Python 3 interprets string literals as Unicode strings, and therefore your `\d` is treated as an escaped Unicode character.

Declare your RegEx pattern as a raw string instead by prepending `r`, as below:

    r&#39;\nRevision: (\d+)\n&#39;

This also means you can drop the escapes for `\n` as well since these will just be parsed as newline characters by `re`.

I have a simple dotnet core class library with a single XUnit test method:

    TestLib.csproj:
    &lt;Project Sdk=&quot;Microsoft.NET.Sdk&quot;&gt;
    
      &lt;PropertyGroup&gt;
        &lt;TargetFramework&gt;netstandard2.0&lt;/TargetFramework&gt;
      &lt;/PropertyGroup&gt;
    
      &lt;ItemGroup&gt;
        &lt;PackageReference Include=&quot;Microsoft.NET.Test.SDK&quot; Version=&quot;15.9.0&quot; /&gt;
        &lt;PackageReference Include=&quot;xunit&quot; Version=&quot;2.4.1&quot; /&gt;
        &lt;PackageReference Include=&quot;xunit.runner.console&quot; Version=&quot;2.4.1&quot;&gt;
          &lt;IncludeAssets&gt;runtime; build; native; contentfiles; analyzers&lt;/IncludeAssets&gt;
          &lt;PrivateAssets&gt;all&lt;/PrivateAssets&gt;
        &lt;/PackageReference&gt;
        &lt;PackageReference Include=&quot;xunit.runner.visualstudio&quot; Version=&quot;2.4.1&quot;&gt;
          &lt;IncludeAssets&gt;runtime; build; native; contentfiles; analyzers&lt;/IncludeAssets&gt;
          &lt;PrivateAssets&gt;all&lt;/PrivateAssets&gt;
        &lt;/PackageReference&gt;
        &lt;PackageReference Include=&quot;xunit.runners&quot; Version=&quot;2.0.0&quot; /&gt;
      &lt;/ItemGroup&gt;
    
    &lt;/Project&gt;

    BasicTest.cs:
    using Xunit;
    
    namespace TestLib
    {
        public class BasicTest
        {
            [Fact(DisplayName = &quot;Basic unit test&quot;)]
            [Trait(&quot;Category&quot;, &quot;unit&quot;)]
            public void TestStringHelper()
            {
                var sut = &quot;sut&quot;;
                var verify = &quot;sut&quot;;
    
                Assert.Equal(sut, verify);
            }
        }
    }

If I enter the project on the CLI and type `dotnet build` the project builds. If I type `dotnet test` I get this:

    C:\git\Testing\TestLib&gt; dotnet test
    C:\git\Testing\TestLib\TestLib.csproj : warning NU1701: Package &#39;xunit.runner.visualstudio 2.4.1&#39; was restored using &#39;.NETFramework,Version=v4.6.1&#39; instead of the project target framework &#39;.NETStandard,Version=v2.0&#39;. This package may not be fully compatible with your project.
    Build started, please wait...
    C:\git\Testing\TestLib\TestLib.csproj : warning NU1701: Package &#39;xunit.runner.visualstudio 2.4.1&#39; was restored using &#39;.NETFramework,Version=v4.6.1&#39; instead of the project target framework &#39;.NETStandard,Version=v2.0&#39;. This package may not be fully compatible with your project.
    Build completed.
    
    Test run for C:\git\Testing\TestLib\bin\Debug\netstandard2.0\TestLib.dll(.NETStandard,Version=v2.0)
    Microsoft (R) Test Execution Command Line Tool Version 16.0.0-preview-20181205-02
    Copyright (c) Microsoft Corporation.  All rights reserved.
    
    Starting test execution, please wait...
    Unable to find C:\git\Testing\TestLib\bin\Debug\netstandard2.0\testhost.dll. Please publish your test project and retry.
    
    Test Run Aborted.

What do I need to change to get the test to run?

If it helps, VS Code is not displaying the tests in its test explorer, either.

Unable to find testhost.dll. Please publish your test project and retry

In Kotlin is there an equivalent to the Swift code below?


    if let a = b.val {
    
    } else {
    
    }




Swift &#39;if let&#39; statement equivalent in Kotlin

I&#39;ve met a problem with `re` module in Python 3.6.5.
I have this pattern in my regular expression:

    &#39;\\nRevision: (\d+)\\n&#39;

But when I run it, I&#39;m getting a `DeprecationWarning`.

I searched for [the problem on SO][1], and haven&#39;t found the answer, actually - what should I use instead of `\d+`? Just `[0-9]+` or maybe something else?


  [1]: https://stackoverflow.com/search?q=DeprecationWarning%3A%20invalid%20escape%20sequence%20%5Cd

DeprecationWarning: invalid escape sequence - what to use instead of \d?

I've met a problem with <code>re</code> module in Python 3.6.5.
I have this pattern in my regular expression:
<pre><code class="hljs language-arduino">'\\nRevision: (\d+)\\n'
</code></pre>
But when I run it, I'm getting a <code>DeprecationWarning</code>.
I searched for <a href="https://stackoverflow.com/search?q=DeprecationWarning%3A%20invalid%20escape%20sequence%20%5Cd" target="_blank" rel="noopener noreferrer">the problem on SO</a>, and haven't found the answer, actually - what should I use instead of <code>\d+</code>? Just <code>[0-9]+</code> or maybe something else?

    import pandas as pd
    import numpy as np
    import cv2
    from torch.utils.data.dataset import Dataset
    
    class CustomDatasetFromCSV(Dataset):
        def __init__(self, csv_path, transform=None):
            self.data = pd.read_csv(csv_path)
            self.labels = pd.get_dummies(self.data[&#39;emotion&#39;]).as_matrix()
            self.height = 48
            self.width = 48
            self.transform = transform
    
        def __getitem__(self, index):
            pixels = self.data[&#39;pixels&#39;].tolist()
            faces = []
            for pixel_sequence in pixels:
                face = [int(pixel) for pixel in pixel_sequence.split(&#39; &#39;)]
                # print(np.asarray(face).shape)
                face = np.asarray(face).reshape(self.width, self.height)
                face = cv2.resize(face.astype(&#39;uint8&#39;), (self.width, self.height))
                faces.append(face.astype(&#39;float32&#39;))
            faces = np.asarray(faces)
            faces = np.expand_dims(faces, -1)
            return faces, self.labels
    
        def __len__(self):
            return len(self.data)



This is what I could manage to do by using references from other repositories. 
However, I want to split this dataset into train and test. 

How can I do that inside this class? Or do I need to make a separate class to do that?

How do I split a custom dataset into training and test datasets?

Is there an equivalent of list slicing `[1:]` from Python in C++ with vectors? I simply want to get all but the first element from a vector.

Python&#39;s list slicing operator:

    list1 = [1, 2, 3]
    list2 = list1[1:]  

    print(list2) # [2, 3]

C++ Desired result:

    std::vector&lt;int&gt; v1 = {1, 2, 3};
    std::vector&lt;int&gt; v2;
    v2 = v1[1:];

    std::cout &lt;&lt; v2 &lt;&lt; std::endl;  //{2, 3}

Slicing a vector in C++

I am trying to connect to a MySQL server with python connector. I created a new user `lcherukuri` with the authentication plugin `mysql_native_password`.

But I got the error

&gt; mysql.connector.errors.NotSupportedError: Authentication plugin &#39;caching_sha2_password&#39; is not supported

Can someone help me? 


    import mysql.connector

    cnx = mysql.connector.connect(user=&#39;lcherukuri&#39;, password=&#39;password&#39;,
                                  host=&#39;127.0.0.1&#39;,
                                  database=&#39;test&#39;)
    cnx.close()


[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/bmCIc.png

Authentication plugin &#39;caching_sha2_password&#39; is not supported

I want to get a percentage of a particular value in a df column. Say I have a df with (col1, col2 , col3, gender)  gender column has values of M, F, or Other. I want to get the percentage of M, F, Other values in the df. 

I have tried this, which gives me the number M, F, Other instances, but I want these as a percentage of the total number of values in the df.

    df.groupby(&#39;gender&#39;).size()

Can someone help?

Pandas get frequency of item occurrences in a column as percentage

This is a self-answered post. A common problem is to randomly generate dates between a given start and end date. 

There are two cases to consider:

1. random dates with a time component, and 
2. random dates without time

For example, given some start date `2015-01-01` and an end date `2018-01-01`, how can I sample N random dates between this range using pandas?


Generating random dates within a given range in pandas

Is it possible to define an interface which has some information on the format of a string? Take the following example:

    interface timeMarkers{
    	markerTime: string[]		
    };

an example would be:

    {
       markerTime: [&quot;0:00&quot;,&quot;1:30&quot;, &quot;1:48&quot;]                   
    }

My question: Is there a way to define the type for `markerTime` such that that the string value must always match this regex, instead of declaring it as simply `string[]` and going from there? 

`var reg = /[0-9]?[0-9]:[0-9][0-9]/;`


How to define a regex-matched string type in Typescript?

In my Javascript code, this regex `/(?&lt;=\/)([^#]+)(?=#*)/` works fine in Chrome, but in safari, I get: 

&gt; Invalid regular expression: invalid group specifier name

Any ideas?

Works in Chrome, but breaks in Safari: Invalid regular expression: invalid group specifier name /(?&lt;=\/)([^#]+)(?=#*)/

This probably isn&#39;t a VS Code-specific question but it&#39;s my tool of choice. 

I have a log file with a lot of lines containing the following:

`Company.Environment.Security.RightsBased.Policies.RightsUserAuthorizationPolicy`

Those are debug-level log records that clutter the file I&#39;m trying to process.  I&#39;m looking to remove the lines with that content. 

I&#39;ve looked into Regex but, unlike removing a blank line where you have the whole content in the search criteria (making find/replace easy), here I need to match from line break to line break on some criteria between the two, I think...

What are your thoughts on how criteria like that would work?

Visual Studio Code - Removing Lines Containing criteria

Why does this code output `02` in [tag:java-8] but `o2` in [tag:java-9] or above?

    &quot;o2&quot;.replaceAll(&quot;([oO])([^[0-9-]])&quot;, &quot;0$2&quot;)

Why does String.replaceAll() work differently in Java 8 from Java 9?

I stumbled across a surprising (to me) fact.

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-js --&gt;

    console.log(&quot;asdf&quot;.replace(/.*/g, &quot;x&quot;));

&lt;!-- end snippet --&gt;

Why *two* replacements?  It seems any non-empty string without newlines will produce exactly two replacements for this pattern.  Using a replacement function, I can see that the first replacement is for the entire string, and the second is for an empty string.  

Why is &quot;asdf&quot;.replace(/.*/g, &quot;x&quot;) == &quot;xx&quot;?

I am trying to use pytesseract in Python but I always end up with the following error:

```
    raise TesseractNotFoundError()
pytesseract.pytesseract.TesseractNotFoundError: tesseract is not installed or it&#39;s not in your path
```

However, pytesseract and Tesseract are installed on my system.

Example code that produces this error:
```python
import cv2
import pytesseract

img = cv2.imread(&#39;1d.png&#39;)
print(pytesseract.image_to_string(img))
```

How do I resolve this TesseractNotFoundError?

How do I resolve a TesseractNotFoundError?

How can I use [pathlib][1] to recursively iterate over all subdirectories of a given directory?

    p = Path(&#39;docs&#39;)
    for child in p.iterdir(): child

only seems to iterate over the immediate children of a given directory.

I know this is possible with `os.walk()` or `glob`, but I want to use pathlib because I like working with the path objects.


  [1]: https://docs.python.org/3/library/pathlib.html

Recursively iterate through all subdirectories using pathlib

Let&#39;s say I have defined a dataset in this way:

    filename_dataset = tf.data.Dataset.list_files(&quot;{}/*.png&quot;.format(dataset))

how can I get the number of elements that are inside the dataset (hence, the number of single elements that compose an epoch)?

I know that `tf.data.Dataset` already knows the dimension of the dataset, because the `repeat()` method allows repeating the input pipeline for a specified number of epochs. So it must be a way to get this information.

tf.data.Dataset: how to get the dataset size (number of elements in an epoch)?

I&#39;ve read many examples, blog posts, questions/answers about `asyncio` / `async` / `await` in Python 3.5+, many were complex, the simplest I found was probably [this one](https://stackoverflow.com/a/37345564/1422096).  
Still it uses `ensure_future`, and for learning purposes about asynchronous programming in Python, I would like to see an even more minimal example, and what are the *minimal tools necessary* to do a basic async / await example.

Question: is it possible to give a **simple example showing how `async` / `await` works**, by using only these two keywords + code to run the async loop + other Python code but no other `asyncio` functions?

Example: something like this:

    import asyncio
    
    async def async_foo():
        print(&quot;async_foo started&quot;)
        await asyncio.sleep(5)
        print(&quot;async_foo done&quot;)
    
    async def main():
        asyncio.ensure_future(async_foo())  # fire and forget async_foo()
        print(&#39;Do some actions 1&#39;)
        await asyncio.sleep(5)
        print(&#39;Do some actions 2&#39;)
    
    loop = asyncio.get_event_loop()
    loop.run_until_complete(main())

but without `ensure_future`, and still demonstrates how await / async works.

Simplest async/await example possible in Python

The [`typing` module documentation][1] says that the two code snippets below are equivalent.

&lt;!-- language: python --&gt;

    from typing import NamedTuple
    
    class Employee(NamedTuple):
        name: str
        id: int
        
and

&lt;!-- language: python --&gt;

    from collections import namedtuple
    
    Employee = namedtuple(&#39;Employee&#39;, [&#39;name&#39;, &#39;id&#39;])
    
Are they the exact same thing or, if not, what are the differences between the two implementations?


  [1]: https://docs.python.org/3/library/typing.html#typing.NamedTuple

Content Type	Original Author	Original Content on Stackoverflow
Question	mchfrnc	View Question on Stackoverflow
Solution 1 - Python	ACascarino	View Answer on Stackoverflow

DeprecationWarning: invalid escape sequence - what to use instead of \d?

Python Problem Overview

Python Solutions

Solution 1 - Python

Swift 'if let' statement equivalent in Kotlin

Unable to find testhost.dll. Please publish your test project and retry

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