&gt; ***WARNING***: Security researches have found [several poisoned packages on PyPI](http://www.nbu.gov.sk/skcsirt-sa-20170909-pypi/index.html), including a package named `urllib`, which will &#39;phone home&#39; when installed. *If you used `pip install urllib` some time after June 2017, remove that package **as soon as possible***.

You can&#39;t, and you don&#39;t need to.

`urllib2` is the name of the library included in Python 2. You can use the [`urllib.request` library](https://docs.python.org/3/library/urllib.request.html#module-urllib.request) included with Python 3, instead. The `urllib.request` library works the same way `urllib2` works in Python 2. Because it is *already included* you don&#39;t need to install it.

If you are following a tutorial that tells you to use `urllib2` then you&#39;ll find you&#39;ll run into more issues. Your tutorial was written for Python 2, not Python 3. Find a different tutorial, or install Python 2.7 and continue your tutorial on that version. You&#39;ll find `urllib2` comes with that version.

Alternatively, install the [`requests` library](https://pypi.python.org/pypi/requests) for a higher-level and easier to use API. It&#39;ll work on both Python 2 and 3.

&gt; In Python 3, `urllib2` was replaced by two in-built modules named `urllib.request` and `urllib.error`

*Adapted from [source](https://docs.python.org/2/library/urllib2.html)*

---

So replace this:

```
import urllib2
```

With this:

```python
import urllib.request as urllib2
```

Acording to the [docs](https://docs.python.org/2/library/urllib2.html):

&gt; **Note** The urllib2 module has been split across several modules in Python 3 named `urllib.request` and `urllib.error`. The 2to3 tool will automatically adapt imports when converting your sources to Python 3. 

So it appears that it is impossible to do what you want but you can use appropriate python3 functions from `urllib.request`.

I&#39;ve installed git on a mac via `brew install git`. When I try to start gitk I get the following error:

    Error in startup script: unknown color name &quot;lime&quot;
        (processing &quot;-fore&quot; option)
        invoked from within
    &quot;$ctext tag conf m2 -fore [lindex $mergecolors 2]&quot;
        (procedure &quot;makewindow&quot; line 347)
        invoked from within
    &quot;makewindow&quot;
        (file &quot;/usr/local/bin/gitk&quot; line 12434)

It appears that my Mac doesn&#39;t have a color named `lime`. 

Can I add a lime color to the environment, or is there a better fix? 

The git version is 2.7.0, and the Mac is running Yosemite 10.10.5

gitk will not start on Mac: unknown color name &quot;lime&quot;

I have been using [ECMAScript&amp;nbsp;6][1] and ECMAScript&amp;nbsp;7 features already (thanks to Babel) in my applications - both mobile and web.

The first step obviously was to ECMAScript&amp;nbsp;6 levels. I learnt many async patterns, the promises (which are really promising), generators (not sure why the * symbol), etc.
Out of these, promises suited my purpose pretty well. And I have been using them in my applications quite a lot.

Here is an example/pseudocode of how I have implemented a basic promise-

    var myPromise = new Promise(
        function (resolve,reject) {
          var x = MyDataStore(myObj);
          resolve(x);
        });

    myPromise.then(
      function (x) {
        init(x);
    });

As time passed, I came across ECMAScript&amp;nbsp;7 features, and one of them being ```ASYNC``` and ```AWAIT``` keywords/functions. These in conjunction do great wonders. I have started to replace some of my promises with ```async &amp; await```. They seem to add great value to programming style.

Again, here is a pseudocode of how my async, await function looks like-

    async function myAsyncFunction (myObj) {
        var x = new MyDataStore(myObj);
        return await x.init();
    }
    var returnVal = await myAsyncFunction(obj);

Keeping the syntax errors (if any) aside, both of them do the exact same thing is what I feel. I have almost been able to replace most of my promises with async,awaits.

Why is async,await needed when promises do a similar job?

Does async,await solve a bigger problem? Or was it just a different solution to callback hell?

As I said earlier, I am able to use promises and async,await to solve the same problem. Is there anything specific that async await solved?

Additional notes:

I have been using async,awaits and promises in my React projects and Node.js modules extensively.
React especially have been an early bird and adopted a lot of ECMAScript&amp;nbsp;6 and ECMAScript&amp;nbsp;7 features.

  [1]: https://en.wikipedia.org/wiki/ECMAScript#6th_Edition_-_ECMAScript_2015


What is the difference between JavaScript promises and async await?

I&#39;m running Python 3.5.1 for Mac. I want to use `urllib2` module. I tried installing it but I was told that it&#39;s been split into `urllib.request` and `urllib.error` for Python 3. 

My command (running from the framework bin directory for now because it&#39;s not in my path):

    sudo ./pip3 install urllib.request

Returns this:

    Could not find a version that satisfies the requirement urllib.request (from versions: )
    No matching distribution found for urllib.request

I got the same error before when I tried to install `urllib2` in one fell swoop.

Need to install urllib2 for Python 3.5.1

I'm running Python 3.5.1 for Mac. I want to use <code>urllib2</code> module. I tried installing it but I was told that it's been split into <code>urllib.request</code> and <code>urllib.error</code> for Python 3.
My command (running from the framework bin directory for now because it's not in my path):
<pre><code class="hljs language-bash">sudo ./pip3 install urllib.request
</code></pre>
Returns this:
<pre><code class="hljs language-css">Could not find a version that satisfies the requirement urllib.request (from versions: )
No matching distribution found for urllib.request
</code></pre>
I got the same error before when I tried to install <code>urllib2</code> in one fell swoop.

I have a directory structure similar to the following

    meta_project
        project1
            __init__.py
            lib
                module.py
                __init__.py
        notebook_folder
            notebook.jpynb

When working in `notebook.jpynb` if I try to use a relative import to access a function `function()` in `module.py` with:

    from ..project1.lib.module import function

I get the following error:

    SystemError                               Traceback (most recent call last)
    &lt;ipython-input-7-6393744d93ab&gt; in &lt;module&gt;()
    ----&gt; 1 from ..project1.lib.module import function
    
    SystemError: Parent module &#39;&#39; not loaded, cannot perform relative import

Is there any way to get this to work using relative imports? 

Note, the notebook server is instantiated at the level of the `meta_project` directory, so it should have access to the information in those files. 

Note, also, that at least as originally intended `project1` wasn&#39;t thought of as a module and therefore does not have an `__init__.py` file, it was just meant as a file-system directory. If the solution to the problem requires treating it as a module and including an `__init__.py` file (even a blank one) that is fine, but doing so is not enough to solve the problem.

I share this directory between machines and relative imports allow me to use the same code everywhere, &amp; I often use notebooks for quick prototyping, so suggestions that involve hacking together absolute paths are unlikely to be helpful.

------------------

Edit: This is unlike https://stackoverflow.com/questions/16981921/relative-imports-in-python-3, which talks about relative imports in Python 3 in general and – in particular – running a script from within a package directory. This has to do with working within a jupyter notebook trying to call a function in a local module in another directory which has both different general and particular aspects. 

Import local function from a module housed in another directory with relative imports in Jupyter Notebook using Python 3

I want to create Postgres database using Python.

    con = psql.connect(dbname=&#39;postgres&#39;,
          user=self.user_name, host=&#39;&#39;,
          password=self.password)

    cur = con.cursor()
    cur.execute(&quot;CREATE DATABASE %s  ;&quot; % self.db_name)

I am getting the following error:

    InternalError: CREATE DATABASE cannot run inside a transaction block
I am using psycopg2 to connect. I don&#39;t understand what&#39;s the problem.
What am I trying to do is to connect to database (Postgres):

    psql -postgres -U UserName
And then create another database:

    create database test;
This is what I usually do and I want to automate this by creating Python script.


Create a Postgres database using python

In the answers to https://stackoverflow.com/questions/21360361/how-to-dynamically-update-a-plot-in-a-loop-in-ipython-notebook-within-one-cell, an example is given of how to dynamically update a plot inside a Jupyter notebook within a Python loop. However, this works by destroying and re-creating the plot on every iteration, and a comment in one of the threads notes that this situation can be improved by using the new-ish `%matplotlib nbagg` magic, which provides an interactive figure embedded in the notebook, rather than a static image.

However, this wonderful new `nbagg` feature seems to be completely undocumented as far as I can tell, and I&#39;m unable to find an example of how to use it to dynamically update a plot. Thus my question is, **how does one efficiently update an existing plot in a Jupyter/Python notebook, using the nbagg backend?** Since dynamically updating plots in matplotlib is a tricky issue in general, a simple working example would be an enormous help. A pointer to any documentation on the topic would also be extremely helpful.

To be clear what I&#39;m asking for: what I want to do is to run some simulation code for a few iterations, then draw a plot of its current state, then run it for a few more iterations, then update the plot to reflect the current state, and so on. So the idea is to draw a plot and then, without any interaction from the user, update the data in the plot without destroying and re-creating the whole thing.

Here is some slightly modified code from the answer to the linked question above, which achieves this by re-drawing the whole figure every time. I want to achieve the same result, but more efficiently using `nbagg`.

    %matplotlib inline
    import time
    import pylab as pl
    from IPython import display
    for i in range(10):
        pl.clf()
        pl.plot(pl.randn(100))
        display.display(pl.gcf())
        display.clear_output(wait=True)
        time.sleep(1.0)

What is the currently correct way to dynamically update plots in Jupyter/iPython?

How can one add a new coroutine to a running asyncio loop? Ie. one that is already executing a set of coroutines.

I guess as a workaround one could wait for existing coroutines to complete and then initialize a new loop (with the additional coroutine). But is there a better way?


how to add a coroutine to a running asyncio loop?

I am trying to download a PDF file from a website and save it to disk. My attempts either fail with encoding errors or result in blank PDFs.

    In [1]: import requests
    
    In [2]: url = &#39;http://www.hrecos.org//images/Data/forweb/HRTVBSH.Metadata.pdf&#39;
    
    In [3]: response = requests.get(url)
    
    In [4]: with open(&#39;/tmp/metadata.pdf&#39;, &#39;wb&#39;) as f:
       ...:     f.write(response.text)
    ---------------------------------------------------------------------------
    UnicodeEncodeError                        Traceback (most recent call last)
    &lt;ipython-input-4-4be915a4f032&gt; in &lt;module&gt;()
          1 with open(&#39;/tmp/metadata.pdf&#39;, &#39;wb&#39;) as f:
    ----&gt; 2     f.write(response.text)
          3 
    
    UnicodeEncodeError: &#39;ascii&#39; codec can&#39;t encode characters in position 11-14: ordinal not in range(128)
    
    In [5]: import codecs
    
    In [6]: with codecs.open(&#39;/tmp/metadata.pdf&#39;, &#39;wb&#39;, encoding=&#39;utf8&#39;) as f:
       ...:     f.write(response.text)
       ...: 

I know it is a codec problem of some kind but I can&#39;t seem to get it to work.

Download and save PDF file with Python requests module

I&#39;m trying to install pip3, but I&#39;m not having any luck. Also, I tried `sudo install` and it did not work. How could I install pip3 on my Mac?

&lt;!-- language: none --&gt;

    sudo easy_install pip3
    Password:
    Searching for pip3
    Reading https://pypi.python.org/simple/pip3/
    Couldn&#39;t find index page for &#39;pip3&#39; (maybe misspelled?)
    Scanning index of all packages (this may take a while)
    Reading https://pypi.python.org/simple/
       
    No local packages or download links found for pip3
    error: Could not find suitable distribution for Requirement.parse(&#39;pip3&#39;)


How can I install Python&#39;s pip3 on my Mac?

I am trying to do a &quot;Hello World&quot; program in Cython, following this tutorial http://docs.cython.org/src/tutorial/cython_tutorial.html#cython-hello-world

I created `helloworld.pyx`

    print(&quot;Hello World&quot;)

and `setup.py`:

    from distutils.core import setup
    from Cython.Build import cythonize
    
    setup(
        ext_modules = cythonize(&quot;helloworld.pyx&quot;)
    )

How can I change setup.py to specify that my source is Python 3, rather than Python 2 like in the tutorial? If I invoke &quot;cython&quot; command from the command line, it accepts `-3` option. But if I compile with `python setup.py build_ext --inplace` like shown in the tutorial, how do I specify Python 3 source? It may not matter much for a Hello World program, but will matter as I start using Cython for real projects.

How to specify Python 3 source in Cython&#39;s setup.py?

For the following code:

    logger.debug(&#39;message: {}&#39;.format(&#39;test&#39;))

`pylint` produces the following warning:

&gt; **logging-format-interpolation (W1202):**
&gt; 
&gt; Use % formatting in logging functions and pass the % parameters as
&gt; arguments Used when a logging statement has a call form of
&gt; “logging.&lt;logging method&gt;(format_string.format(format_args...))”. Such
&gt; calls should use % formatting instead, but leave interpolation to the
&gt; logging function by passing the parameters as arguments.

I know I can turn off this warning, but I&#39;d like to understand it. I assumed using `format()` is the preferred way to print out statements in Python 3. Why is this not true for logger statements?

PyLint message: logging-format-interpolation

I generally use Python 2.7 but recently installed Python 3.5 using Miniconda on Mac OS X. Different libraries have been installed for these two versions of python. Now, the entering either of the keywords &#39;python&#39; or &#39;python3&#39; in terminal invokes python 3.5, and &#39;python2&#39; returns &#39;-bash: python2: command not found&#39;. How can I now invoke them specifically using aliases &#39;python2&#39; and &#39;python3&#39; respectively?

I am currently using OS X El Capitan.

Switch between python 2.7 and python 3.5 on Mac OS X

I am trying to download files from google drive and all I have is the drive&#39;s URL.

I have read about google API that talks about some `drive_service` and `MedioIO`, which also requires some credentials( mainly JSON `file/OAuth`). But I am unable to get any idea about how it is working. 

Also, tried `urllib2.urlretrieve`, but my case is to get files from the drive. Tried `wget` too but no use.

Tried `PyDrive` library. It has good upload functions to drive but no download options.

Any help will be appreciated.
Thanks.

Content Type	Original Author	Original Content on Stackoverflow
Question	Eamonn Gormley	View Question on Stackoverflow
Solution 1 - Python	Martijn Pieters	View Answer on Stackoverflow
Solution 2 - Python	Aryan Beezadhur	View Answer on Stackoverflow
Solution 3 - Python	Ilya V. Schurov	View Answer on Stackoverflow

Need to install urllib2 for Python 3.5.1

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

Solution 3 - Python

What is the difference between JavaScript promises and async await?

gitk will not start on Mac: unknown color name "lime"

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