Note that --pylab is deprecated and has been removed from newer builds of IPython,  The recommended way to enable inline plotting in the IPython Notebook is now to run:

    %matplotlib inline
    import matplotlib.pyplot as plt

See [this post](http://mail.scipy.org/pipermail/ipython-dev/2014-March/013411.html) from the ipython-dev mailing list for more details.

Edit:Pylab has been deprecated please see the current accepted answer

Ok, It seems the answer is to start ipython notebook with --pylab=inline. 
so ipython notebook --pylab=inline
This has it do what I saw earlier and what I wanted it to do. 
Sorry about the vague original question. 

With your `import matplotlib.pyplot as plt` just add

    plt.show()

and it will show all stored plots.

simple after importing the matplotlib you have execute one magic if you have started the ipython as like this 

    ipython notebook 

    %matplotlib inline 

run this command everything will be shown perfectly 




start ipython with `ipython notebook --pylab inline` ,then graph will show inline.

    import matplotlib as plt
    %matplotlib as inline

All you need to do is to **import** matplotlib.

    import matplotlib.pyplot as plt 

How can you list all functions in a program with GDB?


Ask GDB to list all functions in a program

I cannot apply stash back to the working directory.

**Little story:**

First I tried to push some committed changes, but it said: &quot;no you can&#39;t, pull first&quot;... OK then, I&#39;ll pull things from GitHub and then push my changes. When I tried to pull, it said that I had changes that would be overwritten, and that I should stash my changes. OK, I stashed the changes... did the pull, and push the committed changes. But now, I cannot restore the uncommitted changes I was working on.

*This is the error:*

    MyPath/File.cs already exists, no checkout
    Could not restore untracked files from stash

For sure I don&#39;t yet understand all the concepts of git, they confuse me a bit... maybe I did something wrong.

It would be great if someone could help me solve this... I&#39;ve been searching google and everything for more than an hour now, and I didn&#39;t come to a solution yet.

Help is much appreciated. Thanks!

Why can&#39;t stash be applied to the working directory?

I am trying to plot some data using pandas in Ipython Notebook, and while it gives me the object, it doesn&#39;t actually plot the graph itself. So it looks like this:

    In [7]:

    pledge.Amount.plot()

    Out[7]:
    
    &lt;matplotlib.axes.AxesSubplot at 0x9397c6c&gt;

The graph should follow after that, but it simply doesn&#39;t appear. I have imported matplotlib, so that&#39;s not the problem. Is there any other module I need to import?


in Ipython notebook / Jupyter, Pandas is not displaying the graph I try to plot

I am trying to plot some data using pandas in Ipython Notebook, and while it gives me the object, it doesn't actually plot the graph itself. So it looks like this:
<pre><code class="hljs language-css">In [7]:

pledge.Amount.plot()

Out[7]:

&#x3C;matplotlib.axes.AxesSubplot at 0x9397c6c>
</code></pre>
The graph should follow after that, but it simply doesn't appear. I have imported matplotlib, so that's not the problem. Is there any other module I need to import?

I have a very simple question. I need to have a second x-axis on my plot and I want that this axis has a certain number of tics that correspond to certain position of the first axis.

Let&#39;s try with an example. Here I am plotting the dark matter mass as a function of the expansion factor, defined as 1/(1+z), that ranges from 0 to 1.


    semilogy(1/(1+z),mass_acc_massive,&#39;-&#39;,label=&#39;DM&#39;)
    xlim(0,1)
    ylim(1e8,5e12)

I would like to have another x-axis, on the top of my plot, showing the corresponding z for some values of the expansion factor. Is that possible? If yes, how can I have xtics ax

How to add a second x-axis in matplotlib

I looked at other questions and can&#39;t figure it out... 

I did the following to install django-debug-toolbar:

1. pip install django-debug-toolbar
2. added to middleware classes:

&gt;     MIDDLEWARE_CLASSES = (
&gt;         &#39;django.middleware.common.CommonMiddleware&#39;,
&gt;         &#39;django.contrib.sessions.middleware.SessionMiddleware&#39;,
&gt;         &#39;django.middleware.csrf.CsrfViewMiddleware&#39;,
&gt;         &#39;django.contrib.auth.middleware.AuthenticationMiddleware&#39;,
&gt;         &#39;django.contrib.messages.middleware.MessageMiddleware&#39;,
&gt;         # Uncomment the next line for simple clickjacking protection:
&gt;         # &#39;django.middleware.clickjacking.XFrameOptionsMiddleware&#39;,
&gt;         &#39;debug_toolbar.middleware.DebugToolbarMiddleware&#39;,
&gt;     )

3 Added INTERNAL_IPS:

&gt; INTERNAL_IPS = (&#39;174.121.34.187&#39;,)

4 Added debug_toolbar to installed apps

I am not getting any errors or anything, and the toolbar doesn&#39;t show up on any page, not even admin.

I even added the directory of the debug_toolbar templates to my `TEMPLATE_DIRS`

django-debug-toolbar not showing up

I&#39;m trying to understand the basics of threading and concurrency. I want a simple case where two threads repeatedly try to access one shared resource. 

The code:  

    import threading
    
    class Thread(threading.Thread):
        def __init__(self, t, *args):
            threading.Thread.__init__(self, target=t, args=args)
            self.start()
    count = 0
    lock = threading.Lock()
    
    def increment():
        global count 
        lock.acquire()
        try:
            count += 1    
        finally:
            lock.release()
       
    def bye():
        while True:
            increment()
            
    def hello_there():
        while True:
            increment()
    
    def main():    
        hello = Thread(hello_there)
        goodbye = Thread(bye)
        
        while True:
            print count

    if __name__ == &#39;__main__&#39;:
        main()

So, I have two threads, both trying to increment the counter. I thought that if thread &#39;A&#39; called `increment()`, the `lock` would be established, preventing &#39;B&#39; from accessing until &#39;A&#39; has released. 

Running the makes it clear that this is not the case. You get all of the random data race-ish increments.

How exactly is the lock object used?  

Additionally, I&#39;ve tried putting the locks inside of the thread functions, but still no luck. 




Python threading. How do I lock a thread?

I&#39;m trying to use one of scikit-learn&#39;s supervised learning methods to classify pieces of text into one or more categories. The predict function of all the algorithms I tried just returns one match.

For example I have a piece of text:

    &quot;Theaters in New York compared to those in London&quot;

And I have trained the algorithm to pick a place for every text snippet I feed it.

In the above example I would want it to return `New York` and `London`, but it only returns `New York`.

Is it possible to use scikit-learn to return multiple results? Or even return the label with the next highest probability? 

Thanks for your help.

---Update 

I tried using `OneVsRestClassifier` but I still only get one option back  per piece of text. Below is the sample code I am using

    y_train = (&#39;New York&#39;,&#39;London&#39;)
    
    
    train_set = (&quot;new york nyc big apple&quot;, &quot;london uk great britain&quot;)
    vocab = {&#39;new york&#39; :0,&#39;nyc&#39;:1,&#39;big apple&#39;:2,&#39;london&#39; : 3, &#39;uk&#39;: 4, &#39;great britain&#39; : 5}
    count = CountVectorizer(analyzer=WordNGramAnalyzer(min_n=1, max_n=2),vocabulary=vocab)
    test_set = (&#39;nice day in nyc&#39;,&#39;london town&#39;,&#39;hello welcome to the big apple. enjoy it here and london too&#39;)
    
    X_vectorized = count.transform(train_set).todense()
    smatrix2  = count.transform(test_set).todense()
    
    
    base_clf = MultinomialNB(alpha=1)
    
    clf = OneVsRestClassifier(base_clf).fit(X_vectorized, y_train)
    Y_pred = clf.predict(smatrix2)
    print Y_pred


Result: [&#39;New York&#39; &#39;London&#39; &#39;London&#39;]

Use scikit-learn to classify into multiple categories

While profiling a piece of python code (`python 2.6` up to `3.2`), I discovered that the
`str` method to convert an object (in my case an integer) to a string is almost an order of magnitude slower than using string formatting.

Here is the benchmark

    &gt;&gt;&gt; from timeit import Timer
    &gt;&gt;&gt; Timer(&#39;str(100000)&#39;).timeit()
    0.3145311339386332
    &gt;&gt;&gt; Timer(&#39;&quot;%s&quot;%100000&#39;).timeit()
    0.03803517023435887

Does anyone know why this is the case?
Am I missing something?

str performance in python

I am just getting started with Pandas and I am reading in a csv file using the [`read_csv()`](http://pandas.pydata.org/pandas-docs/stable/generated/pandas.read_csv.html) method. The difficulty I am having is preventing pandas from converting my telephone numbers to large numbers, instead of keeping them as strings. I defined a converter which just left the numbers alone, but then they still converted to numbers. When I changed my converter to prepend a &#39;z&#39; to the phone numbers, then they stayed strings. Is there some way to keep them strings without modifying the values of the fields?

Specifying data type in Pandas csv reader

I&#39;m using the Pandas package and it creates a DataFrame object, which is basically a labeled matrix. Often I have columns that have long string fields, or dataframes with many columns, so the simple print command doesn&#39;t work well. I&#39;ve written some text output functions, but they aren&#39;t great.

What I&#39;d really love is a simple GUI that lets me interact with a dataframe / matrix / table. Just like you would find in a SQL tool. Basically a window that has a read-only spreadsheet like view into the data. I can expand columns, page up and down through long tables, etc.

I would suspect something like this exists, but I must be Googling with the wrong terms. It would be great if it is pandas specific, but I would guess I could use any matrix-accepting tool. (BTW - I&#39;m on Windows.)

Any pointers?

Or, conversely, if someone knows this space well and knows this probably doesn&#39;t exist, any suggestions on if there is a simple GUI framework / widget I could use to roll my own? (But since my needs are limited, I&#39;m reluctant to have to learn a big GUI framework and do a bunch of coding for this one piece.)


Python / Pandas - GUI for viewing a DataFrame or Matrix

I load some machine learning data from a CSV file. The first 2 columns are observations and the remaining columns are features.

Currently, I do the following:

    data = pandas.read_csv(&#39;mydata.csv&#39;)

which gives something like:

    data = pandas.DataFrame(np.random.rand(10,5), columns = list(&#39;abcde&#39;))

I&#39;d like to slice this dataframe in two dataframes: one containing the columns `a` and `b` and one containing the columns `c`, `d` and `e`.

It is not possible to write something like 

    observations = data[:&#39;c&#39;]
    features = data[&#39;c&#39;:]

I&#39;m not sure what the best method is. Do I need a `pd.Panel`?

By the way, I find dataframe indexing pretty inconsistent: `data[&#39;a&#39;]` is permitted, but `data[0]` is not. On the other side, `data[&#39;a&#39;:]` is not permitted but `data[0:]` is.
Is there a practical reason for this? This is really confusing if columns are indexed by Int, given that `data[0] != data[0:1]`

How to take column-slices of dataframe in pandas

I have a `DataFrame` with a few columns. One columns contains a symbol for which currency is being used, for instance a euro or a dollar sign. Another column contains a budget value. So for instance in one row it could mean a budget of 5000 in euro and in the next row it could say a budget of 2000 in dollar.

In pandas I would like to add an extra column to my DataFrame, normalizing the budgets in euro. So basically, for each row the value in the new column should be the value from the budget column * 1 if the symbol in the currency column is a euro sign, and the value in the new column should be the value of the budget column * 0.78125 if the symbol in the currency column is a dollar sign.

I know how to add a column, fill it with values, copy values from another column etc. but not how to fill the new column conditionally based on the value of another column. 

Any suggestions?

Conditionally fill column values based on another columns value in pandas

How do I create an empty `DataFrame`, then add rows, one by one?

I created an empty `DataFrame`:

    df = pd.DataFrame(columns=(&#39;lib&#39;, &#39;qty1&#39;, &#39;qty2&#39;))

Then I can add a new row at the end and fill a single field with:

    df = df._set_value(index=len(df), col=&#39;qty1&#39;, value=10.0)

It works for only one field at a time. What is a better way to add new row to `df`?


Create a Pandas Dataframe by appending one row at a time

I run ipython 0.12.1 on Ubuntu 12.04. You can run it in browser using notebook interface by running:

    ipython notebook --pylab
Configuration files can be found in `~/.config/ipython/profile_default/`. It seems that connection parameters for every kernel is placed in `~/.config/ipython/profile_default/security/kernel-4e424cf4-ba44-441a-824c-c6bce727e585.json`. Here is the content of this file (new files are created as you start new kernels):

    {
      &quot;stdin_port&quot;: 54204, 
      &quot;ip&quot;: &quot;127.0.0.1&quot;, 
      &quot;hb_port&quot;: 58090, 
      &quot;key&quot;: &quot;2a105dd9-26c5-40c6-901f-a72254d59876&quot;, 
      &quot;shell_port&quot;: 52155, 
      &quot;iopub_port&quot;: 42228
    }
It&#39;s rather self-explanatory but how can I set a server that would have a permanent configuration, so I can use notebook interface from other computers in the LAN?

How to accept connections for ipython from other computers?

I am starting to depend heavily on the IPython notebook app to develop and document algorithms.  It is awesome; but there is something that seems like it should be possible, but I can&#39;t figure out how to do it:

I would like to insert a local image into my (local) IPython notebook markdown to aid in documenting an algorithm.  I know enough to add something like `&lt;img src=&quot;image.png&quot;&gt;` to the markdown, but that is about as far as my knowledge goes.  I assume I could put the image in the directory represented by 127.0.0.1:8888 (or some subdirectory) to be able to access it, but I can&#39;t figure out where that directory is.  (I&#39;m working on a mac.)  So, is it possible to do what I&#39;m trying to do without too much trouble?


Inserting image into IPython notebook markdown

Is it possible to zoom into a plot if inline is activated? Especially regarding to 3d-plots rotating and zooming is a necessary feature. 

ipython notebook --pylab inline: zooming of a plot

I want to copy already indented Python code / whole functions and classes into IPython. Everytime I try the indentation is screwed up and I get following error message:

`IndentationError: unindent does not match any outer indentation level (&lt;ipython-input-23-354f8c8be51b&gt;, line 12)`

`If you want to paste code into IPython, try the %paste and %cpaste magic functions.`


How does IPython&#39;s magic %paste work?

Error reports from most language kernels running in IPython/Jupyter Notebooks indicate the line on which the error occurred; but (at least by default) no line numbers are indicated in Notebooks.

Is it possibile to add the line numbers to IPython/Jupyter Notebooks?

Showing line numbers in IPython/Jupyter Notebooks

I would like to use an [IPython notebook][notebook] as a way to interactively analyze some genome charts I am making with Biopython&#39;s [`GenomeDiagram`][genomediagram] module. While there is extensive documentation on how to use `matplotlib` to get graphs inline in IPython notebook, GenomeDiagram uses the ReportLab toolkit which I don&#39;t think is supported for inline graphing in IPython. 

I was thinking, however, that a way around this would be to write out the plot/genome diagram to a file and then open the image inline which would have the same result with something like this:

    gd_diagram.write(&quot;test.png&quot;, &quot;PNG&quot;)
    display(file=&quot;test.png&quot;)

However, I can&#39;t figure out how to do this - or know if it&#39;s possible. So does anyone know if images can be opened/displayed in IPython?


  [genomediagram]: http://biopython.org/DIST/docs/tutorial/Tutorial.html#sec329
  [notebook]: http://ipython.org/notebook.html

How can I display an image from a file in Jupyter Notebook?

I am trying to obtain the current NoteBook name when running the IPython notebook. I know I can see it at the top of the notebook. What I am after something like

    currentNotebook = IPython.foo.bar.notebookname()

I need to get the name in a variable.

How do I get the current IPython / Jupyter Notebook name

How can I display LaTeX code in a IPython Notebook?

How to write LaTeX in IPython Notebook?

I am using IPython with `--pylab=inline` and would sometimes like to quickly switch to the interactive, zoomable matplotlib GUI for viewing plots (the one that pops up when you plot something in a terminal Python console). How could I do that? Preferably without leaving or restarting my notebook.

The problem with inline plots in IPy notebook is that they are of a limited resolution and I can&#39;t zoom into them to see some smaller parts. With the maptlotlib GUI that starts from a terminal, I can select a rectangle of the graph that I want to zoom into and the axes adjust accordingly. I tried experimenting with 

    from matplotlib import interactive
    interactive(True)

and

    interactive(False)

but that didn&#39;t do anything. I couldn&#39;t find any hint online either.

Content Type	Original Author	Original Content on Stackoverflow
Question	chrisfs	View Question on Stackoverflow
Solution 1 - Python	Tal Yarkoni	View Answer on Stackoverflow
Solution 2 - Python	chrisfs	View Answer on Stackoverflow
Solution 3 - Python	eumiro	View Answer on Stackoverflow
Solution 4 - Python	Ankanna	View Answer on Stackoverflow
Solution 5 - Python	pigletfly	View Answer on Stackoverflow
Solution 6 - Python	TrilochanYadav	View Answer on Stackoverflow
Solution 7 - Python	the curious mind	View Answer on Stackoverflow

in Ipython notebook / Jupyter, Pandas is not displaying the graph I try to plot

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Why can't stash be applied to the working directory?

Ask GDB to list all functions in a program

Attributions