Run nose with the `-s` / `--nocapture` option and you&#39;ll be able to see the pdb prompt and interact with the debugger normally.

If using the commandline that means:-

    python manage.py  test -s [other-opts-and-args]

Nose is capturing the output and redirecting it.  So, the breakpoint is hit, but you just don&#39;t see it.  You need to turn off the output redirection so that the debug output shows up on the screen.

Nose can do this for you, if you use:

    from nose.tools import set_trace; set_trace()

instead of:

    import pdb;pdb.set_trace()

In my case the flag the flag -s/--nocapture, still didn&#39;t resolve it and drop the compiler into pdb.

One other reason that you could look into is if you&#39;re using a database such as MySQL as part of your tests, that it&#39;s not locked by another simultaneous process. In my case, i had started a python shell to query the MySQL database through SQL Alchemy and that had locked up the tables. As a result, my nose tests were hanging - not running/exiting.

I killed the python processes which were locking up the tables and Nose was back up sniffing 

**&gt; $ ps auxww | grep python | awk &#39;{print $2}&#39; | sudo xargs kill -9**



I am using the FOS bundle and I want to retrieve all users with a given ROLE from the database.

What is the best way to do this?

FOS bundle - How to select users with a specific role?

`Implicit instantiation of undefined template &#39;std::basic_ifstream&lt;char,std::char_traits&lt;char&gt;&gt;&#39;`

---
    #ifndef MAPPER_H
    #define MAPPER_H
    #include &lt;iostream&gt;
    #include &lt;string&gt;
    #include &lt;vector&gt;
    #include &quot;KeyValue.h&quot;
    #include &quot;Parser.h&quot;
    
    using namespace std;
    class Mapper
    {
    public:
    	Mapper(ifstream&amp; infile);
    	~Mapper(void);
    	void loadTokens();
    	void showTokens();
    	void map();
    	void printMap();
    	void printMap(string map_fileName);
    private:
        ifstream inFile;  //&lt;-- is where the error is happening
    	vector&lt;string&gt; tokens;
    	vector&lt;KeyValue&gt; map_output;
    	Parser* parser;
    };
    
    #endif

I&#39;ve even tried putting `std::ifstream` and it still doesn&#39;t work.

When I `#include &lt;fstream&gt;` instead of `#include &lt;iostream&gt;`, I get these errors in `fstream.tcc` and `basic_ios.tcc`:

`&#39;operator=&#39; is a private member of &#39;std::basic_streambuf&lt;char&gt;&#39;`

And since that&#39;s part of the fstream library, obviously something i&#39;m doing is wrong...

Anyone able to help?

Why am I getting this ifstream error?

I&#39;m running a suite of tests (.py files) using nosetests.  Using a classic

    import pdb; pdb.set_trace()

the nosetests run just never completes.  It just hangs right where the breakpoint has been set, but never drops into the pdb debugger.

Any ideas why this would be?  I&#39;ve tried moving the breakpoint to a number of different positions (other test functions, other files) to no avail.



pdb.set_trace() causing frozen nosetests, does not drop into debugger

I'm running a suite of tests (.py files) using nosetests. Using a classic
<pre><code class="hljs language-arduino">import pdb; pdb.set_trace()
</code></pre>
the nosetests run just never completes. It just hangs right where the breakpoint has been set, but never drops into the pdb debugger.
Any ideas why this would be? I've tried moving the breakpoint to a number of different positions (other test functions, other files) to no avail.

From a text file containing three columns of data I want to be able to just take a `slice` of data from all three columns where the values in the first column are equal to the values defined in `above`. I then want to put the slice of data into a new array called `slice` (I am using **Python 2.7**)

    above = range(18000, 18060, 5)

    data = np.loadtxt(open(&#39;data.txt&#39;), delimiter=None)

    energies = (np.hsplit(data, 3))[0]

    slice = set(energies)&amp;set(above)

The above comes back with:

    Traceback (most recent call last):
      File &quot;&lt;pyshell#27&gt;&quot;, line 1, in &lt;module&gt;
        set(energies)&amp;set(above)
    TypeError: unhashable type: &#39;numpy.ndarray


TypeError: unhashable type: &#39;numpy.ndarray&#39;

I need to produce a screencast of an ipython session, and to avoid confusing viewers, I want to disable all warnings emitted by ``warnings.warn`` calls from different packages. Is there a way to configure the ipythonrc file to automatically disable all such warnings?

Hide all warnings in ipython

How does one check whether a task is running in celery (specifically, I&#39;m using celery-django)?

I&#39;ve read the documentation, and I&#39;ve googled, but I can&#39;t see a call like:

    my_example_task.state() == RUNNING

My use-case is that I have an external (java) service for transcoding. When I send a document to be transcoded, I want to check if the task that runs that service is running, and if not, to (re)start it.

I&#39;m using the current stable versions - 2.4, I believe.

How to check task status in Celery?

I have to find the average of a list in Python. This is my code so far

    from functools import reduce

    l = [15, 18, 2, 36, 12, 78, 5, 6, 9]
    print(reduce(lambda x, y: x + y, l))

I&#39;ve got it so it adds together the values in the list, but I don&#39;t know how to make it divide into them?

Finding the average of a list

I&#39;m having a hard time finding examples for rotating an image around a specific point by a specific (often very small) angle in Python using OpenCV.

This is what I have so far, but it produces a very strange resulting image, but it is rotated somewhat:

    def rotateImage( image, angle ):
        if image != None:
            dst_image = cv.CloneImage( image )

            rotate_around = (0,0)
            transl = cv.CreateMat(2, 3, cv.CV_32FC1 )

            matrix = cv.GetRotationMatrix2D( rotate_around, angle, 1.0, transl )
            cv.GetQuadrangleSubPix( image, dst_image, transl )
            cv.GetRectSubPix( dst_image, image, rotate_around )

        return dst_image


OpenCV Python rotate image by X degrees around specific point

From what I have read, there are two ways to debug code in Python:

* With a traditional debugger such as `pdb` or `ipdb`. This supports commands such as `c` for `continue`, `n` for `step-over`, `s` for `step-into` etc.), but you don&#39;t have direct access to an IPython shell which can be extremely useful for object inspection.

* Using  **IPython** by [embedding][1] an IPython shell in your code. You can do `from IPython import embed`, and then use `embed()` in your code. When your program/script hits an `embed()` statement, you are dropped into an IPython shell. This allows the full inspection of objects and testing of Python code using all the IPython goodies. However, when using `embed()` you can&#39;t **step-by-step** through the code anymore with handy keyboard shortcuts.


Is there any way to combine the best of both worlds? I.e.

1. Be able to  **step-by-step** through your code with handy pdb/ipdb keyboard shortcuts.
2. At any such step (e.g. on a given statement), have access to a full-fledged **IPython shell**.

### IPython debugging *as in* MATLAB:
An example of this type of &quot;enhanced debugging&quot; can be found  in MATLAB, where the user **always** has full access to the MATLAB engine/shell, and she can still **step-by-step** through her code, define conditional breakpoints, etc. From what I have discussed with other users, this is the debugging feature that people miss the most when moving from MATLAB to IPython.

### IPython debugging in Emacs and other editors:
I don&#39;t want to make the question too specific, but I work mostly in Emacs, so I wonder if there is any way to bring this functionality into it. **Ideally**, Emacs (or the editor) would allow the programmer to set breakpoints anywhere on the code and communicate with the interpreter or debugger to have it stop in the location of your choice, and bring to a full IPython interpreter on that location.

  [1]: http://ipython.org/ipython-doc/dev/interactive/reference.html#embedding-ipython

Step-by-step debugging with IPython

I&#39;m using the pdb module to debug a program. I&#39;d like to understand how I can exit pdb and allow the program to continue onward to completion. The program is computationally expensive to run, so I don&#39;t want to exit without the script attempting to complete. `continue` doesn&#39;t seems to work. How can I exit pdb and continue with my program?

How to exit pdb and allow program to continue?

My code is, for better or worse, rife with single letter variables (it&#39;s physics stuff, so those letters are meaningful), as well as NumPy&#39;s, which I&#39;m often interacting with.  

When using the Python debugger, occasionally I&#39;ll want to look at the value of, say, `n`.  However, when I hit `n&lt;enter&gt;`, that&#39;s the PDB command for `(n)ext`, which has a higher priority.  `print n` works around looking at it, but how can I set it?

How do I manipulate a variable whose name conflicts with PDB commands?

I&#39;m debugging my Python scripts using *pdb* and the manual says I can use **p variables** command to print the values of the specified variables at a certain point. But what if I had lots of variables, like 20 variables, and I would like to track the value of all of them? How do I print all of them without specifying each one manually? Take for example this script:

    a = 1
    b = 2
    c = 3

I can debug it with pdb and print all of them using **p a, b, c** like this:

    $ python -m pdb test.py 
    &gt; /media/test.py(1)&lt;module&gt;()
    -&gt; a = 1
    (Pdb) n
    &gt; /media/test.py(2)&lt;module&gt;()
    -&gt; b = 2
    (Pdb) n
    &gt; /media/test.py(3)&lt;module&gt;()
    (Pdb) n
    --Return--
    &gt; /media/test.py(3)&lt;module&gt;()-&gt;None
    -&gt; c = 3
    (Pdb) p a, b, c
    (1, 2, 3)
    (Pdb) 

But I have to manually specify each variable. Is there a way of print all variables at once, without specifying each one of them?

How to print all variables values when debugging Python with pdb, without specifying each variable?

I have a python script that I suspect that there is a deadlock. I was trying to debug with `pdb` but if I go step by step it doesn&#39;t get the deadlock, and by the output returned I can see that it&#39;s not being hanged on the same iteration. I would like to attach my script to a debugger only when it gets locked, is it possible? I&#39;m open to use other debuggers if necessary.

Attaching a process with pdb

I have a file called test_web.py containing a class TestWeb and many methods named like  test_something().

I can run every test in the class like so:

    $ nosetests test_web.py 
    ...
    ======================================================================
    FAIL: checkout test
    ----------------------------------------------------------------------
    Traceback (most recent call last):
      File &quot;/Users/me/path/here/test_web.py&quot;, line 187, in test_checkout
    ...

But I can’t seem to run individual tests. These give me “No such test” errors when run in the same PWD:

    $ nosetests test_web.py:test_checkout
    $ nosetests TestWeb:test_checkout

What could be wrong here?


How do I specify a single test in a file with nosetests?

I&#39;ve searched for documentation, but couldn&#39;t find any. There were a couple that didn&#39;t explain much.

Can someone explain to me Nose&#39;s 
  
    assert_raises(what should I put here?)
function and how to use it?

Content Type	Original Author	Original Content on Stackoverflow
Question	Bodhi	View Question on Stackoverflow
Solution 1 - Python	stderr	View Answer on Stackoverflow
Solution 2 - Python	Joe L.	View Answer on Stackoverflow
Solution 3 - Python	Shankar ARUL	View Answer on Stackoverflow

pdb.set_trace() causing frozen nosetests, does not drop into debugger

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

Solution 3 - Python

Why am I getting this ifstream error?

FOS bundle - How to select users with a specific role?

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