Have you tried `pip install coverage`? The coverage plugin depends on separate coverage module, which is not a nose&#39;s dependency, so needs to be installed manually.

Validate if the coverage module is working by itself via `coverage --version`. I had a case that it was not working due to the lack of SQLite modules in my python installation from the source. I reinstalled python with SQLite extension to fix the issue.

I have a resource called Books.  It&#39;s listed as a resource properly in my routes file.

I have a new action, which gives the new view the standard:

    @book = Book.new

On the model, there are some attributes which are validated by presence, so if a save action fails, errors will be generated.

In my controller:

    @book = Book.create
    ...  # some logic
    if @book.save
      redirect_to(@book)
    else
      render :new
    end

This is pretty standard; and the rationale for using render:new is so that the object is passed back to the view and errors can be reported, form entries re-filled, etc.

This works, except every time I&#39;m sent back to the form (via render :new), my errors show up, but my URL is the INDEX URL, which is 

    /books

Rather than 

    /books/new

Which is where I started out in the first place.  I have seen several others posts about this problem, but no answers.  At a minimum, one would assume it would land you at /books/create, which I also have a view file for (identical to new in this case).  

I can do this:

    # if the book isn&#39;t saved then
    flash[:error] = &quot;Errors!&quot;
    redirect_to new_book_path

But then the @book data is lost, along with the error messages, which is the entire point of having the form and the actions, etc.  

Why is render :new landing me at /books, my index action, when normally that URL calls the INDEX method, which lists all the books?

In Rails when a resource create action fails and calls render :new, why must the URL change to the resource&#39;s index url?

Is it possible to append a single character to the end of `array` or `string` in java. Example:    
    
    private static void /*methodName*/ () {            
        String character = &quot;a&quot;
        String otherString = &quot;helen&quot;;
        //this is where i need help, i would like to make the otherString become 
        // helena, is there a way to do this?               
    }

Append a single character to a string or char array in java?

I can&#39;t seem to get code coverage with Nose to work, despite having the plugin installed.

Any ideas on how to fix this?

    12:15:25 ~/sandbox/ec$ nosetests --plugins
    Plugin xunit
    Plugin deprecated
    Plugin skip
    Plugin multiprocess
    Plugin failuredetail
    Plugin capture
    Plugin logcapture
    Plugin coverage
    Plugin attributeselector
    Plugin doctest
    Plugin profile
    Plugin id
    Plugin allmodules
    Plugin collect-only
    Plugin isolation
    Plugin pdb

    12:15:34 ~/sandbox/ec$ nosetests -v --with-coverage
    nose.plugins.cover: ERROR: Coverage not available: unable to import coverage module
    tests.edgecast_client_tests.test_log ... ok
    
    ----------------------------------------------------------------------
    Ran 1 test in 0.206s
    
    OK

How to Fix Python Nose: Coverage not available: unable to import coverage module

I can't seem to get code coverage with Nose to work, despite having the plugin installed.
Any ideas on how to fix this?
<pre><code class="hljs language-javascript">12:15:25 ~/sandbox/ec$ nosetests --plugins
Plugin xunit
Plugin deprecated
Plugin skip
Plugin multiprocess
Plugin failuredetail
Plugin capture
Plugin logcapture
Plugin coverage
Plugin attributeselector
Plugin doctest
Plugin profile
Plugin id
Plugin allmodules
Plugin collect-only
Plugin isolation
Plugin pdb

12:15:34 ~/sandbox/ec$ nosetests -v --with-coverage
nose.plugins.cover: ERROR: Coverage not available: unable to import coverage module
tests.edgecast_client_tests.test_log ... ok

----------------------------------------------------------------------
Ran 1 test in 0.206s

OK
</code></pre>

When using nose 1.2.1 with Python 3.3.0, I sometimes get an error message similar to the following one

    ======================================================================
    FAIL: maxdiff2.test_equal
    ----------------------------------------------------------------------
    Traceback (most recent call last):
      File &quot;/usr/local/lib/python3.3/site-packages/nose/case.py&quot;, line 198, in runTest
        self.test(*self.arg)
      File &quot;/Users/loic/cmrsj/Calculus_II/scrap/maxdiff2.py&quot;, line 32, in test_equal
        assert_equal(str1, str2)
    AssertionError: &#39;Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a
    diam lectus.\n [truncated]... != &#39;Suspendisse lectus leo, consectetur in tempor sit
    amet, placerat quis neque.\nE [truncated]...
    Diff is 1780 characters long. Set self.maxDiff to None to see it.
    
    ----------------------------------------------------------------------
    Ran 1 test in 0.064s
    
    FAILED (failures=1)

In many situations, to figure out what the error really is, I need to see the full diff output.  However, I have no idea of how to set that `self.maxDiff`.  Googling for nose and maxDiff does not help.  With the same version of nose on Python 2.7.1 the full diff is printed to screen.

Here is a simple script that generates the error above when run with `nosetests-3.3`:

    from nose.tools import assert_equal
    
    def test_equal():
        str1 = &quot;&quot;&quot;\
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus.
    Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec
    consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero
    egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem
    lacinia consectetur. Donec ut libero sed arcu vehicula ultricies a non tortor.
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean ut gravida
    lorem. Ut turpis felis, pulvinar a semper sed, adipiscing id dolor.
    Pellentesque auctor nisi id magna consequat sagittis. Curabitur dapibus enim
    sit amet elit pharetra tincidunt feugiat nisl imperdiet. Ut convallis libero in
    urna ultrices accumsan. Donec sed odio eros. Donec viverra mi quis quam
    pulvinar at malesuada arcu rhoncus. Cum sociis natoque penatibus et magnis dis
    parturient montes, nascetur ridiculus mus. In rutrum accumsan ultricies. Mauris
    vitae nisi at sem facilisis semper ac in est.&quot;&quot;&quot;
    
        str2 = &quot;&quot;&quot;\
    Suspendisse lectus leo, consectetur in tempor sit amet, placerat quis neque.
    Etiam luctus porttitor lorem, sed suscipit est rutrum non. Curabitur lobortis
    nisl a enim congue semper. Aenean commodo ultrices imperdiet. Vestibulum ut
    justo vel sapien venenatis tincidunt. Phasellus eget dolor sit amet ipsum
    dapibus condimentum vitae quis lectus. Aliquam ut massa in turpis dapibus
    convallis. Praesent elit lacus, vestibulum at malesuada et, ornare et est. Ut
    augue nunc, sodales ut euismod non, adipiscing vitae orci. Mauris ut placerat
    justo. Mauris in ultricies enim. Quisque nec est eleifend nulla ultrices
    egestas quis ut quam. Donec sollicitudin lectus a mauris pulvinar id aliquam
    urna cursus. Cras quis ligula sem, vel elementum mi. Phasellus non ullamcorper
    urna.&quot;&quot;&quot;
    
        assert_equal(str1, str2)

How to set self.maxDiff in nose to get full diff output?

I&#39;m working on a program (python ,opencv) in which I use the `spacebar` to go to the next frame, and `Esc` to exit the program. These are the only two keys i&#39;ve got working. I tried to find out about more keys , tried various codes for them but didnt work. especially arrow keys.

I found **[this][1]** about `waitkey`, but it doesn&#39;t work.

So my question is, How do I catch other keys besides `esc` and `spacebar` to trigger certain functions in my python-opencv program?


  [1]: http://pklaus.github.com/HHG-Analysis-Python/helpers.html#module-keycode

Using other keys for the waitKey() function of opencv

So I have a long list of strings in the same format, and I want to find the last &quot;.&quot; character in each one, and replace it with &quot;. - &quot;. I&#39;ve tried using rfind, but I can&#39;t seem to utilize it properly to do this.

Finding last occurrence of substring in string, replacing that

In Python I have a **module** myModule.py where I define a few functions and a **main()**, which takes a few command line arguments. 

I usually call this main() from a bash script. Now, I would like to put everything into a small **package**, so I thought that maybe I could turn my simple bash script into a Python script and put it in the package.

So, how do I actually **call the main()** function of myModule.py **from the main() function** of MyFormerBashScript.py? Can I even do that? How do I pass any **arguments** to it?



In Python, can I call the main() of an imported module?

Is it possible to create a dictionary comprehension in Python (for the keys)?

Without list comprehensions, you can use something like this:

    l = []
    for n in range(1, 11):
        l.append(n)

We can shorten this to a list comprehension: `l = [n for n in range(1, 11)]`.

However, say I want to set a dictionary&#39;s keys to the same value.
I can do:

    d = {}
    for n in range(1, 11):
         d[n] = True # same value for each

I&#39;ve tried this:

    d = {}
    d[i for i in range(1, 11)] = True

However, I get a `SyntaxError` on the `for`.

In addition (I don&#39;t need this part, but just wondering), can you set a dictionary&#39;s keys to a bunch of different values, like this:

    d = {}
    for n in range(1, 11):
        d[n] = n

Is this possible with a dictionary comprehension?

    d = {}
    d[i for i in range(1, 11)] = [x for x in range(1, 11)]

This also raises a `SyntaxError` on the `for`.

Python Dictionary Comprehension

At the moment I am running `python manage.py test` every once in a while after I make significant changes in my django project. Is it possible to run those tests automatically whenever I change and save a file in my project? It&#39;ll be useful to detect bugs earlier (I know rails has something like this with rspec). I am using nose and django-nose. Thanks in advance.

How to automatically run tests when there&#39;s any change in my project (Django)?

I have a function I want to unit test contains calls two other functions. I am unsure how can I mock both functions at the same time properly using patch. I have provided an example of what I mean below. When I run nosetests, the tests pass but I feel that there must be a cleaner way to do this and I do not really Understand the piece regarding f.close()...

The directory structure looks like this:

    program/
      program/
        data.py
      tests/
        data_test.py

data.py:

    import cPickle
    
    def write_out(file_path, data):
        f = open(file_path, &#39;wb&#39;)
        cPickle.dump(data, f)
        f.close()

data_test.py:

    from mock import MagicMock, patch
    
    def test_write_out():
        path = &#39;~/collection&#39;
        mock_open = MagicMock()
        mock_pickle = MagicMock()
        f_mock = MagicMock()
        with patch(&#39;__builtin__.open&#39;, mock_open):
            f = mock_open.return_value
            f.method.return_value = path
            with patch(&#39;cPickle.dump&#39;, mock_pickle):
                write_out(path, &#39;data&#39;)
                mock_open.assert_called_once_with(&#39;~/collection&#39;, &#39;wb&#39;)
                f.close.assert_any_call()
                mock_pickle.assert_called_once_with(&#39;data&#39;, f)

Results:

    $ nosetests
    .
    ----------------------------------------------------------------------
    Ran 1 test in 0.008s
    OK

Mocking two functions with patch for a unit test

I&#39;m trying to figure out how to get `python setup.py test` to run the equivalent of `python -m unittest discover`.  I don&#39;t want to use a run_tests.py script and I don&#39;t want to use any external test tools (like `nose` or `py.test`).  It&#39;s OK if the solution only works on python 2.7.

In `setup.py`, I think I need to add something to the `test_suite` and/or `test_loader` fields in config, but I can&#39;t seem to find a combination that works correctly:

    config = {
        &#39;name&#39;: name,
        &#39;version&#39;: version,
        &#39;url&#39;: url,
        &#39;test_suite&#39;: &#39;???&#39;,
        &#39;test_loader&#39;: &#39;???&#39;,
    }

**Is this possible using only `unittest` built into python 2.7?**

FYI, my project structure looks like this:

    project/
      package/
        __init__.py
        module.py
      tests/
        __init__.py
        test_module.py
      run_tests.py &lt;- I want to delete this
      setup.py

**Update**: This is possible with `unittest2` but I want find something equivalent using only `unittest`

From https://pypi.python.org/pypi/unittest2

&gt; unittest2 includes a very basic setuptools compatible test collector. Specify test_suite = &#39;unittest2.collector&#39; in your setup.py. This starts test discovery with the default parameters from the directory containing setup.py, so it is perhaps most useful as an example (see unittest2/collector.py).

For now, I&#39;m just using a script called `run_tests.py`, but I&#39;m hoping I can get rid of this by moving to a solution that only uses `python setup.py test`.

Here&#39;s the `run_tests.py` I&#39;m hoping to remove:

    import unittest

    if __name__ == &#39;__main__&#39;:
        
        # use the default shared TestLoader instance
        test_loader = unittest.defaultTestLoader
        
        # use the basic test runner that outputs to sys.stderr
        test_runner = unittest.TextTestRunner()
        
        # automatically discover all tests in the current dir of the form test*.py
        # NOTE: only works for python 2.7 and later
        test_suite = test_loader.discover(&#39;.&#39;)
        
        # run the test suite
        test_runner.run(test_suite)

How to run unittest discover from &quot;python setup.py test&quot;?

I have two files

spike.py
    
    class T1(object):
        def foo(self, afd):
            return &quot;foo&quot;
    
        def get_foo(self):
            return self.foo(1)
    
    
    def bar():
        return &quot;bar&quot;

test_spike.py:
    
    from unittest import TestCase
    import unittest
    from mock import patch, MagicMock
    from spike import T1, bar
    
    
    class TestStuff(TestCase):
        @patch(&#39;spike.T1.foo&#39;, MagicMock(return_value=&#39;patched&#39;))
        def test_foo(self):
            foo = T1().get_foo()
            self.assertEqual(&#39;patched&#39;, foo)
    
        @patch(&#39;spike.bar&#39;)
        def test_bar(self, mock_obj):
            mock_obj.return_value = &#39;patched&#39;
            bar = bar()
            self.assertEqual(&#39;patched&#39;, bar)
    
    
    if __name__ == &quot;__main__&quot;:
        unittest.main()

When I run `python test_spike.py`, the first test case would pass, but the second would fail.
and I switch to use `nosetests test_spike.py`, then both two are failed.

I don&#39;t understand how this happened? These cases supposed to pass all.

Why python mock patch doesn&#39;t work?

I have just started writing some unit tests for a python project I have using `unittest` and `coverage`. I&#39;m only currently testing a small proportion, but I am trying to work out the code coverage

I run my tests and get the coverage using the following

    python -m unittest discover -s tests/
    coverage run -m unittest discover -s tests/
    coverage report -m

The problem I&#39;m having is that `coverage` is telling I have 44% code coverage and is only counting the files that:

1. were tested in the unit tests (i.e., all the files that were not tested are missing and not in the overall coverage)
 
2. were in the libraries in the virtual environment and code coverage of the actual tests too. Surely it should not be including the actual tests in the results?

Furthermore, it says the files that are actually tested in these unit tests only have the first few lines tested (which are in most cases the import statements)

How do I get a more realistic code coverage or is this how it is meant to be?

How do I make coverage include not tested files?

I&#39;ve just started using [Coverage.py](http://coverage.readthedocs.org/en/latest/index.html) module and so decided to make a simple test to check how it works.

**Sample.py**

    def sum(num1, num2):
        return num1 + num2


    def sum_only_positive(num1, num2):
        if num1 &gt; 0 and num2 &gt; 0:
            return num1 + num2
        else:
            return None

**test.py**  

    from sample import sum, sum_only_positive

    def test_sum():
        assert sum(5, 5) == 10

    def test_sum_positive_ok():
        assert sum_only_positive(2, 2) == 4

    def test_sum_positive_fail():
        assert sum_only_positive(-1, 2) is None

As you see, all my code is covered with tests and py.test says all of them pass. I expect Coverage.py to show 100% coverage. Well, no.

[![Coverage.py results][1]][1]

Well, Coverage.py may not see test.py file, so I copied test functions to `sample.py` file and ran Coverage again:  
[![enter image description here][2]][2]

Then I added this block of code:

    if __name__ == &quot;__main__&quot;:
        print(sum(2, 4))
        print(sum_only_positive(2, 4))
        print(sum_only_positive(-1, 3))

and removed all test functions. After that, Coverage.py shows 100%:

[![enter image description here][3]][3]

Why is it so? Shouldn&#39;t Coverage.py show code test coverage, not just execution coverage? I&#39;ve read an official [F.A.Q.](http://coverage.readthedocs.org/en/latest/faq.html) for Coverage.py, but can&#39;t find the solution.  
Since many SO users are familiar with code testing and code coverage, I hope you can tell me, where am I mistaken.

*I have just one thought here: Coverage.py may simply watch which lines of code aren&#39;t executed so I should write tests for those lines. But there&#39;re lines which are executed already but aren&#39;t covered with tests so Coverage.py will fail here.*


  [1]: http://i.stack.imgur.com/bA2fO.png
  [2]: http://i.stack.imgur.com/ZM4dG.png
  [3]: http://i.stack.imgur.com/MmMqf.png

How to properly use coverage.py in Python?

I am trying to find the coverage using coverage module for a django project but gets 
```
Coverage.py warning: No data was collected. (no-data-collected)
```
My project folder has src and tests folders.

When I run 
```
coverage run -m pytest &amp;&amp; coverage report
```
It produces a report with 100% coverage with the list of files inside the tests folder.
Whereas when I run
```
coverage run --source=src -m pytest &amp;&amp; coverage report
```
it says 
```
Coverage.py warning: No data was collected. (no-data-collected)
No data to report.
```
When I try to give the `source=src` or `include=src` in the `.coveragerc` also the same warning occurs. The tests passes for all the above cases.

I want the coverage of the src folder.
Is it because I am missing some path setting?

Coverage.py warning: No data was collected. (no-data-collected)

I am new to coverage and ran into a strange problem. My coverage is taking my virtual environment site packages into account.
Here is the output of the coverage run:

    coverage run test.py
    ....................
    ----------------------------------------------------------------------
    Ran 20 tests in 0.060s
    
    OK
    (atcatalog)- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -jmfrank63@fullstack-audio-text-catalog:~/workspace (git master)       [19:58:45]
    $ coverage report
    Name                                                                              Stmts   Miss  Cover
    -----------------------------------------------------------------------------------------------------
    /home/ubuntu/Envs/atcatalog/lib/python2.7/site-packages/flask/__init__               18      0   100%
    /home/ubuntu/Envs/atcatalog/lib/python2.7/site-packages/flask/_compat                38     20    47%
    /home/ubuntu/Envs/atcatalog/lib/python2.7/site-packages/flask/app                   528    255    52%
    /home/ubuntu/Envs/atcatalog/lib/python2.7/site-packages/flask/blueprints            156    118    24%
                                 .
                                 .
                                 .
    /home/ubuntu/Envs/atcatalog/lib/python2.7/site-packages/werkzeug/urls               412    215    48%
    /home/ubuntu/Envs/atcatalog/lib/python2.7/site-packages/werkzeug/utils              242    175    28%
    /home/ubuntu/Envs/atcatalog/lib/python2.7/site-packages/werkzeug/wrappers           568    298    48%
    /home/ubuntu/Envs/atcatalog/lib/python2.7/site-packages/werkzeug/wsgi               448    352    21%
    atcatalog/__init__                                                                    7      0   100%
    atcatalog/views/__init__                                                              0      0   100%
    atcatalog/views/publang                                                               7      0   100%
    atcatalog/views/pubtext                                                               1      0   100%
    atcatalog/views/userlang                                                             13      0   100%
    atcatalog/views/users                                                                 5      0   100%
    atcatalog/views/usertext                                                             14      0   100%
    test                                                                                120      0   100%
    -----------------------------------------------------------------------------------------------------
    TOTAL                                                                             12530   8044    36%
    (atcatalog)- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -jmfrank63@fullstack-audio-text-catalog:~/workspace (git master)       [19:58:55]

Here is the structure of my project directory which resides under home:

    workspace/
    ├── README.md
    ├── atcatalog
    │&#160;&#160; ├── __init__.py
    │&#160;&#160; ├── __init__.pyc
    │&#160;&#160; ├── static
    │&#160;&#160; ├── templates
    │&#160;&#160; └── views
    │&#160;&#160;     ├── __init__.py
    │&#160;&#160;     ├── __init__.pyc
    │&#160;&#160;     ├── publang.py
    │&#160;&#160;     ├── publang.pyc
    │&#160;&#160;     ├── pubtext.py
    │&#160;&#160;     ├── pubtext.pyc
    │&#160;&#160;     ├── userlang.py
    │&#160;&#160;     ├── userlang.pyc
    │&#160;&#160;     ├── users.py
    │&#160;&#160;     ├── users.pyc
    │&#160;&#160;     ├── usertext.py
    │&#160;&#160;     └── usertext.pyc
    ├── requirements.txt
    ├── run.py
    └── test.py


I had the virtual environment at first inside the project directory and now moved it out to ~/Envs with virtualenvwrapper, but the problem persisted.
run.py and test.py are not special in any way, they both import app from atcatalog.
I also tried to find ways to omit the virtual environment directory, but google gave no answer (surprisingly).
I don&#39;t think it is the purpose of coverage to test already well tested site-packages. So I would exclude them from the run.

How can I accomplish to avoid coverage having testing my site-packages?



Content Type	Original Author	Original Content on Stackoverflow
Question	doremi	View Question on Stackoverflow
Solution 1 - Python	jkozera	View Answer on Stackoverflow
Solution 2 - Python	Marek Olszewski	View Answer on Stackoverflow

How to Fix Python Nose: Coverage not available: unable to import coverage module

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

Append a single character to a string or char array in java?

In Rails when a resource create action fails and calls render :new, why must the URL change to the resource's index url?

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