Since [v0.15](https://github.com/elixir-lang/elixir/commit/380bf1e279e782d600a266cc6a3782ece0a2bf95) we have `Map.from_struct/1` which does exactly this.

    defmodule User do
      defstruct [:name]
    end

    Map.from_struct(%User{name: &quot;valim&quot;})
    #=&gt; %{name: &quot;valim&quot;}


There&#39;s another trick

    my_struct = %MyStruct{}
    my_map = Map.delete my_struct, :__struct__

    get_updates([{atom, any}]) ::
      {:ok, [Nadia.Model.Update.t]} |
      {:error, Nadia.Model.Error.t}

If successful it returns a list of Nadia.Model.Update.t. That&#39;s why you get that error.

FWIW, I wrote a library that will do this kind of thing for you automagically w/o having to pull the data structure apart. 

https://github.com/philosophers-stone/transform

This is from the test code: 

    test &quot;implement scrub of empty values from map&quot; do
      data = %{ :a =&gt; nil, :b =&gt; &quot;&quot;, :c =&gt; &quot;a&quot;}
      replace_empty = fn(string, _d) -&gt; if( string == &quot;&quot;, do: nil , else: string) end
      replace_nil = fn(map, _depth) -&gt;  for {k, v} &lt;- map, v != nil , into: %{}, do: {k, v} end
      potion = %{ BitString =&gt; replace_empty, Map =&gt; replace_nil}

      assert PhStTransform.transform(data, potion) == %{:c =&gt; &quot;a&quot;}

    end

Note, if data was a list of maps this would still work just fine. The PhStTransform library will just keep pulling the data apart until it finds a map. In your case you would use a replace_nil function that worked on the kinds of structs you are interested in. 


I have a Lambda function that has an exposed API Gateway endpoint, and I can get the URL for that via the AWS console. However, I would like to get that URL via API call. Neither the [Lambda API documentation][1] nor the [API Gateway documentation][2] seem to have that information (or perhaps I&#39;ve missed it), so is this even possible in the first place?


  [1]: http://docs.aws.amazon.com/lambda/latest/dg/API_Operations.html
  [2]: http://docs.aws.amazon.com/apigateway/api-reference/resource/api-gateway/

How do I find the API endpoint of a lambda function?

I am trying to make a POST request to the following page: http://search.cpsa.ca/PhysicianSearch

In order to simulate clicking the &#39;Search&#39; button without filling out any of the form, which adds data to the page. I got the POST header information by clicking on the button while looking at the network tab in Chrome Developer Tools. The reason I&#39;m posting this instead of just copying solutions from the other similar problems is that I believe I may have not gotten the correct header information. 

Is it properly formatted and did I grab the right information? I&#39;ve never made a POST request before.

This is what I&#39;ve managed to piece together:

    import urllib.parse
    import urllib.request
    
    
    data = urllib.parse.urlencode({&#39;Host&#39;: &#39;search.cpsa.ca&#39;, &#39;Connection&#39;: &#39;keep-alive&#39;, &#39;Content-Length&#39;: 23796,
                                         &#39;Origin&#39;: &#39;http://search.cpsa.ca&#39;, &#39;Content-Type&#39;: &#39;application/x-www-form-urlencoded; charset=UTF-8&#39;,
                                         &#39;Cahce-Control&#39;: &#39;no-cache&#39;, &#39;X-Requested-With&#39;: &#39;XMLHttpRequest&#39;,
                                         &#39;X-MicrosoftAjax&#39;: &#39;Delta=true&#39;, &#39;Accept&#39;: &#39;*/*&#39;,
                                         &#39;Referer&#39;: &#39;http://search.cpsa.ca/PhysicianSearch&#39;,
                                         &#39;Accept-Encoding&#39;: &#39;gzip, deflate&#39;,
                                         &#39;Accept-Language&#39;: &#39;en-GB,en-US;q=0.8,en;q=0.6&#39;,
                                         &#39;Cookie&#39;: &#39;ASP.NET_SessionId=kcwsgio3dchqjmyjtwue402c; _ga=GA1.2.412607756.1459536682; _gat=1&#39;})
    
    
    url = &quot;http://www.musi-cal.com/cgi-bin/query?%s&quot;
    
    data = data.encode(&#39;ascii&#39;)
    with urllib.request.urlopen(&quot;http://search.cpsa.ca/PhysicianSearch&quot;, data) as f:
        print(f.read().decode(&#39;utf-8&#39;))

This solution outputs the page&#39;s HTML, but not with any of the data I wanted to retrieve from the POST request.

Python - make a POST request using Python 3 urllib

I&#39;m trying to convert a struct to a map to be able to clean all the nil values

I&#39;m currently using this code 


	  case Nadia.get_updates  do
	    {:ok, results} -&gt;
		  Map.from_struct(results)
		  |&gt; Enum.filter(fn {_, v} -&gt; v != nil end)
		  |&gt; Enum.into(%{})

Note: Nadia.get_updates returns the following structure:
https://hexdocs.pm/nadia/Nadia.Model.Update.html#t:t/0

Yet I&#39;m always receiving the following error: no function clause matching in Map.from_struct/1


Elixir convert struct to map

I'm trying to convert a struct to a map to be able to clean all the nil values
I'm currently using this code
<pre><code class="hljs language-ruby"> case Nadia.get_updates do
 {:ok, results} ->
	 Map.from_struct(results)
	 |> Enum.filter(fn {_, v} -> v != nil end)
	 |> Enum.into(%{})
</code></pre>
Note: Nadia.get_updates returns the following structure:
<a href="https://hexdocs.pm/nadia/Nadia.Model.Update.html#t:t/0" target="_blank" rel="noopener noreferrer">https://hexdocs.pm/nadia/Nadia.Model.Update.html#t:t/0</a>
Yet I'm always receiving the following error: no function clause matching in Map.from_struct/1

I have a dictionary and am trying to write it to a file.

    exDict = {1:1, 2:2, 3:3}
    with open(&#39;file.txt&#39;, &#39;r&#39;) as file:
        file.write(exDict)

I then have the error

&lt;!-- language: lang-none --&gt;

    file.write(exDict)
    TypeError: must be str, not dict

So I fixed that error but another error came

    exDict = {111:111, 222:222}
    with open(&#39;file.txt&#39;, &#39;r&#39;) as file:
        file.write(str(exDict))

The error:

&lt;!-- language: lang-none --&gt;

    file.write(str(exDict))
    io.UnsupportedOperation: not writable

I have no idea what to do as I am still a beginner at python.
If anyone knows how to resolve the issue, please provide an answer.

NOTE: I am using python 3, not python 2


Writing a dictionary to a text file?

I am practicing using type hints in Python 3.5. One of my colleague uses `typing.Dict`:

    import typing
    
    
    def change_bandwidths(new_bandwidths: typing.Dict,
                          user_id: int,
                          user_name: str) -&gt; bool:
        print(new_bandwidths, user_id, user_name)
        return False
    
    
    def my_change_bandwidths(new_bandwidths: dict,
                             user_id: int,
                             user_name: str) -&gt;bool:
        print(new_bandwidths, user_id, user_name)
        return True
    
    
    def main():
        my_id, my_name = 23, &quot;Tiras&quot;
        simple_dict = {&quot;Hello&quot;: &quot;Moon&quot;}
        change_bandwidths(simple_dict, my_id, my_name)
        new_dict = {&quot;new&quot;: &quot;energy source&quot;}
        my_change_bandwidths(new_dict, my_id, my_name)
    
    if __name__ == &quot;__main__&quot;:
        main()

Both of them work just fine, there doesn&#39;t appear to be a difference. 

I have read the [`typing` module documentation](https://docs.python.org/3/library/typing.html).

Between `typing.Dict` or `dict` which one should I use in the program?


Difference between defining typing.Dict and dict?

When constructing a dictionary as follows:

    dict = { True: &#39;yes&#39;, 1: &#39;No&#39;}

When I run it in the interactive Python interpreter the dict is represented this way:

    dict = {True: &#39;No&#39;}

I understand that the values `True` and `1` are equal due to the type coercion because when comparing numeric types, the narrowed type is widened to the other type (boolean is a child of integer). So as I understood from the documentation, when we enter `True == 1` Python converts `True` to `1` and compares them.

What I don&#39;t understand is why the `True` is selected as a key instead of `1`.

I am missing something?


Choice made by Python 3.5 to choose the keys when comparing them in a dictionary

I see how you can access your collection by key. However, the hash function itself has a lot of operations behind the scenes, doesn&#39;t it?

Assuming you have a nice hash function which is very efficient, it still may take many operations.

Can this be explained?

Why is accessing an element of a dictionary by key O(1) even though the hash function may not be O(1)?

How to sort this map by value?

    var map = new Map();
    map.set(&#39;orange&#39;, 10);
    map.set(&#39;apple&#39;, 5);
    map.set(&#39;banana&#39;, 20);
    map.set(&#39;cherry&#39;, 13);



How to sort a map by value in JavaScript?

I know that in C we cannot return an array from a function, but a pointer to an array. But I want to know what is the special thing about `structs` that makes them return-able by functions even though they may contain arrays.

Why is the `struct` wrapping makes the following program valid?

	#include &lt;stdio.h&gt;

	struct data {
		char buf[256];
	};

	struct data Foo(const char *buf);

	int main(void)
	{
		struct data obj;
		obj = Foo(&quot;This is a sentence.&quot;);
		printf(&quot;%s\n&quot;, obj.buf);
		return 0;
	}

	struct data Foo(const char *buf)
	{
		struct data X;
		strcpy(X.buf, buf);
		return X;
	}

What is special about structs?

There are multiple answers/techniques to the below question:

1. How to set default values to golang structs?
2. How to initialize structs in golang

I have a couple of answers but further discussion is required.

How to set default values in Go structs

I&#39;m a beginner C programmer, yesterday I learned the use of C structs and the possible application of these ones about the resolution of specific problems. However when I was experimenting with my C IDE (Codeblocks 16.01) in order to learn this aspect of C programming, I&#39;ve encountered a strange issue. The code is the following:
 
    #include &lt;stdio.h&gt;

    #define N 30

    typedef struct{
         char name[N];
         char surname[N];
         int age;
    } data;

    int main() {
         data s1;
         s1.name=&quot;Paolo&quot;;
         s1.surname = &quot;Rossi&quot;;
         s1.age = 19;
         getchar();
         return 0;
    }

During the compilation, the compiler (GCC 4.9.3-1 under Windows) reported me an error that says 

&gt; &quot;error: assignment to expression with array type error&quot; 

on instruction 

    s1.name=&quot;Paolo&quot; 
    s1.surname=&quot;Rossi&quot; 

while if I do

    data s1 = {&quot;Paolo&quot;, &quot;Rossi&quot;, 19};
it works. 
What am I doing wrong? 

&quot;error: assignment to expression with array type error&quot; when I assign a struct field (C)

To start off, I want to say that I&#39;m aware there are **many** articles and questions within SO that refer to the `indirect` keyword in Swift. 

The most popular explanation for the usage of `indirect` is to allow for recursive enums. 

Rather than just knowing about what `indirect` allows us to do, I would like to know **how** it allows us to use recursive enums.

## Questions:
 
Is it because enums are value types and value types do not scale well if they are built in a recursive structure? Why?

Does `indirect` modify the value type behaviour to behave more like a reference type? 

The following two examples compile just fine. What is the difference?

    indirect enum BinaryTree&lt;T&gt; {
      case node(BinaryTree&lt;T&gt;, T, BinaryTree&lt;T&gt;)
      case empty
    }
    
    enum BinaryTree&lt;T&gt; {
      indirect case node(BinaryTree&lt;T&gt;, T, BinaryTree&lt;T&gt;)
      case empty
    }

indirect enums and structs

I&#39;m not sure which of both are better to define constants. A struct or a enum. A struct will be copied every time i use it or not? When i think about a struct with `static let` constants it makes no sense that it will  copied all the time, in my opinion. But if it won&#39;t copied then it doesn&#39;t matter what I take?

What advantages does the choice of a struct or enum?

[Francisco say use Struct&#39;s.][1]

[Ray Wenderlich say use Enum&#39;s. But I lack the justification.][2]


  [1]: https://stackoverflow.com/questions/26252233/global-constants-file-in-swift
  [2]: https://github.com/raywenderlich/swift-style-guide#constants

Swift constants: Struct or Enum

How to sleep / wait for one second?

Best I could find was something like this (in iex):

    IO.puts &quot;foo&quot; ; :timer.sleep(1); IO.puts &quot;bar&quot;

But both of my puts happen with no delay.

Elixir Sleep / Wait for 1 Second

This question is in the context of the Beam VM and the capabilities that it provides, not in the general context of what a Turing complete language can do. I want to invest some time to learn either pure Erlang or Elixir. I get the basic differences between the two and I am leaning towards Elixir because of the macros, better syntax and faster development of the language this day.

My question is: if I choose Elixir, will I stumble on something that I cannot do in it, but can do in Erlang? Can I use all the OTP stuff, all the Erlang libraries, code reload, etc. with Elixir?

I am not asking for someone&#39;s preference between the two; just facts about the possibilities of the languages. Preferably from someone who used both in production.


Are there things Elixir can do that Erlang cannot, or vice versa?

How to do the similar conditional one-line check in Elixir?

```lang-elixir
if (x &gt; 0) ? x : nil
```

Is this the only equivalent in elixir world?

```lang-elixir
if true, do: 1, else: 2
```

Simulate ternary operator in Elixir

I need to generate a random number. I found the [`Enum.random/1`](https://hexdocs.pm/elixir/Enum.html#random/1) function, but it expects an enumerable such as a list or range of numbers.

Is that the only way to get a random number?

How to generate a random number in Elixir?

I&#39;m trying to format a Postgres date representation into a ISO 8601 string. I&#39;m assuming that there is a Postgres function that can do it, but I found the documentation short on examples. 

My query is 

    SELECT
      now()::timestamp

which returns

    [{{2016, 8, 9}, {3, 56, 55, 754181}}]

I&#39;m trying to get the date into a format that looks more like 
`2016-8-9T03:56:55+00:00`. 

What changes do I need to make to my query to make that happen? Thanks for your help.

Turn postgres date representation into ISO 8601 string

I&#39;ve created a bot in telegram

I want to send bold and italic text with HTML page to bot

My HTML code is:

    &lt;html&gt;
    &lt;head&gt;&lt;title&gt;Telegram&lt;/title&gt;&lt;/head&gt;
    &lt;body&gt;
    	&lt;form method=&quot;GET&quot; action=&quot;https://api.telegram.org/bot(token)/sendMessage&quot;&gt;
    		&lt;input type=&quot;hidden&quot; name=&quot;chat_id&quot; value=&quot;@testadminch&quot;&gt;
    		&lt;input type=&quot;hidden&quot; name=&quot;parse_mod&quot; value=&quot;markdown&quot;&gt;
    		&lt;textarea name=&quot;text&quot;&gt;&lt;/textarea&gt;
    		&lt;input type=&quot;submit&quot; value=&quot;Submit&quot;&gt;
    	&lt;/form&gt;
    &lt;/body&gt;
    &lt;/html&gt;

If I send `*bold*` the output should be **bold** but it doesn&#39;t work


send bold &amp; italic text on telegram bot with html

My telegram bot receives messages sent by user to my bot in private chats but not receives messages sent by users in group chats. Any options/api for getting group chat messages also,.

Content Type	Original Author	Original Content on Stackoverflow
Question	user2070502	View Question on Stackoverflow
Solution 1 - Dictionary	Juliano	View Answer on Stackoverflow
Solution 2 - Dictionary	radzserg	View Answer on Stackoverflow
Solution 3 - Dictionary	Sasha Fonseca	View Answer on Stackoverflow
Solution 4 - Dictionary	Fred the Magic Wonder Dog	View Answer on Stackoverflow

Elixir convert struct to map

Dictionary Problem Overview

Dictionary Solutions

Solution 1 - Dictionary

Solution 2 - Dictionary

Solution 3 - Dictionary

Solution 4 - Dictionary

Python - make a POST request using Python 3 urllib

How do I find the API endpoint of a lambda function?

Attributions