The [`ConfigParser`][1] module raises an exception if one parses a simple Java-style **`.properties`**  file, whose content is key-value pairs (i..e without INI-style section headers). Is there some workaround?


  [1]: http://docs.python.org/2/library/configparser

parsing .properties file in Python

How can I obtain a list of key-value tuples from a [dict][1] in Python?

  [1]: http://docs.python.org/2/library/stdtypes.html#dict


Tuple list from dict in Python

I am finding some difficulty in accessing mutable dictionary keys and values in Objective-C.

Suppose I have this:

    NSMutableDictionary *xyz=[[NSMutableDictionary alloc] init];

I can set keys and values. Now, I just want to access each key and value, but I don&#39;t know the number of keys set.

In PHP it is very easy, something as follows:

    foreach ($xyz as $key =&gt; $value)

How is it possible in Objective-C?
 

for each loop in Objective-C for accessing NSMutable dictionary

I am trying to implement a dictionary (as in the physical book). I have a list of words and their meanings. 

What data structure / type does Java provide to store a list of words and their meanings as key/value pairs. 

How, given a key, can I find and return the value?


How do you create a dictionary in Java?

I&#39;m looking for a KeyValuePair class in Java.&lt;br&gt;
Since java.util heavily uses interfaces there is no concrete implementation provided, only the Map.Entry interface.

Is there some canonical implementation I can import?
It is one of those &quot;plumbers programming&quot; classes I hate to implement 100x times.

A KeyValuePair in Java

I know a map is a data structure that maps keys to values. Isn&#39;t a dictionary the same? What is the difference between a map and a dictionary&lt;sup&gt;1&lt;/sup&gt;?

---

&lt;sub&gt;
1. I am not asking for how they are defined in language X or Y (which seems to be what generally people are asking here on SO), I want to know what is their difference in theory.
&lt;/sub&gt;

What is the difference between a map and a dictionary?

I am new to python and I have a list of years and values for each year. What I want to do is check if the year already exists in a dictionary and if it does, append the value to that list of values for the specific key.

So for instance, I have a list of years and have one value for each year:

    2010  
    2  
    2009  
    4  
    1989  
    8  
    2009  
    7  

What I want to do is populate a dictionary with the years as keys and those single digit numbers as values. However, if I have 2009 listed twice, I want to append that second value to my list of values in that dictionary, so I want:  

    2010: 2  
    2009: 4, 7  
    1989: 8  

Right now I have the following:  

    d = dict()  
    years = []  
    
    (get 2 column list of years and values)
    
    for line in list:    
        year = line[0]   
        value = line[1]  
    
    for line in list:  
        if year in d.keys():  
            d[value].append(value)  
        else:  
            d[value] = value  
            d[year] = year  

append multiple values for one key in a dictionary

    var user = {};

now I want to create a `setUsers()` method that takes a key/value pair object and initializes the `user` variable.


    setUsers = function(data) {     
       // loop and init user    
    }


where data is like:

    234: &quot;john&quot;, 23421: &quot;smith&quot;, ....


How to loop through key/value object in Javascript?

I have an extremely large JSON object structured like this:  

    {A : 1, B : 2, C : 3, D : 4}
I need a function that can swap the values with keys in my object and I don&#39;t know how to do it. I would need an output like this:

    {1 : A, 2 : B, 3 : C, 4 : D}
Is there any way that I can do this would manually created a new object where everything is swapped?    
Thanks

Swap key with value in object

It is safe to say that the [EAV/CR][1] database model is bad.  That said, 

Question: **What database model, technique, or pattern should be used to deal with &quot;classes&quot; of attributes describing e-commerce products which can be changed at run time?**  

In a good E-commerce database, you will store classes of options (like TV resolution then have a resolution for each TV, but the next product may not be a TV and not have &quot;TV resolution&quot;).  How do you store them, search efficiently, and allow your users to setup product types with variable fields describing their products?  If the search engine finds that customers typically search for TVs based on console depth, you could add console depth to your fields, then add a single depth for each tv product type at run time.

There is a nice common feature among good e-commerce apps where they show a set of products, then have &quot;drill down&quot; side menus where you can see &quot;TV Resolution&quot; as a header, and the top five most common TV Resolutions for the found set.  You click one and it only shows TVs of that resolution, allowing you to further drill down by selecting other categories on the side menu.  These options would be the dynamic product attributes added at run time.

**Further discussion:**

So long story short, **are there any links out on the Internet or model descriptions that could &quot;academically&quot; fix the following setup?**  I thank Noel Kennedy for suggesting a category table, but the need may be greater than that.  I describe it a different way below, trying to highlight the significance.  I may need a viewpoint correction to solve the problem, or I may need to go deeper in to the EAV/CR.

Love the positive response to the EAV/CR model.  My fellow developers all say what Jeffrey Kemp touched on below: &quot;new entities must be modeled and designed by a professional&quot; (taken out of context, read his response below).  The problem is:

 - entities add and remove attributes weekly &lt;br /&gt; *(search keywords dictate future attributes)*
 - new entities arrive weekly &lt;br /&gt; *(products are assembled from parts)*
 - old entities go away weekly &lt;br /&gt; *(archived, less popular, seasonal)*

The customer wants to add attributes to the products for two reasons:

 - department / keyword search / comparison chart between like products
 - consumer product configuration before checkout

The attributes must have significance, not just a keyword search.  If they want to compare all cakes that have a &quot;whipped cream frosting&quot;, they can click cakes, click birthday theme, click whipped cream frosting, then check all cakes that are interesting knowing they all have whipped cream frosting.  This is not specific to cakes, just an example.

  [1]: http://en.wikipedia.org/wiki/Entity-attribute-value_model

Entity Attribute Value Database vs. strict Relational Model Ecommerce

All of the [examples](https://www.google.com/#q=kafka+producer+key+value) of [Kafka](https://kafka.apache.org/090/javadoc/index.html?org/apache/kafka/clients/producer/KafkaProducer.html) | [producers](https://www.tutorialspoint.com/apache_kafka/apache_kafka_simple_producer_example.htm) show the `ProducerRecord`&#39;s key/value pair as not only being the same type (all examples show `&lt;String,String&gt;`), but the same **value**. For example:

    producer.send(new ProducerRecord&lt;String, String&gt;(&quot;someTopic&quot;, Integer.toString(i), Integer.toString(i)));

But in the Kafka docs, I can&#39;t seem to find where the key/value concept (and its underlying purpose/utility) is explained. In traditional messaging (ActiveMQ, RabbitMQ, etc.) I&#39;ve always fired a message at a particular topic/queue/exchange. But Kafka is the first broker that seems to require key/value pairs instead of just a regulare &#39;ole string message.

So I ask: **What is the purpose/usefulness of requiring producers to send KV pairs?**

What&#39;s the purpose of Kafka&#39;s key/value pair-based messaging?

I&#39;m looking for a class in java that has key-value association, but without using hashes.  Here is what I&#39;m currently doing:

1. Add values to a `Hashtable`.
2. Get an iterator for the `Hashtable.entrySet()`.
3. Iterate through all values and:
   1. Get a `Map.Entry` for the iterator.
   2. Create an object of type `Module` (a custom class) based on the value.
   3. Add the class to a JPanel.
4. Show the panel.

The problem with this is that I do not have control over the order that I get the values back, so I cannot display the values in the a given order (without hard-coding the order).

I would use an `ArrayList` or `Vector` for this, but later in the code I need to grab the `Module` object for a given Key, which I can&#39;t do with an `ArrayList` or `Vector`.

Does anyone know of a free/open-source Java class that will do this, or a way to get values out of a `Hashtable` based on when they were added?

Thanks!

Java Class that implements Map and keeps insertion order?

I am looking for a better ***pattern*** for working with a list of elements which each need processed and then depending on the outcome are removed from the list. 

You can&#39;t use `.Remove(element)` inside a `foreach (var element in X)` (because it results in `Collection was modified; enumeration operation may not execute.` exception)... you also can&#39;t use `for (int i = 0; i &lt; elements.Count(); i++)` and `.RemoveAt(i)` because it disrupts your current position in the collection relative to `i`.

Is there an elegant way to do this?

How to remove elements from a generic list while iterating over it?

I am reading **RSS feed** and pushing both Title and Link into an Array in **Jquery**.
 
What i did is 

    var arr = [];
                
                $.getJSON(&quot;displayjson.php&quot;,function(data){
                    $.each(data.news, function(i,news){
                        var title = news.title;
                        var link = news.link;
                        arr.push({title : link});
                    });                      
                });

And i am reading that array again using 

    $(&#39;#show&#39;).click(function(){
                    $.each(arr, function(index, value){
                        alert( index +&#39; : &#39;+value);
                    });
                });

But it Giving me **Output** as 

    1:[Object Object]
    2:[Object Object]
    3:[Object Object]
like this ...

How i can get both **tile** and **link** as a pair ( **title as key and link as value**)

How to push both key and value into an Array in Jquery

I have a Swift dictionary. I want to get my key&#39;s value. Object for key method is not working for me. How do you get the value for a dictionary&#39;s key?

This is my dictionary:

    var companies = [&quot;AAPL&quot; : &quot;Apple Inc&quot;, &quot;GOOG&quot; : &quot;Google Inc&quot;, &quot;AMZN&quot; : &quot;Amazon.com, Inc&quot;, &quot;FB&quot; : &quot;Facebook Inc&quot;]
 
    for name in companies.keys { 
        print(companies.objectForKey(&quot;AAPL&quot;))
    }

How can I get key&#39;s value from dictionary in Swift?

I found that they have one key and multiple values which is unique.

What&#39;s the difference between std::multimap&lt;key, value&gt; and std::map&lt;key, std::set&lt;value&gt; &gt;

I got a problem when I try to modify the value of an item because its only a read only field.

    KeyValuePair&lt;Tkey, Tvalue&gt;

I&#39;ve tried different alternatives like:

    Dictionary&lt;Tkey, Tvalue&gt;

but there I have the same problem. Is there a way to set the value field to an new value?

How to modify a KeyValuePair value?

I have an object of the type `IEnumerable&lt;KeyValuePair&lt;T,U&gt;&gt; keyValueList`, I am using 

     var getResult= keyValueList.SingleOrDefault();
     if(getResult==/*default */)
     {
     }
     else
     {
     } 

How can I check whether `getResult` is the default, in case I can&#39;t find the correct element?

I can&#39;t check whether it is `null` or not, because `KeyValuePair` is a struct. 


The default for KeyValuePair

For example, a deployment yaml file:

    apiVersion: extensions/v1beta1
    kind: Deployment
    metadata:
      name: guestbook
    spec:
      replicas: 2
      template:
        metadata:
          labels:
            app: guestbook
          spec:
            container:
              - name: guestbook
                image: {{Here want to read value from config file outside}}

There is a `ConfigMap` feature with Kubernetes, but that&#39;s also write the key/value to the yaml file. Is there a way to set the key to environment variables?

How to set dynamic values with Kubernetes yaml file

I can&#39;t access any cookie from JavaScript. I need to read some value and send them via JSON for my custom checks.

I&#39;ve tried to access cookies from JS, like it was described at:

 - http://www.w3schools.com/js/js_cookies.asp
 - https://stackoverflow.com/questions/10730362/javascript-get-cookie-by-name

As you can see at the code, it&#39;s seen as clear as a crystal the next:

    var c_value = document.cookie;

When I&#39;m trying to access the `document.cookie` value from the Chrome&#39;s web-debugger, I see only the empty string at the **Watch expressions**:

So I can&#39;t read cookies value, which I need.

I&#39;ve checked the cookie name, which I&#39;m sending to get an associated value IS correct.
Also, I&#39;m using the **W3Schools** source code for getting cookies, if you&#39;re interested (but from the 2nd link, the technique is similar).

How can I fix my issue?

Can&#39;t access cookies from document.cookie in JS, but browser shows cookies exist

What is the difference between the following two lines?

    map&lt;int, float&gt; map_data;
    map&lt;const int, float&gt; map_data;


What is difference between const and non const key?

From post:

https://stackoverflow.com/questions/2494294/sending-a-json-array-to-be-received-as-a-dictionarystring-string/7196027#7196027

I’m trying to do this same thing as that post. The only issue is that I don’t know what the keys and the values are upfront. So I need to be able to dynamically add the key and value pairs and I don’t know how to do that.

Does anyone know how to create that object and add key value pairs dynamically?

I’ve tried:

    var vars = [{key:&quot;key&quot;, value:&quot;value&quot;}];
    vars[0].key = &quot;newkey&quot;;
    vars[0].value = &quot;newvalue&quot;;

But that doesn’t work.

How to create dictionary and add key–value pairs dynamically?

Based on an associative array in a Bash script, I need to iterate over it to get the key and value.

    #!/bin/bash
    
    declare -A array
    array[foo]=bar
    array[bar]=foo

I actually don&#39;t understand how to get the key while using a for-in loop.

How to iterate over associative arrays in Bash

I have Go program that has a function defined. I also have a map that should have a key for each function. How can I do that?

I have tried this, but this doesn&#39;t work.
&lt;pre&gt;
func a(param string) {

}

m := map[string] func {
    &#39;a_func&#39;: a,
}

for key, value := range m {
   if key == &#39;a_func&#39; {
    value(param) 
   }
}
&lt;/pre&gt;

Go map of functions

I&#39;d like to create new item that similarly to `Util.Map.Entry` that will contain the structure `key`, `value`.

The problem is that I can&#39;t instantiate a `Map.Entry` because it&#39;s an interface. 

Does anyone know how to create a new generic key/value object for Map.Entry?

Java - How to create new Entry (key, value)

I am trying to make a method that returns a name of a card from my Dictionary
randomly.

My Dictionary: First defined name of the card which is string and second is the value of that card, which is int.

    public static Dictionary&lt;string, int&gt; _dict = new Dictionary&lt;string, int&gt;()
        {
            {&quot;7&quot;, 7 },
            {&quot;8&quot;, 8 },
            {&quot;9&quot;, 9 },
            {&quot;10&quot;, 10 },
            {&quot;J&quot;, 1 },
            {&quot;Q&quot;, 1 },
            {&quot;K&quot;, 2 },
            {&quot;A&quot;, 11 }
        };
Method: 
`random` is a randomly generated int.

        public string getCard(int random)
        {
            return Karta._dict(random);
        }

So the problem is:

&gt;Cannot convert from &#39;int&#39; to &#39;string&#39;

Anybody helps me how should I do it right to get the name?

C# Dictionary get item by index

Hey everyone I&#39;m trying to write a program in Python that acts as a quiz game. I made a dictionary at the beginning of the program that contains the values the user will be quizzed on. Its set up like so:

    PIX0 = {&quot;QVGA&quot;:&quot;320x240&quot;, &quot;VGA&quot;:&quot;640x480&quot;, &quot;SVGA&quot;:&quot;800x600&quot;}

So I defined a function that uses a `for` loop to iterate through the dictionary keys and asks for input from the user, and compares the user input to the value matched with the key.

    for key in PIX0:
        NUM = input(&quot;What is the Resolution of %s?&quot;  % key)
        if NUM == PIX0[key]:
            print (&quot;Nice Job!&quot;)
            count = count + 1
        else:
            print(&quot;I&#39;m sorry but thats wrong. The correct answer was: %s.&quot; % PIX0[key] )

This is working fine output looks like this:

    What is the Resolution of Full HD? 1920x1080
    Nice Job!
    What is the Resolution of VGA? 640x480
    Nice Job!


So what I would like to be able to do is have a separate function that asks the question the other way, providing the user with the resolution numbers and having the user enter the name of the display standard. So I want to make a for loop but I don&#39;t really know how to (or if you even can) iterate over the values in the dictionary and ask the user to input the keys.

I&#39;d like to have output that looks something like this:
    
    Which standard has a resolution of 1920x1080? Full HD
    Nice Job!
    What standard has a resolution of 640x480? VGA
    Nice Job!

I&#39;ve tried playing with `for value in PIX0.values()` and thats allowed me to iterate through the dictionary values, but I don&#39;t know how to use that to &quot;check&quot; the user answers against the dictionary keys. If anyone could help it would be appreciated.

**EDIT:** Sorry I&#39;m using Python3.

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