Questions

How to check if a variable is a dictionary in Python?

How would you check if a variable is a dictionary in Python? For example, I'd like it to loop through the values in the dictionary until it finds a dictionary. Then, loop through the one it finds: ```...

17 Dec at 12:27

Can Android Studio be used to run standard Java projects?

For those times when you want to isolate the Java and give it a quick test.. Can you run non-Android Java projects in Android studio as in Eclipse?

10 Apr at 15:22

How to get list of all installed packages along with version in composer?

I have been working on a project using Symfony 2.1 on my local machine. I have uploaded it to my server but when I try and install the vendor bundles using Composer, I'm getting a lot of dependency e...

1 Nov at 11:1

How to use filter, map, and reduce in Python 3

`filter`, `map`, and `reduce` work perfectly in Python 2. Here is an example: ``` >>> def f(x): return x % 2 != 0 and x % 3 != 0 >>> filter(f, range(2, 25)) [5, 7, 11, 13, 17, 19, 23] >>> de...

Ignoring a class property in Entity Framework 4.1 Code First

My understanding is that the `[NotMapped]` attribute is not available until EF 5 which is currently in CTP so we cannot use it in production. How can I mark properties in EF 4.1 to be ignored? I no...

Sort array of objects by single key with date value

I have an array of objects with several key value pairs, and I need to sort them based on 'updated_at': ``` [ { "updated_at" : "2012-01-01T06:25:24Z", "foo" : "bar" }, { ...

17 Jul at 18:38

What does SQL clause "GROUP BY 1" mean?

Someone sent me a SQL query where the `GROUP BY` clause consisted of the statement: `GROUP BY 1`. This must be a typo right? No column is given the alias 1. What could this mean? Am I right to assume...

12 Sep at 12:16

What's the correct way to convert bytes to a hex string in Python 3?

What's the correct way to convert bytes to a hex string in Python 3? I see claims of a `bytes.hex` method, `bytes.decode` codecs, and have tried [other](http://docs.python.org/py3k/library/functions....

29 Sep at 14:16

How to get MD5 sum of a string using python?

In the [Flickr API docs](http://www.flickr.com/services/api/auth.howto.web.html), you need to find the MD5 sum of a string to generate the `[api_sig]` value. How does one go about generating an MD5 s...

16 Nov at 11:43

How to use putExtra() and getExtra() for string data

Can someone please tell me how exactly to use `getExtra()` and `putExtra()` for intents? Actually I have a string variable, say str, which stores some string data. Now, I want to send this data from o...

14 Oct at 14:37

std::vector versus std::array in C++

What are the difference between a `std::vector` and an `std::array` in C++? When should one be preferred over another? What are the pros and cons of each? All my textbook does is list how they are the...

21 Aug at 09:48

PHP append one array to another (not array_push or +)

How to append one array to another without comparing their keys? ``` $a = array( 'a', 'b' ); $b = array( 'c', 'd' ); ``` At the end it should be: `Array( [0]=>a [1]=>b [2]=>c [3]=>d )` If I use som...

18 Nov at 03:48

Print in one line dynamically

I would like to make several statements that give standard output without seeing newlines in between statements. Specifically, suppose I have: ``` for item in range(1,100): print item ``` The ...

6 Aug at 18:14

Detect changes in the DOM

I want to execute a function when some div or input are added to the html. Is this possible? For example, a text input is added, then the function should be called.

Is recursion ever faster than looping?

I know that recursion is sometimes a lot cleaner than looping, and I'm not asking anything about when I should use recursion over iteration, I know there are lots of questions about that already. Wha...

25 Oct at 00:32

Update statement with inner join on Oracle

I have a query which works fine in MySQL, but when I run it on Oracle I get the following error: > SQL Error: ORA-00933: SQL command not properly ended 00933. 00000 - "SQL command not properly end...

20 Nov at 09:39

What is the difference between the dot (.) operator and -> in C++?

What is the difference between the dot (.) operator and -> in C++?

1 Sep at 07:25

How can I reverse a NSArray in Objective-C?

I need to reverse my `NSArray`. As an example: `[1,2,3,4,5]` must become: `[5,4,3,2,1]` What is the best way to achieve this?

30 Jun at 18:16

Is there a way to force npm to generate package-lock.json?

I deleted it by accident and have made many changes to `package.json` since. An `npm install` or `npm update` do not generate `package-lock.json` anymore. I tried clearing my npm cache and my nvm cach...

10 Jun at 18:41

Format date as dd/MM/yyyy using pipes

I'm using the `date` pipe to format my date, but I just can't get the exact format I want without a workaround. Am I understanding pipes wrongly or is just not possible? ``` //our root app component ...

2 Nov at 22:40

Pandas DataFrame to List of Dictionaries

I have the following DataFrame: which I want to translate it to list of dictionaries per row ``` rows = [ { 'customer': 1, 'item1': 'apple', 'item2': 'milk', 'item...

How do I check when a UITextField changes?

I am trying to check when a text field changes, equivalent too the function used for textView - `textViewDidChange` so far I have done this: ``` func textFieldDidBeginEditing(textField: UITextField)...

27 Sep at 10:16

Pandas Replace NaN with blank/empty string

I have a Pandas Dataframe as shown below: ``` 1 2 3 0 a NaN read 1 b l unread 2 c NaN read ``` I want to remove the NaN values with an empty string so that it looks like ...

20 Oct at 20:38

Using Pandas to pd.read_excel() for multiple worksheets of the same workbook

I have a large spreadsheet file (.xlsx) that I'm processing using python pandas. It happens that I need data from two tabs (sheets) in that large file. One of the tabs has a ton of data and the other ...

1 Aug at 22:34

How to select a single field for all documents in a MongoDB collection?

In my MongoDB, I have a student collection with 10 records having fields `name` and `roll`. One record of this collection is: ``` { "_id" : ObjectId("53d9feff55d6b4dd1171dd9e"), "name" : "Sw...

18 Feb at 11:54