You can switch the matplotlib&#39;s backend by `%matplotlib &lt;backend&gt;`. To switch back to your system&#39;s default backend use `%matplotlib auto` or just simply `%matplotlib`.

There are many backends available such as `gtk`, `qt`, `notebook`, etc. I personally highly recommend the `notebook` (a.k.a. `nbagg`) backend. It is similar to `inline` but interactive, allowing zooming/panning from inside Jupyter.

For more info try: `?%matplotlib` inside an IPython/Jupyter or [IPython&#39;s online documentation][1] 


  [1]: http://ipython.readthedocs.io/en/stable/interactive/magics.html

`plt.ioff()` and `plt.ion()` works like a charm in my Jupyter notebook with the `notebook` as backend (assuming the usual `import matplotlib.pyplot as plt`).

It depends on the exact configuration of your matplotlib, 
but you can switch between inline and one of &#39;osx&#39;, &#39;qt4&#39;, &#39;qt5&#39;, &#39;gtk3&#39;, &#39;wx&#39;, &#39;qt&#39;, &#39;gtk&#39;, &#39;tk&#39; (some are aliases of other). just use `%matplotlib &lt;the one you want&gt;` to switch. Depending on conditions you migh have only access to one of these.

Another possibility is to use `matplotlib.pyplot.close(fig)`. This works for me even though `%matplotlib auto` raises a horrible `wx` error (related to the versions of the GTK development files I have installed in `LD_LIBRARY_PATH`).

While this might cause problems if you&#39;re doing something like making a video (or it might not; haven&#39;t tried), it worked for me when assembling images in a table using `IPython.display.HTML` per [this answer][1].


  [1]: https://stackoverflow.com/questions/44741809/in-an-html-table-how-to-add-text-beside-plot-in-jupyter-notebook-using-python

I am trying to decide whether I should use Django&#39;s `Client` or `RequestFactory` to test my views.

I am creating my server using DjangoRESTFramework and it&#39;s really simple, so far:

    class SimpleModelList(generics.ListCreateAPIView):
        &quot;&quot;&quot;
        Retrieve list of all route_areas or create a new one.
        &quot;&quot;&quot;
        queryset = SimpleModel.objects.all()
        serializer_class = SimpleModelSerializer
        filter_backends = (IsOwnerFilterBackend,)
        
        def perform_create(self, serializer):
            serializer.save(owner=self.request.user)

What are the differences between testing with Django&#39;s `Client` and `RequestFactory` and which approach is more suited for testing a REST server (if there is any difference besides liking one better)?

Should I create tests with both so as to provide a better coverage for my system?

Django test RequestFactory vs Client

I use reveal.js and write my slides in Markdown code. Now I want to display my content (text, unordered list of bullet points or even an image) in a classical two-column text layout. I would prefer a solution which may be more complex in initial configuration as long as the actual writing of content in Markdown remains easy.

Since I prefer not to run a local server, I write my markdown within the main HTML file.

Update: As the first answer indicates this should be achieved with CSS. (I updated my question accordingly.) Still, I couldn&#39;t find any description how to do it with CSS.

How to use two-column layout with reveal.js?

If I start an ipython notebook with matplotlib inlined, is there a way to subsequently plot a figure so that it shows in the &quot;standard&quot;, non-inlined, way, without having to reload the notebook without the inline command?  I&#39;d like to be able to have some figures inlined int he notebook, but others in the traditional interactive mode, where I can zoom and pan.

matplotlib python inline on/off

<p>If I start an ipython notebook with matplotlib inlined, is there a way to subsequently plot a figure so that it shows in the "standard", non-inlined, way, without having to reload the notebook without the inline command?  I'd like to be able to have some figures inlined int he notebook, but others in the traditional interactive mode, where I can zoom and pan.</p>


My python script uses matplotlib to plot a 2D &quot;heat map&quot; of an x, y, z dataset. My x- and y-values represent amino acid residues in a protein and can therefore only be integers. When I zoom into the plot, it looks like this:

![2D heat map with float tick marks][1]

As I said, float values on the x-y axes do not make sense with my data and I therefore want it to look like this:
![enter image description here][2]

Any ideas how to achieve this?
This is the code that generates the plot:

    def plotDistanceMap(self):
		# Read on x,y,z
		x = self.currentGraph[&#39;xData&#39;]
		y = self.currentGraph[&#39;yData&#39;]
		X, Y = numpy.meshgrid(x, y)
		Z = self.currentGraph[&#39;zData&#39;]
		# Define colormap
		cmap = colors.ListedColormap([&#39;blue&#39;, &#39;green&#39;, &#39;orange&#39;, &#39;red&#39;])
		cmap.set_under(&#39;white&#39;)
		cmap.set_over(&#39;white&#39;)
		bounds = [1,15,50,80,100]
		norm = colors.BoundaryNorm(bounds, cmap.N)
		# Draw surface plot
		img = self.axes.pcolor(X, Y, Z, cmap=cmap, norm=norm)
		self.axes.set_xlim(x.min(), x.max())
		self.axes.set_ylim(y.min(), y.max())
		self.axes.set_xlabel(self.currentGraph[&#39;xTitle&#39;])
		self.axes.set_ylabel(self.currentGraph[&#39;yTitle&#39;])
		# Cosmetics
		#matplotlib.rcParams.update({&#39;font.size&#39;: 12})
		xminorLocator = MultipleLocator(10)
		yminorLocator = MultipleLocator(10)
		self.axes.xaxis.set_minor_locator(xminorLocator)
		self.axes.yaxis.set_minor_locator(yminorLocator)
		self.axes.tick_params(direction=&#39;out&#39;, length=6, width=1)
		self.axes.tick_params(which=&#39;minor&#39;, direction=&#39;out&#39;, length=3, width=1)
		self.axes.xaxis.labelpad = 15
		self.axes.yaxis.labelpad = 15
		# Draw colorbar
		colorbar = self.figure.colorbar(img, boundaries = [0,1,15,50,80,100], 
										spacing = &#39;proportional&#39;,
										ticks = [15,50,80,100], 
										extend = &#39;both&#39;)
		colorbar.ax.set_xlabel(&#39;Angstrom&#39;)
		colorbar.ax.xaxis.set_label_position(&#39;top&#39;)
		colorbar.ax.xaxis.labelpad = 20
		self.figure.tight_layout()		
		self.canvas.draw()

  [1]: http://i.stack.imgur.com/Zg4Xw.jpg
  [2]: http://i.stack.imgur.com/pMQ9N.jpg

Matplotlib: How to force integer tick labels?

I&#39;m trying to plot a ROC curve using seaborn (python).
With matplotlib I simply use the function `plot`:

    plt.plot(one_minus_specificity, sensitivity, &#39;bs--&#39;)

where `one_minus_specificity` and `sensitivity` are two lists of paired values.

Is there a simple counterparts of the plot function in seaborn? I had a look at the gallery but I didn&#39;t find any straightforward method.

Simple line plots using seaborn

I have an existing plot that was created with pandas like this:

    df[&#39;myvar&#39;].plot(kind=&#39;bar&#39;)

The y axis is format as float and I want to change the y axis to percentages.  All of the solutions I found use ax.xyz syntax and **I can only place code below the line above that creates the plot** (I cannot add ax=ax to the line above.) 

**How can I format the y axis as percentages without changing the line above?**

Here is the solution I found **but requires that I redefine the plot**:

    import matplotlib.pyplot as plt
    import numpy as np
    import matplotlib.ticker as mtick
    
    data = [8,12,15,17,18,18.5]
    perc = np.linspace(0,100,len(data))
    
    fig = plt.figure(1, (7,4))
    ax = fig.add_subplot(1,1,1)
    
    ax.plot(perc, data)
    
    fmt = &#39;%.0f%%&#39; # Format you want the ticks, e.g. &#39;40%&#39;
    xticks = mtick.FormatStrFormatter(fmt)
    ax.xaxis.set_major_formatter(xticks)
    
    plt.show()

Link to the above solution: https://stackoverflow.com/questions/26294360/pyplot-using-percentage-on-x-axis

Format y axis as percent

I have a small DataFrame that I want to plot using pandas.

    	2	3
    0	1300	1000
    1	242751149	199446827
    2	237712649	194704827
    3	16.2	23.0

I am still trying to learn plotting from within pandas . I want a plot In the above example when I say .

    df.plot()
    
I get the strangest error.

    Library/Python/2.7/site-packages/pandas-0.16.2-py2.7-macosx-10.10-intel.egg/pandas/tools/plotting.pyc in _compute_plot_data(self)
       1015         if is_empty:
       1016             raise TypeError(&#39;Empty {0!r}: no numeric data to &#39;
    -&gt; 1017                             &#39;plot&#39;.format(numeric_data.__class__.__name__))
       1018 
       1019         self.data = numeric_data
    
    TypeError: Empty &#39;DataFrame&#39;: no numeric data to plot

While I understand that the DataFrame with its very lopsided values makes a very un-interesting plot. I am wondering why the error message complains of no numeric data to plot.


pandas DataFrame &quot;no numeric data to plot&quot; error

I want to draw a figure in matplotib where the axis are displayed within the plot itself not on the side

I have tried the following code [from here][1]:

    import math
    import numpy as np
    import matplotlib.pyplot as plt

    def sigmoid(x):
        a = []
        for item in x:
            a.append(1/(1+math.exp(-item)))
        return a

    x = np.arange(-10., 10., 0.2)
    sig = sigmoid(x)

    plt.plot(x,sig)
    plt.show()

The above code displays the figure like this:  
[![][2]][2]

What I would like to draw is something as follows ([image][3] from Wikipedia)

[![][4]][4]

This [question][5] describes a similar problem, but it draws a reference line in the middle but no axis.


  [1]: http://squall0032.tumblr.com/post/77300791096/plotting-a-sigmoid-function-using
  [2]: http://i.stack.imgur.com/IYMGR.png
  [3]: https://en.wikipedia.org/wiki/File:Gjl-t(x).svg
  [4]: http://i.stack.imgur.com/LHwY1.png
  [5]: https://stackoverflow.com/questions/5394527/how-to-draw-an-axis-in-the-middle-of-the-figure-using-matplotlib

How to draw axis in the middle of the figure?

I&#39;ve been trying to setup an ipython server following several tutorials (since none was exactly my case). A couple days ago, I did manage to get it to the point where it was launching but then was not able to access it via url. Today it&#39;s not launching anymore and I can&#39;t find much about this specific error I get:

    Traceback (most recent call last):
      File &quot;/usr/local/bin/ipython&quot;, line 9, in &lt;module&gt;
        load_entry_point(&#39;ipython==4.0.0-dev&#39;, &#39;console_scripts&#39;, &#39;ipython&#39;)()
      File &quot;/usr/local/lib/python2.7/dist-packages/ipython-4.0.0_dev-py2.7.egg/IPython/__init__.py&quot;, line 118, in start_ipython
        return launch_new_instance(argv=argv, **kwargs)
      File &quot;/usr/local/lib/python2.7/dist-packages/traitlets-4.0.0-py2.7.egg/traitlets/config/application.py&quot;, line 591, in launch_instance
        app.initialize(argv)
      File &quot;&lt;string&gt;&quot;, line 2, in initialize
      File &quot;/usr/local/lib/python2.7/dist-packages/traitlets-4.0.0-py2.7.egg/traitlets/config/application.py&quot;, line 75, in catch_config_error
        return method(app, *args, **kwargs)
      File &quot;/usr/local/lib/python2.7/dist-packages/ipython-4.0.0_dev-py2.7.egg/IPython/terminal/ipapp.py&quot;, line 302, in initialize
        super(TerminalIPythonApp, self).initialize(argv)
      File &quot;&lt;string&gt;&quot;, line 2, in initialize
      File &quot;/usr/local/lib/python2.7/dist-packages/traitlets-4.0.0-py2.7.egg/traitlets/config/application.py&quot;, line 75, in catch_config_error
        return method(app, *args, **kwargs)
      File &quot;/usr/local/lib/python2.7/dist-packages/ipython-4.0.0_dev-py2.7.egg/IPython/core/application.py&quot;, line 386, in initialize
        self.parse_command_line(argv)
      File &quot;/usr/local/lib/python2.7/dist-packages/ipython-4.0.0_dev-py2.7.egg/IPython/terminal/ipapp.py&quot;, line 297, in parse_command_line
        return super(TerminalIPythonApp, self).parse_command_line(argv)
      File &quot;&lt;string&gt;&quot;, line 2, in parse_command_line
      File &quot;/usr/local/lib/python2.7/dist-packages/traitlets-4.0.0-py2.7.egg/traitlets/config/application.py&quot;, line 75, in catch_config_error
        return method(app, *args, **kwargs)
      File &quot;/usr/local/lib/python2.7/dist-packages/traitlets-4.0.0-py2.7.egg/traitlets/config/application.py&quot;, line 487, in parse_command_line
        return self.initialize_subcommand(subc, subargv)
      File &quot;&lt;string&gt;&quot;, line 2, in initialize_subcommand
      File &quot;/usr/local/lib/python2.7/dist-packages/traitlets-4.0.0-py2.7.egg/traitlets/config/application.py&quot;, line 75, in catch_config_error
        return method(app, *args, **kwargs)
      File &quot;/usr/local/lib/python2.7/dist-packages/traitlets-4.0.0-py2.7.egg/traitlets/config/application.py&quot;, line 418, in initialize_subcommand
        subapp = import_item(subapp)
      File &quot;build/bdist.linux-x86_64/egg/ipython_genutils/importstring.py&quot;, line 31, in import_item
    ImportError: No module named notebook.notebookapp

So about the setup, I have installed the anaconda distrib of ipython, pyzmq &amp; tornado libraries. I have created a profile nbserver and the config file is as follows - ipython.config.py:

    c = get_config()
    c.IPKernalApp.pylab = &#39;inline&#39;
    c.NotebookApp.certfile = u&#39;/home/ludo/.ipython/profile_nbserver/mycert.pem&#39;
    c.NotebookApp.ip = &#39;*&#39;
    c.NotebookApp.open_browser = False
    c.NotebookApp.password = u&#39;sha1:e6cb2aa9a[...]&#39;
    c.NotebookApp.port = 9999
    c.NotebookManager.notebook_dir = u&#39;/var/www/ipynb/&#39;
    c.NotebookApp.base_project_url = &#39;/ipynb/&#39;
    c.NotebookApp.base_kernel_url = &#39;/ipynb/&#39;
    c.NotebookApp.webapp_settings = {&#39;static_url_prefix&#39;:&#39;/ipynb/static/&#39;}

I really don&#39;t know where to look for clues anymore - and I&#39;m probably lacking a greater understanding of how all this works to figure it out. My ultimate goal is to then use the answer to [this question][1] on SO to complete a setup behind apache and eventually connect it to colaboratory - but seems like it should launch first.

Many thanks for any help :)


  [1]: https://stackoverflow.com/questions/23890386/how-to-run-ipython-behind-an-apache-proxy

ipython server can&#39;t launch: No module named notebook.notebookapp

Is there a way to selectively hide one specific input or output cell in IPython notebook?

I could only find the below code to show / hide all input cells. 

http://blog.nextgenetics.net/?e=102

But what if I only want to hide the first input cell of a notebook? 

How to hide one specific cell (input or output) in IPython Notebook?

I installed anaconda to use pandas and scipy. I reading and watching pandas tutorials and they all say to open the ipython notebook using
   

     ipython notebook --pylab==inline

but when I do that I get a message saying

    &quot;Support for specifying --pylab on the command line has been removed. Please use &#39;%pylab = inline&#39; or &#39;%matplotlib =inline&#39; in the notebook itself&quot;

But that does not work. Then when I try &quot;plot(arange(10))&quot; I get a message saying &quot;name &#39;plot&#39; is not defined.&quot; I trying plotting data from a .csv file and got

    &quot;matplotlib.axes._subplots.AxesSubplot at 0xebf8b70&quot;.

What should I do?

Jupyter (IPython) notebook not plotting

I&#39;ve recently stopped using `macports` so the kernel.json files I had for various IPython kernels are out of date. I have renamed `~/.ipython` and removed `~/.jupyter` but kernels launched are failing to start with `file not found` errors.

More tellingly, when I run `jupyter-kernelspec list` it still lists all the old kernels I had set up. Where is it getting this information from and what do I need to do to refresh/remove its cache?

How do I delete/refresh available kernels for IPython/Jupyter notebook v4.0?

As I know, `%debug magic` can do debug within one cell.

However, I have function calls across multiple cells.

For example,

    In[1]: def fun1(a)
               def fun2(b)
                   # I want to set a breakpoint for the following line #
                   return do_some_thing_about(b)
    
           return fun2(a)
    
    In[2]: import multiprocessing as mp
           pool=mp.Pool(processes=2)
           results=pool.map(fun1, 1.0)
           pool.close()
           pool.join

What I tried:     
     
1. I tried to set `%debug` in the first line of cell-1. But it enter into debug mode immediately, even before executing cell-2.  
   
2. I tried to add `%debug` in the line right before the code `return do_some_thing_about(b)`. But then the code runs forever, never stops.


What is the right way to set a break point within the ipython notebook?


What is the right way to debug in iPython notebook?


What do you recommend guys for this error when I type in console `ipython notebook` and got 

&gt; ImportError: No module named notebook.notebookapp 

?

I installed ipython notebook with pip and really I don&#39;t know what is going on. 

ImportError: No module named notebook.notebookapp

Jupyter (iPython) notebook is deservedly known as a good tool for prototyping the code and doing all kinds of machine learning stuff interactively. But when I use it, I inevitably run into the following:

 - the notebook quickly becomes too complex and messy to be maintained and improved further as notebook, and I have to make python scripts out of it;
 - when it comes to production code (e.g. one that needs to be re-run every day), the notebook again is not the best format.

Suppose I&#39;ve developed a whole machine learning pipeline in jupyter that includes fetching raw data from various sources, cleaning the data, feature engineering, and training models after all. Now what&#39;s the best logic to make scripts from it with efficient and readable code? I used to tackle it several ways so far:

 1. Simply convert .ipynb to .py and, with only slight changes, hard-code all the pipeline from the notebook into one python script.
    - &#39;+&#39;: quick
    - &#39;-&#39;: dirty, non-flexible, not convenient to maintain

 2.  Make a single script with many functions (approximately, 1 function for each one or two cell), trying to comprise the stages of the pipeline with separate functions, and name them accordingly. Then specify all parameters and global constants via `argparse`.
    - &#39;+&#39;: more flexible usage; more readable code (if you properly transformed the pipeline logic to functions)
    - &#39;-&#39;: oftentimes, the pipeline is NOT splittable into logically completed pieces that could become functions without any quirks in the code. All these functions are typically needed to be only called once in the script rather than to be called many times inside loops, maps etc. Furthermore, each function typically takes the output of all functions called before, so one has to pass many arguments to each function. 

 3.  The same thing as point (2), but now wrap all the functions inside the class. Now all the global constants, as well as outputs of each method can be stored as class attributes.
    - &#39;+&#39;: you needn&#39;t to pass many arguments to each method -- all the previous outputs already stored as attributes
    - &#39;-&#39;: the overall logic of a task is still not captured -- it is data and machine learning pipeline, not just class. The only goal for the class is to be created, call all the methods sequentially one-by-one and then be removed. On top of this, classes are quite long to implement.

 4.  Convert a notebook into python module with several scripts. I didn&#39;t try this out, but I suspect this is the longest way to deal with the problem.

I suppose, this overall setting is very common among data scientists, but surprisingly I cannot find any useful advice around.

Folks, please, share your ideas and experience. Have you ever encountered this issue? How have you tackled it?

Best practices for turning jupyter notebooks into python scripts

I use Jupyter Notebook to run a series of experiments that take some time.
Certain cells take way too much time to execute so it&#39;s normal that I&#39;d like to close the browser tab and come back later. But when I do the kernel interrupts running.

I guess there is a workaround for this but I can&#39;t find it

Content Type	Original Author	Original Content on Stackoverflow
Question	user2379888	View Question on Stackoverflow
Solution 1 - Matplotlib	Gustavo Bezerra	View Answer on Stackoverflow
Solution 2 - Matplotlib	mattmilten	View Answer on Stackoverflow
Solution 3 - Matplotlib	Matt	View Answer on Stackoverflow
Solution 4 - Matplotlib	tsbertalan	View Answer on Stackoverflow

matplotlib python inline on/off

Matplotlib Problem Overview

Matplotlib Solutions

Solution 1 - Matplotlib

Solution 2 - Matplotlib

Solution 3 - Matplotlib

Solution 4 - Matplotlib

How to use two-column layout with reveal.js?

Django test RequestFactory vs Client

Attributions