATH.
Am I missing something obvious here?
Any help would be appreciated.
Thank-you kindly.
Andy

I was getting the same issue - I'm not sure why, but I suspect it has something to do with some of the install/lookup paths. I tried adding all sorts of stuff to my path, but nothing seemed to work.
What I did to fix it was to uninstall python et. al. and reinstall using the Python (x,y) package. It's a fairly large download, but it has tons of tools, including several (matplotlib, numpy, scipy, IPython, etc) that I needed/wanted.

You could install pygtk bundle found in this page:
http://ftp.gnome.org/pub/GNOME/binaries/win32/pygtk/2.22/
where you should find the "all in one" installer suited to your version.
It solved the problem to me without having to install Py(x,y), which seems to be a very usefull scientific environment for windows (I use linux and install all these packages from script).