Try removing (or renaming) the file `no-global-site-packages.txt` in your `Lib` folder under your virtual environment.

Where **venv** is the name of your virtual environment, and **python3.4** corresponds to whichever version of python involved, for example:

    $ rm venv/lib/python3.4/no-global-site-packages.txt

And if you change your mind and want to put it back:

    $ touch venv/lib/python3.4/no-global-site-packages.txt

**Note:** If you don&#39;t see the above file, then you have a newer version of virtualenv. You&#39;ll want to follow [this answer][1] instead


  [1]: https://stackoverflow.com/a/58513801/21539

At least for Python 3.5.2, there is `pyvenv.cfg` file in the root of virtualenv directory. All you need to do is to change `include-system-site-packages` flag from `false` to `true`:

    home = /usr/bin
    include-system-site-packages = false  # &lt;- change this to &quot;true&quot;
    version = 3.5.2

Go to your venv folder and open `pyvenv.cfg`. (E.g. if your virtual environment is called `myenv` then the file will be located at `myenv\pyvenv.cfg`)

You&#39;ll see a boolean setting called `include-system-site-packages`

Set that setting to `true` to use global packages

If you want to disable using global packages, just set that setting to `false` instead.

When using [virtualenvwrapper](https://bitbucket.org/dhellmann/virtualenvwrapper) to manage virtualenvs, you can use the shell function `toggleglobalsitepackages` to switch between using and not using site packages.

Try adding a symlink between `/virtualenv_root/lib/` and `/path/to/desired/site-packages/`

Where &#39;myvenv&#39; is the name of your virtual environment, and python3.8, like mine, for example, all you need to do in command line is:
````
$ python3 -m venv --system-site-packages myvenv
````

I came across some unexpected behavior when passing a large millisecond value to `setTimeout()`. For instance,

    setTimeout(some_callback, Number.MAX_VALUE);

and

    setTimeout(some_callback, Infinity);

both cause `some_callback` to be run almost immediately, as if I&#39;d passed `0` instead of a large number as the delay.

Why does this happen?

Why does setTimeout() &quot;break&quot; for large millisecond delay values?

I have this code


    $vad = 1.1;
    
    print gettype($vad);
    
    var_dump($vad);

this will output:

    double
    float(1.1) 

So it is double or float in php?




Difference between float and double in php?

I have created a virtualenv using the `--no-site-packages` option and installed lots of libraries. Now I would like to revert the `--no-site-packages` option and use also the global packages.

Can I do that without recreating the virtualenv?

**More precisely:**

I wonder what *exactly* happens when creating a virtualenv using the `--no-site-packages` option as opposed to not using that option.

If I know what happens then I can figure out how to undo it.

Revert the `--no-site-packages` option with virtualenv

I have created a virtualenv using the <code>--no-site-packages</code> option and installed lots of libraries. Now I would like to revert the <code>--no-site-packages</code> option and use also the global packages.
Can I do that without recreating the virtualenv?
More precisely:
I wonder what exactly happens when creating a virtualenv using the <code>--no-site-packages</code> option as opposed to not using that option.
If I know what happens then I can figure out how to undo it.

I completed my first proper project in Python and now my task is to write tests for it.

Since this is the first time I did a project, this is the first time I would be writing tests for it.

The question is, *how* do I start? I have absolutely no idea. Can anyone point me to some documentation/ tutorial/ link/ book that I can use to start with writing tests (and I guess unit testing in particular)

Any advice will be welcomed on this topic. 

Writing unit tests in Python: How do I start?

I have a list with numeric strings, like so:

    numbers = [&#39;1&#39;, &#39;5&#39;, &#39;10&#39;, &#39;8&#39;];

I would like to convert every list element to integer, so it would look like this:

    numbers = [1, 5, 10, 8];

I could do it using a loop, like so:

    new_numbers = [];
    for n in numbers:
        new_numbers.append(int(n));
    numbers = new_numbers;

Does it have to be so ugly? I&#39;m sure there is a more pythonic way to do this in a one line of code. Please help me out.

Call int() function on every list element?

I have the following code:

    import matplotlib.pyplot as plt

    cdict = {
      &#39;red&#39;  :  ( (0.0, 0.25, .25), (0.02, .59, .59), (1., 1., 1.)),
      &#39;green&#39;:  ( (0.0, 0.0, 0.0), (0.02, .45, .45), (1., .97, .97)),
      &#39;blue&#39; :  ( (0.0, 1.0, 1.0), (0.02, .75, .75), (1., 0.45, 0.45))
    }
 
    cm = m.colors.LinearSegmentedColormap(&#39;my_colormap&#39;, cdict, 1024)
 
    plt.clf()
    plt.pcolor(X, Y, v, cmap=cm)
    plt.loglog()
    plt.xlabel(&#39;X Axis&#39;)
    plt.ylabel(&#39;Y Axis&#39;)
 
    plt.colorbar()
    plt.show()

So this produces a graph of the values &#39;v&#39; on the axes X vs Y, using the specified colormap. The X and Y axes are perfect, but the colormap spreads between the min and max of v. I would like to force the colormap to range between 0 and 1.

I thought of using:

    plt.axis(...)

To set the ranges of the axes, but this only takes arguments for the min and max of X and Y, not the colormap.

**Edit:**

For clarity, let&#39;s say I have one graph whose values range (0 ... 0.3), and another graph whose values (0.2 ... 0.8).

In both graphs, I will want the range of the colorbar to be (0 ... 1). In both graphs, I want this range of colour to be identical using the full range of cdict above (so 0.25 in both graphs will be the same colour). In the first graph, all colours between 0.3 and 1.0 won&#39;t feature in the graph, but will in the colourbar key at the side. In the other, all colours between 0 and 0.2, and between 0.8 and 1 will not feature in the graph, but will in the colourbar at the side.

Set Colorbar Range in matplotlib

compiling vim with python support

I use [cProfile][1] now but I find it tedious to write pstats code just to query the statistics data.

I&#39;m looking for a visual tool that shows me what my Python code is doing in terms of CPU time and memory allocation.

Some examples from the Java world are [visualvm][2] and [JProfiler][3].

- Does something like this exist?
- Is there an IDE that does this?
- Would [dtrace][4] help?

I know about [KCachegrind][5] for Linux, but I would prefer something that I can run on Windows/Mac without installing KDE.


  [1]: http://docs.python.org/library/profile.html
  [2]: https://visualvm.dev.java.net/features.html
  [3]: http://www.ej-technologies.com/products/jprofiler/top10.html
  [4]: http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/InstrumentsUserGuide/ViewingandAnalyzingData/ViewingandAnalyzingData.html#//apple_ref/doc/uid/TP40004652-CH5-SW2
  [5]: https://stackoverflow.com/questions/1896032/using-cprofile-results-with-kcachegrind

Is there a visual profiler for Python?

I&#39;ve searched the wiki modules page, but I can&#39;t find anything similar to virtualenv (python) or rvm. 

Anyone here separates node.js in their own env? I really don&#39;t like to install npm system-wide.

Is there a virtual environment for node.js?

I want to build html docs using a virtualenv instead of the native environment on my machine. 

I&#39;ve entered the virtualenv but when I run `make html` I get errors saying the module can&#39;t be imported - I *know* the errors are due to the module being unavailable in my native environment. 
How can I specify which environment should be used when searching for docs (eg the virtualenv)?

How to make sphinx look for modules in virtualenv while building html?

I want to set up a crontab to run a Python script.

Say the script is something like:

    #!/usr/bin/python
    print &quot;hello world&quot;

Is there a way I could specify a virtualenv for that Python script to run in? In shell I&#39;d just do:

    ~$ workon myenv

Is there something equivalent I could do in crontab to activate a virtualenv?

How to set virtualenv for a crontab?

How do I repeat the last command? The usual keys: Up, Ctrl+Up, Alt-p don&#39;t work. They produce nonsensical characters.

    (ve)[kakarukeys@localhost ve]$ python
    Python 2.6.6 (r266:84292, Nov 15 2010, 21:48:32) 
    [GCC 4.4.4 20100630 (Red Hat 4.4.4-10)] on linux2
    Type &quot;help&quot;, &quot;copyright&quot;, &quot;credits&quot; or &quot;license&quot; for more information.
    &gt;&gt;&gt; print &quot;hello world&quot;
    hello world
    &gt;&gt;&gt; ^[[A
      File &quot;&lt;stdin&gt;&quot;, line 1
        ^
    SyntaxError: invalid syntax
    &gt;&gt;&gt; ^[[1;5A
      File &quot;&lt;stdin&gt;&quot;, line 1
        [1;5A
        ^
    SyntaxError: invalid syntax
    &gt;&gt;&gt; ^[p
      File &quot;&lt;stdin&gt;&quot;, line 1
        p
        ^
    SyntaxError: invalid syntax
    &gt;&gt;&gt; 


How to repeat last command in python interpreter shell?

## Short Question ##

* What is the proper way to install [`pip`][pip], [`virtualenv`][virtualenv], and [`distribute`][distribute]?

## Background ##

In [my answer][so-answer] to [SO question 4314376][so-question], I recommended using `ez_setup` so that you could then install `pip` and `virtualenv` as follows:

    curl -O http://peak.telecommunity.com/dist/ez_setup.py
    sudo python ez_setup.py
    sudo easy_install pip
    sudo pip install virtualenv

I originally pulled these instructions from Jesse Noller&#39;s blog post [So you want to use Python on the Mac?][noller]. I like the idea of keeping a clean global site-packages directory, so the only other packages I install there are  [`virtualenvwrapper`][virtualenvwrapper] and [`distribute`][distribute]. (I recently added [`distribute`][distribute] to my toolbox because of [this Python public service announcement][public]. To install these two packages, I used:

    sudo pip install virtualenvwrapper
    curl -O http://python-distribute.org/distribute_setup.py
    sudo python distribute_setup.py

## No more setuptools and easy_install ##

To really follow [that Python public service announcement][public], on a fresh Python install, I would do the following:

    curl -O http://python-distribute.org/distribute_setup.py
    sudo python distribute_setup.py
    sudo easy_install pip
    sudo pip install virtualenv
    sudo pip install virtualenvwrapper

## Glyph&#39;s Rebuke ##

In a comment to [my answer][so-answer] to [SO question 4314376][so-question], SO user [Glyph][] stated:

&gt; NO. NEVER EVER do `sudo python setup.py install` whatever. Write a ~/.pydistutils.cfg that puts your pip installation into ~/.local or something. Especially files named `ez_setup.py` tend to suck down newer versions of things like setuptools and easy_install, which can potentially break other things on your operating system.

## Back to the short question ##

So [Glyph&#39;s response][so-answer] leads me to my original question:

* What is the proper way to install [`pip`][pip], [`virtualenv`][virtualenv], and [`distribute`][distribute]?


[distribute]: http://packages.python.org/distribute/
[ez_setup]: http://peak.telecommunity.com/DevCenter/EasyInstall

[glyph]: https://stackoverflow.com/users/13564/glyph
[noller]: http://jessenoller.com/2009/03/16/so-you-want-to-use-python-on-the-mac/
[pip]: http://pip.readthedocs.org
[public]: http://s3.pixane.com/pip_distribute.png
[so-answer]:  https://stackoverflow.com/questions/4314376/python-egg-file/4314446#4314446
[so-question]: https://stackoverflow.com/questions/4314376/python-egg-file

[virtualenv]: http://virtualenv.openplans.org/
[virtualenvwrapper]: http://www.doughellmann.com/projects/virtualenvwrapper/


Content Type	Original Author	Original Content on Stackoverflow
Question	Olivier Verdier	View Question on Stackoverflow
Solution 1 - Python	ars	View Answer on Stackoverflow
Solution 2 - Python	kotrfa	View Answer on Stackoverflow
Solution 3 - Python	Zain Rizvi	View Answer on Stackoverflow
Solution 4 - Python	Adaephon	View Answer on Stackoverflow
Solution 5 - Python	Tim McNamara	View Answer on Stackoverflow
Solution 6 - Python	alexzorgo	View Answer on Stackoverflow

Revert the `--no-site-packages` option with virtualenv

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

Solution 3 - Python

Solution 4 - Python

Solution 5 - Python

Solution 6 - Python

Difference between float and double in php?

Why does setTimeout() "break" for large millisecond delay values?

Attributions