`r` means the string will be treated as **raw string**.

See the official [Python 2 Reference][1] about &quot;String literals&quot;:

&gt; When an `&#39;r&#39;` or `&#39;R&#39;` prefix is present, a character following a
&gt; backslash is included in the string without change, and *all
&gt; backslashes are left in the string*. For example, the string literal
&gt; `r&quot;\n&quot;` consists of two characters: a backslash and a lowercase `&#39;n&#39;`.
&gt; String quotes can be escaped with a backslash, but the backslash
&gt; remains in the string; for example, `r&quot;\&quot;&quot;` is a valid string literal
&gt; consisting of two characters: a backslash and a double quote; `r&quot;\&quot;` is
&gt; not a valid string literal (even a raw string cannot end in an odd
&gt; number of backslashes). Specifically, *a raw string cannot end in a
&gt; single backslash* (since the backslash would escape the following quote
&gt; character). Note also that a single backslash followed by a newline is
&gt; interpreted as those two characters as part of the string, *not* as a
&gt; line continuation.


  [1]: https://docs.python.org/2/reference/lexical_analysis.html#string-literals

I have `DataFrame` with column `Sales`.

How can I split it into 2 based on `Sales` value?

First `DataFrame` will have data with `&#39;Sales&#39; &lt; s` and second with `&#39;Sales&#39; &gt;= s` 

Pandas split DataFrame by column value

I m using `PhpStorm 10` on `Ubuntu 14.04`.
I get the following error when at start :

    8:08:47 AM IBus prior to 1.5.11 may cause input problems. See IDEA-78860 for details.
               Do not show again.
    8:09:18 AM Platform and Plugin Updates: PhpStorm is ready to update.

How could I solve this, if any solution to upgrade `IBus` or change it with other library to do the same thing.

Resolving IBus Issue - IBus prior to 1.5.11 may cause input problems

I want to understand why do we use a r before a path name in python such as

    dirname = r&#39;C:\temp\parts&#39;



What does an &#39;r&#39; represent before a string in python?

<p>I want to understand why do we use a r before a path name in python such as</p>
<pre><code class="hljs language-python">dirname = <span class="hljs-string">r'C:\temp\parts'</span>
</code></pre>


Every time I run my app that uses Flask-SQLAlchemy I get the following warning that the `SQLALCHEMY_TRACK_MODIFICATIONS` option will be disabled.

    /home/david/.virtualenvs/flask-sqlalchemy/lib/python3.5/site-packages/flask_sqlalchemy/__init__.py:800: UserWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True to suppress this warning.
      warnings.warn(&#39;SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True to suppress this warning.&#39;)

I tried to find out what this option does, but the Flask-SQLAlchemy documentation isn&#39;t clear about what uses this tracking.

&gt; `SQLALCHEMY_TRACK_MODIFICATIONS`
&gt; 
&gt; If set to True (the default) Flask-SQLAlchemy will track modifications of objects and emit signals. This requires extra memory and can be disabled if not needed.

How do I find out if my project requires `SQLALCHEMY_TRACK_MODIFICATIONS = True` or if I can safely disable this feature and save memory on my server?

How do I know if I can disable SQLALCHEMY_TRACK_MODIFICATIONS?

I have [answered](https://stackoverflow.com/a/22679558/2588818) a question regarding absolute imports in Python, which I thought I understood based on reading [the Python 2.5 changelog](https://docs.python.org/2.5/whatsnew/pep-328.html) and accompanying [PEP](https://www.python.org/dev/peps/pep-0328/). However, upon installing Python 2.5 and attempting to craft an example of properly using `from __future__ import absolute_import`, I realize things are not so clear.

Straight from the changelog linked above, this statement accurately summarized my understanding of the absolute import change:

&gt; Let&#39;s say you have a package directory like this:

&gt;     pkg/
    pkg/__init__.py
    pkg/main.py
    pkg/string.py

&gt; This defines a package named `pkg` containing the `pkg.main` and `pkg.string` submodules.

&gt; Consider the code in the main.py module. What happens if it executes the statement `import string`? In Python 2.4 and earlier, it will first look in the package&#39;s directory to perform a relative import, finds pkg/string.py, imports the contents of that file as the `pkg.string` module, and that module is bound to the name `&quot;string&quot;` in the `pkg.main` module&#39;s namespace.

So I created this exact directory structure:

    $ ls -R
    .:
    pkg/
    
    ./pkg:
    __init__.py  main.py  string.py

`__init__.py` and `string.py` are empty. `main.py` contains the following code:

    import string
    print string.ascii_uppercase

As expected, running this with Python 2.5 fails with an `AttributeError`:

    $ python2.5 pkg/main.py
    Traceback (most recent call last):
      File &quot;pkg/main.py&quot;, line 2, in &lt;module&gt;
        print string.ascii_uppercase
    AttributeError: &#39;module&#39; object has no attribute &#39;ascii_uppercase&#39;

However, further along in the 2.5 changelog, we find this (emphasis added):

&gt; In Python 2.5, you can switch `import`&#39;s behaviour to absolute imports using a `from __future__ import absolute_import` directive. This absolute-import behaviour will become the default in a future version (probably Python 2.7). **Once absolute imports are the default, `import string` will always find the standard library&#39;s version.**

I thus created `pkg/main2.py`, identical to `main.py` but with the additional future import directive. It now looks like this:

    from __future__ import absolute_import
    import string
    print string.ascii_uppercase

Running this with Python 2.5, however... fails with an `AttributeError`:

    $ python2.5 pkg/main2.py
    Traceback (most recent call last):
      File &quot;pkg/main2.py&quot;, line 3, in &lt;module&gt;
        print string.ascii_uppercase
    AttributeError: &#39;module&#39; object has no attribute &#39;ascii_uppercase&#39;

This pretty flatly contradicts the statement that `import string` will **always** find the std-lib version with absolute imports enabled. What&#39;s more, despite the warning that absolute imports are scheduled to become the &quot;new default&quot; behavior, I hit this same problem using both Python 2.7, with or without the `__future__` directive:

    $ python2.7 pkg/main.py
    Traceback (most recent call last):
      File &quot;pkg/main.py&quot;, line 2, in &lt;module&gt;
        print string.ascii_uppercase
    AttributeError: &#39;module&#39; object has no attribute &#39;ascii_uppercase&#39;

    $ python2.7 pkg/main2.py
    Traceback (most recent call last):
      File &quot;pkg/main2.py&quot;, line 3, in &lt;module&gt;
        print string.ascii_uppercase
    AttributeError: &#39;module&#39; object has no attribute &#39;ascii_uppercase&#39;

as well as Python 3.5, with or without (assuming the `print` statement is changed in both files):

    $ python3.5 pkg/main.py
    Traceback (most recent call last):
      File &quot;pkg/main.py&quot;, line 2, in &lt;module&gt;
        print(string.ascii_uppercase)
    AttributeError: module &#39;string&#39; has no attribute &#39;ascii_uppercase&#39;

    $ python3.5 pkg/main2.py
    Traceback (most recent call last):
      File &quot;pkg/main2.py&quot;, line 3, in &lt;module&gt;
        print(string.ascii_uppercase)
    AttributeError: module &#39;string&#39; has no attribute &#39;ascii_uppercase&#39;

-------------

I have tested other variations of this. Instead of `string.py`, I have created an empty module -- a directory named `string` containing only an empty `__init__.py` -- and instead of issuing imports from `main.py`, I have `cd`&#39;d to `pkg` and run imports directly from the REPL. Neither of these variations (nor a combination of them) changed the results above. I cannot reconcile this with what I have read about the `__future__` directive and absolute imports.

It seems to me that this is easily explicable by [the following](https://docs.python.org/2/library/sys.html#sys.path) (this is from the Python 2 docs but this statement remains unchanged in the same docs for Python 3):

&gt; ### sys.path

&gt; (...)

&gt; As initialized upon program startup, the first item of this list, `path[0]`, is the directory containing the script that was used to invoke the Python interpreter. If the script directory is not available (e.g. if the interpreter is invoked interactively or if the script is read from standard input), `path[0]` is the empty string, **which directs Python to search modules in the current directory first.**

So what am I missing? Why does the `__future__` statement seemingly not do what it says, and what is the resolution of this contradiction between these two sections of documentation, as well as between described and actual behavior?

What does from __future__ import absolute_import actually do?

I am using Spark 1.3 and would like to join on multiple columns using python interface (SparkSQL)

The following works:

I first register them as temp tables.

    numeric.registerTempTable(&quot;numeric&quot;)
    Ref.registerTempTable(&quot;Ref&quot;)

    test  = numeric.join(Ref, numeric.ID == Ref.ID, joinType=&#39;inner&#39;)

I would now like to join them based on multiple columns.

I get `SyntaxError`: invalid syntax with this:

    test  = numeric.join(Ref,
       numeric.ID == Ref.ID AND numeric.TYPE == Ref.TYPE AND
       numeric.STATUS == Ref.STATUS ,  joinType=&#39;inner&#39;)


How to join on multiple columns in Pyspark?

           Y1961      Y1962      Y1963      Y1964      Y1965  Region
    0  82.567307  83.104757  83.183700  83.030338  82.831958  US
    1   2.699372   2.610110   2.587919   2.696451   2.846247  US
    2  14.131355  13.690028  13.599516  13.649176  13.649046  US
    3   0.048589   0.046982   0.046583   0.046225   0.051750  US
    4   0.553377   0.548123   0.582282   0.577811   0.620999  US

In the above dataframe, I would like to get average of each row. currently, I am doing this:

    df.mean(axis=0)

However, this does away with the Region column as well. how can I compute mean and also retain Region column

Compute row average in pandas

Function `foo` prints to console. I want to test the console print. How can I achieve this in python?

Need to test this function, has NO return statement : 

    def foo(inStr):
       print &quot;hi&quot;+inStr

My test : 
    
    def test_foo():
        cmdProcess = subprocess.Popen(foo(&quot;test&quot;), stdout=subprocess.PIPE)
        cmdOut = cmdProcess.communicate()[0]
        self.assertEquals(&quot;hitest&quot;, cmdOut)




Python: Write unittest for console print

Code:

    import numpy as np
    import cv
Console:

    &gt;&gt;&gt; runfile(&#39;/Users/isaiahnields/.spyder2/temp.py&#39;, wdir=&#39;/Users/isaiahnields/.spyder2&#39;)
    RuntimeError: module compiled against API version a but this version of numpy is 9
    Traceback (most recent call last):
     File &quot;&lt;stdin&gt;&quot;, line 1, in &lt;module&gt;
    File &quot;/Applications/Spyder-Py2.app/Contents/Resources/lib/python2.7/spyderlib/widgets/externalshell/sitecustomize.py&quot;, line 685, in runfile
    execfile(filename, namespace)
    File &quot;/Applications/Spyder-Py2.app/Contents/Resources/lib/python2.7/spyderlib/widgets/externalshell/sitecustomize.py&quot;, line 78, in execfile
    builtins.execfile(filename, *where)
    File &quot;/Users/isaiahnields/.spyder2/temp.py&quot;, line 9, in &lt;module&gt;
    import cv
    File &quot;/Applications/Spyder-Py2.app/Contents/Resources/lib/python2.7/cv.py&quot;, line 1, in &lt;module&gt;
    from cv2.cv import *
    ImportError: numpy.core.multiarray failed to import
    &gt;&gt;&gt; 

System Info: OS X El Capitan, Macbook Air, 1.3 GHz Intel Core i5, 8 GB 1600 HMz DDR3

I have already attempted updating numpy. I had to add cv.py to the python2.7 folder in Spyder-Py2 is there something else I need to add?

RuntimeError: module compiled against API version a but this version of numpy is 9

I have a dataframe with values like 

    A B
    1 4
    2 6
    3 9

I need to add a new column by adding values from column A and B, like

    A B C
    1 4 5
    2 6 8
    3 9 12

I believe this can be done using lambda function, but I can&#39;t figure out how to do it.


Make new column in Panda dataframe by adding values from other columns

I am trying to work on neural networks in Python using the following Keras packages:

    from keras.utils import np_utils
    from keras.layers.core import Dense, Activation, Dropout
    from keras.models import Sequential
    from keras.layers.core import Dense, Dropout, Activation, Flatten
    from keras.layers.convolutional import Convolution2D, MaxPooling2D
    from keras.optimizers import SGD

But, I am getting the following error:

     15 import theano
     ---&gt; 16 from theano import gof
     17 from theano.compat.python2x import partial
     18 import theano.compile.mode
     ImportError: cannot import name gof

Installing installed `conda install keras`. Later I tried to use `pip install Theano`, but it did not work. I Tried to install using `pip install git`, but I am getting this error: `cannot find command git.` So I installed Git and I set the environment variables.

So, is there any procedure to install these packages?


Content Type	Original Author	Original Content on Stackoverflow
Question	Rahul	View Question on Stackoverflow
Solution 1 - Python	Rahul Tripathi	View Answer on Stackoverflow

What does an 'r' represent before a string in python?

Python Problem Overview

Python Solutions

Solution 1 - Python

Resolving IBus Issue - IBus prior to 1.5.11 may cause input problems

Pandas split DataFrame by column value

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