You may add something that closes/quits the windows you invoke.

For example you could close the figure `self.scene.mayavi_scene` using function [`mayavi.mlab.close`](https://docs.enthought.com/mayavi/mayavi/auto/mlab_figure.html#close).

When I try to initialize Firebase Cloud Firestore, I ran into the following error: 

&gt; Uncaught TypeError: __WEBPACK_IMPORTED_MODULE_0_firebase__.firestore is not a function

I installed firebase with `npm install firebase --save` previously.

    import * as firebase from &#39;firebase&#39;;
    import router from &#39;../router&#39;;

    const config = {
            apiKey: &quot;a&quot;,
            authDomain: &quot;a&quot;,
            databaseURL: &quot;a&quot;,
            projectId: &quot;a&quot;,
            storageBucket: &quot;a&quot;,
            messagingSenderId: &quot;a&quot;
    };
    if(!firebase.apps.length){
      firebase.initializeApp(config);
      let firestore = firebase.firestore();
    }



firebase.firestore() is not a function when trying to initialize Cloud Firestore

I&#39;m trying to set up a simple systemd timer to run a bash script every day at midnight.

```systemctl --user status backup.service``` fails and logs the following:

    backup.service: Failed at step EXEC spawning /home/user/.scripts/backup.sh: No such file or directory.

    backup.service: Main process exited, code=exited, status=203/EXEC
    Failed to start backup.
    backup.service: Unit entered failed state.
    backup.service: Failed with result &#39;exit-code&#39;.

I&#39;m lost, since the files and directories exist. The script is executable and, just to check, I&#39;ve even set permissions to 777.

Some background:

The ```backup.timer``` and ```backup.service``` unit files are located in ```/home/user/.config/systemd/user```.

```backup.timer``` is loaded and active, and currently waiting for midnight.

Here&#39;s what it looks like:

    [Unit]
    Description=Runs backup at 0000

    [Timer]
    OnCalendar=daily
    Unit=backup.service

    [Install]
    WantedBy=multi-user.target

Here&#39;s ```backup.service```:

    [Unit]
    Description=backup

    [Service]
    Type=oneshot
    ExecStart=/home/user/.scripts/backup.sh

    [Install]
    WantedBy=multi-user.target

And lastly, this is a paraphrase of ```backup.sh```:
    
    #!/usr/env/bin bash

    rsync -a --delete --quiet /home/user/directory/ /mnt/drive/directory-backup/

The script runs fine if I execute it myself.

Not sure if it matters, but I use ```fish``` as my shell (started from .bashrc).

I&#39;m happy to post the full script if that&#39;s helpful.

Fixing a systemd service 203/EXEC failure (no such file or directory)

I&#39;m trying to create a GUI in TraitsUI that includes two Mayavi figures. I have implemented these figures as per the [multiple engines example][1] in the Mayavi documentation.

However, when I add a colorbar to one of the figures and run the GUI script it sometimes opens a blank Mayavi Scene Editor window in addition to the desired TraitsUI window. This blank window doesn&#39;t always appear, never on the first run after restarting the python kernel, and sometimes only after running the script a few times in succession and closing the windows that appear each time.

Running the much-reduced code below produces the same behaviour, and removing the `mlab.colorbar(s)` line stops the problem. How can I get a colorbar without opening blank windows? There doesn&#39;t seem to be an obvious way to assign a colorbar to a specific figure as for the surface plot. I am running Python 3.5 on Windows 7 (but get the same issues on Ubuntu).

    from traits.api import HasTraits, Instance, on_trait_change
    from traitsui.api import View, Item
    import numpy as np
    
    from mayavi.core.api import Engine
    from mayavi.core.ui.api import SceneEditor, MlabSceneModel
    from mayavi import mlab
    
    #Generate a test surface to display
    def test_surf():
        x, y = np.mgrid[-7.:7.05:0.1, -5.:5.05:0.05]
        z = np.sin(x + y) + np.sin(2 * x - y) + np.cos(3 * x + 4 * y)
        return x, y, z        
        
    class MyApp(HasTraits):
        
        #Create a mayavi scene with a specified engine
        engine = Instance(Engine, ())
        scene = Instance(MlabSceneModel)
        def _scene_default(self):
            self.engine.start()
            return MlabSceneModel(engine=self.engine)         
        
        #Plot the surface when the scene is activated
        @on_trait_change(&#39;scene.activated&#39;)
        def populate_scene(self):
            s = mlab.surf(*test_surf(), figure=self.scene.mayavi_scene)
            mlab.colorbar(s)
    
        view = View(Item(&#39;scene&#39;, editor=SceneEditor()))
    
    if __name__ == &#39;__main__&#39;:
        MyApp().configure_traits()

  [1]: http://docs.enthought.com/mayavi/mayavi/auto/example_multiple_engines.html

Mayavi colorbar in TraitsUI creating blank window

I'm trying to create a GUI in TraitsUI that includes two Mayavi figures. I have implemented these figures as per the <a href="http://docs.enthought.com/mayavi/mayavi/auto/example_multiple_engines.html" target="_blank" rel="noopener noreferrer">multiple engines example</a> in the Mayavi documentation.
However, when I add a colorbar to one of the figures and run the GUI script it sometimes opens a blank Mayavi Scene Editor window in addition to the desired TraitsUI window. This blank window doesn't always appear, never on the first run after restarting the python kernel, and sometimes only after running the script a few times in succession and closing the windows that appear each time.
Running the much-reduced code below produces the same behaviour, and removing the <code>mlab.colorbar(s)</code> line stops the problem. How can I get a colorbar without opening blank windows? There doesn't seem to be an obvious way to assign a colorbar to a specific figure as for the surface plot. I am running Python 3.5 on Windows 7 (but get the same issues on Ubuntu).
<pre><code class="hljs language-python">from traits.api import HasTraits, Instance, on_trait_change
from traitsui.api import View, Item
import numpy as np

from mayavi.core.api import Engine
from mayavi.core.ui.api import SceneEditor, MlabSceneModel
from mayavi import mlab

#Generate a test surface to display
def test_surf():
 x, y = np.mgrid[-7.:7.05:0.1, -5.:5.05:0.05]
 z = np.sin(x + y) + np.sin(2 * x - y) + np.cos(3 * x + 4 * y)
 return x, y, z 
 
class MyApp(HasTraits):
 
 #Create a mayavi scene with a specified engine
 engine = Instance(Engine, ())
 scene = Instance(MlabSceneModel)
 def _scene_default(self):
 self.engine.start()
 return MlabSceneModel(engine=self.engine) 
 
 #Plot the surface when the scene is activated
 @on_trait_change('scene.activated')
 def populate_scene(self):
 s = mlab.surf(*test_surf(), figure=self.scene.mayavi_scene)
 mlab.colorbar(s)

 view = View(Item('scene', editor=SceneEditor()))

if __name__ == '__main__':
 MyApp().configure_traits()
</code></pre>

Using the Python function syntax `def f(**kwargs)`, in the function a keyword argument dictionary `kwargs` is created, and dictionaries are mutable, so the question is, if I modify the `kwargs` dictionary, is it possible that I might have some effect outside the scope of my function?

From my understanding of how dictionary unpacking and keyword argument packing works, I don&#39;t see any reason to believe it might be unsafe, and it seems to me that there is no danger of this in Python 3.6:

    def f(**kwargs):
        kwargs[&#39;demo&#39;] = 9
    
    if __name__ == &#39;__main__&#39;:
        demo = 4
        f(demo=demo)
        print(demo)     # 4
        
        kwargs = {}
        f(**kwargs)
        print(kwargs)   # {}
        
        kwargs[&#39;demo&#39;] = 4
        f(**kwargs)
        print(kwargs)    # {&#39;demo&#39;: 4}

However, is this implementation-specific, or is it part of the Python spec? Am I overlooking any situation or implementation where (barring modifications to arguments which are *themselves* mutable, like `kwargs[&#39;somelist&#39;].append(3)`) this sort of modification might be a problem?

Is it always safe to modify the `**kwargs` dictionary?

Problem
==============
Say you have two lists `A = [a_1, a_2, ..., a_n]` and `B = [b_1, b_2, ..., b_n]` of integers. We say `A` is **potentially-divisible** by `B` if there is a permutation of `B` that makes `a_i` divisible by `b_i` for all `i`. The problem is then: is it possible to reorder (i.e. permute) `B` so that `a_i` is divisible by `b_i` for all `i`?
For example, if you have

    A = [6, 12, 8]
    B = [3, 4, 6]

Then the answer would be `True`, as `B` can be reordered to be `B = [3, 6, 4]` and then we would have that `a_1 / b_1 = 2 `, `a_2 / b_2 = 2 `, and `a_3 / b_3 = 2 `, all of which are integers, so `A` is potentially-divisible by `B`.

As an example which should output `False`, we could have:

    A = [10, 12, 6, 5, 21, 25]
    B = [2, 7, 5, 3, 12, 3]

The reason this is `False` is that we can&#39;t reorder `B` as 25 and 5 are in `A`, but the only divisor in `B` would be 5, so one would be left out.

Approach
==============

Obviously the straightforward approach would be to get all the permutations of `B` and see if one would satisfy **potential-divisibility**, something along the lines of:

    import itertools
    def is_potentially_divisible(A, B):
      perms = itertools.permutations(B)
      divisible = lambda ls: all( x % y == 0 for x, y in zip(A, ls))
      return any(divisible(perm) for perm in perms)

Question
==============
What is the fastest way to know if a list is potentially-divisible by another list? Any thoughts? I was thinking if there&#39;s is a clever way to do this with **primes**, but I couldn&#39;t come up with a solution.

Much appreciated!


----------

*Edit*: It&#39;s probably irrelevant to most of you, but for the sake of completeness, I&#39;ll explain my motivation. In Group Theory there is a conjecture on finite simple groups on whether or not there is a bijection from irreducible characters and conjugacy classes of the group such that every character degree divides the corresponding class size. For example, for *U6(4)* [here are what `A` and `B` would look like.][1] Pretty big lists, mind you!


  [1]: https://gist.github.com/nachonavarro/cffc80ee2cf27cf6535d29b2dbfc9913

Is a list (potentially) divisible by another?

I have DataFrame:

    	time_diff	avg_trips
    0	0.450000	1.0
    1	0.483333	1.0
    2	0.500000	1.0
    3	0.516667	1.0
    4	0.533333	2.0

I want to get 1st quartile, 3rd quartile and median for the column `time_diff`. To obtain median, I use `np.median(df[&quot;time_diff&quot;].values)`.

How can I calculate quartiles?

How to calculate 1st and 3rd quartiles?

I am using Python 3.6. When I try to install &quot;modules&quot; using `pip3`, I face this issue:

    pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available

pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available

I&#39;m trying to write PEP-8 compliant code for a domestic project and I have a line with an f-string that is more than 80 characters long

![](https://i.stack.imgur.com/Wn6Jh.png) - the solid thin line near the dot at self.text is the 80 char mark.

I&#39;m trying to split it into different lines in the most *pythonic* way but the only aswer that actually works is an error for my linter

*Working Code:*

    def __str__(self):
        return f&#39;{self.date} - {self.time},\nTags:&#39; + \
        f&#39; {self.tags},\nText: {self.text}&#39;


*Output:*

    2017-08-30 - 17:58:08.307055,
    Tags: test tag,
    Text: test text

The linter thinks that i&#39;m not respecting E122 from PEP-8, is there a way to get the string right and the code compliant?

Multiline f-string in Python

Whats the difference between `ThreadPool` and `Pool` in `multiprocessing` module.  When I try my code out, this is the main difference I see:

    from multiprocessing import Pool
    import os, time
    
    print(&quot;hi outside of main()&quot;)
    
    def hello(x):
        print(&quot;inside hello()&quot;)
        print(&quot;Proccess id: &quot;, os.getpid())
        time.sleep(3)
        return x*x
    
    if __name__ == &quot;__main__&quot;:
        p = Pool(5)
        pool_output = p.map(hello, range(3))
    
        print(pool_output)

I see the following output:

    hi outside of main()
    hi outside of main()
    hi outside of main()
    hi outside of main()
    hi outside of main()
    hi outside of main()
    inside hello()
    Proccess id:  13268
    inside hello()
    Proccess id:  11104
    inside hello()
    Proccess id:  13064
    [0, 1, 4]

With &quot;ThreadPool&quot;:

    from multiprocessing.pool import ThreadPool
    import os, time
    
    print(&quot;hi outside of main()&quot;)
    
    def hello(x):
        print(&quot;inside hello()&quot;)
        print(&quot;Proccess id: &quot;, os.getpid())
        time.sleep(3)
        return x*x
    
    if __name__ == &quot;__main__&quot;:
        p = ThreadPool(5)
        pool_output = p.map(hello, range(3))
    
        print(pool_output)

I see the following output:

    hi outside of main()
    inside hello()
    inside hello()
    Proccess id:  15204
    Proccess id:  15204
    inside hello()
    Proccess id:  15204
    [0, 1, 4]

My questions are:

 - why is the “outside \__main\__()” run each time in the `Pool`?


 - `multiprocessing.pool.ThreadPool` doesn&#39;t spawn new processes?  It just creates new threads?  

 - If so whats the difference between using `multiprocessing.pool.ThreadPool` as opposed to just `threading` module?  

I don&#39;t see any official documentation for `ThreadPool` anywhere, can someone help me out where I can find it?

What&#39;s the difference between ThreadPool vs Pool in the multiprocessing module?

Might look like an already answered question, actually [here][1] you have the same problem (kind of) i had. My problem is, it&#39;s just a trick, one line, no explanation (and still it&#39;s different but the solution given works, and that&#39;s part of my problem).
Here&#39;s my project structure, simplified:

    manage.py
    compfactu/---settings.py
              |--__init__.py
              |--core/--------__init__.py
                             |-apps.py  

So here is how I added my app in ```INSTALLED_APPS```:

**apps.py**

    from django.apps import AppConfig
    
    
    class CoreConfig(AppConfig):
        name = &#39;core&#39;


**settings.py**

    INSTALLED_APPS = [ 
        ...
        #compfactu modules
        &#39;compfactu.core.apps.CoreConfig&#39;,
    ]
As I read the django 1.11 documentation, and I quote :
&gt; New applications should avoid default_app_config. Instead they should require the dotted path to the appropriate AppConfig subclass to be configured explicitly in INSTALLED_APPS.

Well nice, it&#39;s a new application so i should do that : but i&#39;m getting an error. And it&#39;s not a problem of pythonpath, cause i just opened a python shell and I can do ```from compfactu.core.apps import CoreConfig``` with no problem (print the sys.path too, everything&#39;s fine).

But I have this error, here&#39;s a full traceback:

    Traceback (most recent call last):
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/apps/config.py&quot;, line 147, in create
        app_module = import_module(app_name)
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/importlib/__init__.py&quot;, line 126, in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
      File &quot;&lt;frozen importlib._bootstrap&gt;&quot;, line 986, in _gcd_import
      File &quot;&lt;frozen importlib._bootstrap&gt;&quot;, line 969, in _find_and_load
      File &quot;&lt;frozen importlib._bootstrap&gt;&quot;, line 956, in _find_and_load_unlocked
    ImportError: No module named &#39;core&#39;
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/utils/autoreload.py&quot;, line 228, in wrapper
        fn(*args, **kwargs)
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/core/management/commands/runserver.py&quot;, line 117, in inner_run
        autoreload.raise_last_exception()
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/utils/autoreload.py&quot;, line 251, in raise_last_exception
        six.reraise(*_exception)
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/utils/six.py&quot;, line 685, in reraise
        raise value.with_traceback(tb)
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/utils/autoreload.py&quot;, line 228, in wrapper
        fn(*args, **kwargs)
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/__init__.py&quot;, line 27, in setup
        apps.populate(settings.INSTALLED_APPS)
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/apps/registry.py&quot;, line 85, in populate
        app_config = AppConfig.create(entry)
      File &quot;/home/jbjaillet/Projets/venvcompfactu/lib/python3.5/site-packages/django/apps/config.py&quot;, line 151, in create
        app_name, mod_path, cls_name,
    django.core.exceptions.ImproperlyConfigured: Cannot import &#39;core&#39;. Check that &#39;compfactu.core.apps.CoreConfig.name&#39; is correct.

And from there, all files and class have been generated by django (manage.py startapp).
And when I actually do what&#39;s told in the question I linked above, doing like :

    INSTALLED_APPS = [ 
        ...
        #compfactu modules
        &#39;compfactu.core&#39;,
    ]

 it works ! And I don&#39;t get that point ! Reading the doc (part i&#39;ve just quoted), it SHOULD NOT work (noting that I don&#39;t have a ```default_app_config``` in my ```__init__.py```.

So, as the question where I found the &quot;trick&quot; but no explanation, I&#39;m here asking why it works this way when it shouldn&#39;t, and why the solution in the official doc doesn&#39;t work?

Thank you in advance for you time.

  [1]: https://stackoverflow.com/questions/43621259/django-project-restructure-cant-import-app

Django : Can&#39;t import &#39;module&#39;. Check that module AppConfig.name is correct

I&#39;m new to Python (and to programming as well) and, although well documented, I cannot understand what exactly means the -m directive (precisely in the creation of a virtual environment: `python3 -m venv my_env`. 

As far as I can read from the documentation, it stands for &quot;run library module as a script&quot;: it is in fact this concept that I cannot figure out and what is the difference in running the command without the `-m`.

Moreover, it this a characteristic of Python 3?

What does it mean to &quot;run library module as a script&quot; with the &quot;-m&quot; option?

I&#39;m new to Python development and attempting to use pipenv. I ran the command `pip install pipenv`, which ran successfully:

    ...
    Successfully built pipenv pathlib shutilwhich pythonz-bd virtualenv-clone
    Installing collected packages: virtualenv, pathlib, shutilwhich, backports.shutil-get-terminal-size, pythonz-bd, virtualenv-clone, pew, first, six, click, pip-tools, certifi, chardet, idna, urllib3, requests, pipenv
    ...

However, when I run the command `pipenv install` in a fresh root project directory I receive the following message: `-bash: pipenv: command not found`. I suspect that I might need to modify my .bashrc, but I&#39;m unclear about what to add to the file or if modification is even necessary.


Pipenv: Command Not Found

I am trying to prettify the json format but i am getting this error:

    import requests as tt
    from bs4 import BeautifulSoup
    import json
    
    get_url=tt.get(&quot;https://in.pinterest.com/search/pins/?rs=ac&amp;len=2&amp;q=batman%20motivation&amp;eq=batman%20moti&amp;etslf=5839&amp;term_meta[]=batman%7Cautocomplete%7Cundefined&amp;term_meta[]=motivation%7Cautocomplete%7Cundefined&quot;)
    soup=BeautifulSoup(get_url.text,&quot;html.parser&quot;)
    
    select_css=soup.select(&quot;script#jsInit1&quot;)[0]
    for i in select_css:
        print(json.dump(json.loads(i),indent=4,sort_keys=True))

Basically i want to extract this type of element :

    &#39;orig&#39;: {&#39;width&#39;: 1080, &#39;url&#39;: &#39;&#39;, &#39;height&#39;: 1349},

I know i can do this with 


    select_css.get(&#39;orig&#39;).get(&#39;url&#39;)

But i am not sure is this json element is nested element under any element ? That&#39;s why i am trying to prettify to get idea.


Content Type	Original Author	Original Content on Stackoverflow
Question	Siyh	View Question on Stackoverflow
Solution 1 - Python	Alexander Brockmeier	View Answer on Stackoverflow

Mayavi colorbar in TraitsUI creating blank window

Python Problem Overview

Python Solutions

Solution 1 - Python

Fixing a systemd service 203/EXEC failure (no such file or directory)

firebase.firestore() is not a function when trying to initialize Cloud Firestore

Attributions