Tutorial by Examples: le

Deletes all documents matching the query parameter: // New in MongoDB 3.2 db.people.deleteMany({name: 'Tom'}) // All versions db.people.remove({name: 'Tom'}) Or just one // New in MongoDB 3.2 db.people.deleteOne({name: 'Tom'}) // All versions db.people.remove({name: 'Tom'}, true) M...

One common use case for generators is reading a file from disk and iterating over its contents. Below is a class that allows you to iterate over a CSV file. The memory usage for this script is very predictable, and will not fluctuate depending on the size of the CSV file. <?php class CsvReade...

The AppCompat Support Library defines several useful styles for Buttons, each of which extend a base Widget.AppCompat.Button style that is applied to all buttons by default if you are using an AppCompat theme. This style helps ensure that all buttons look the same by default following the Material D...

If you want to include PHP code in your HTML file and you don't want to rename the file type from .html or .htm to .php, the below allows your HTML file to parse your PHP code correctly. AddHandler application/x-httpd-php .html .htm

Implementing IErrorHandler for WCF services is a great way to centralize error handling and logging. The implementation shown here should catch any unhandled exception that is thrown as a result of a call to one of your WCF services. Also shown in this example is how to return a custom object, and h...

/// <summary> /// Returns the data for the specified ID and timestamp. /// </summary> /// <param name="id">The ID for which to get data. </param> /// <param name="time">The DateTime for which to get data. </param> /// <returns>A Data...

php artisan route:list --method=GET --method=POST This will include all routes that accept GET and POST methods simultaneously.

Horizontally vim -o file1.txt file2.txt Vertically vim -O file1.txt file2.txt You may optionally specify the number of splits to open. The following example opens two horizontal splits and loads file3.txt in a buffer: vim -o2 file1.txt file2.txt file3.txt

A while loop will cause the loop statements to be executed until the loop condition is falsey. The following code will execute the loop statements a total of 4 times. i = 0 while i < 4: #loop statements i = i + 1 While the above loop can easily be translated into a more elegant fo...

Sometimes, you may want something to occur regardless of whatever exception happened, for example, if you have to clean up some resources. The finally block of a try clause will happen regardless of whether any exceptions were raised. resource = allocate_some_expensive_resource() try: do_stu...

While reading content from a file is already asynchronous using the fs.readFile() method, sometimes we want to get the data in a Stream versus in a simple callback. This allows us to pipe this data to other locations or to process it as it comes in versus all at once at the end. const fs = require(...

To find some number (more than one) of largest or smallest values of an iterable, you can use the nlargest and nsmallest of the heapq module: import heapq # get 5 largest items from the range heapq.nlargest(5, range(10)) # Output: [9, 8, 7, 6, 5] heapq.nsmallest(5, range(10)) # Output: [...

Here is a full Activity class that places a Marker at the current location, and also moves the camera to the current position. There are a few thing going on in sequence here: Check Location permission Once Location permission is granted, call setMyLocationEnabled(), build the GoogleApiClient, ...

You can create one table from another by adding a SELECT statement at the end of the CREATE TABLE statement: CREATE TABLE stack ( id_user INT, username VARCHAR(30), password VARCHAR(30) ); Create a table in the same database: -- create a table from another table in the same data...

Variables of character type or of a derived type with length parameter may have the length parameter either assumed or deferred. The character variable name character(len=len) name is of length len throughout execution. Conversely the length specifier may be either character(len=*) ... ! Ass...

import pandas as pd import numpy as np np.random.seed(123) x = np.random.standard_normal(4) y = range(4) df = pd.DataFrame({'X':x, 'Y':y}) >>> df X Y 0 -1.085631 0 1 0.997345 1 2 0.282978 2 3 -1.506295 3

A select case construct conditionally executes one block of constructs or statements depending on the value of a scalar expression in a select case statement. This control construct can be considered as a replacement for computed goto. [name:] SELECT CASE (expr) [CASE (case-value [, case-value] .....

You can create a DataFrame from a list of simple tuples, and can even choose the specific elements of the tuples you want to use. Here we will create a DataFrame using all of the data in each tuple except for the last element. import pandas as pd data = [ ('p1', 't1', 1, 2), ('p1', 't2', 3, 4)...

if ([object respondsToSelector:@selector(someOptionalMethodInProtocol:)]) { [object someOptionalMethodInProtocol:argument]; }

Every authenticated user has a Firebase uid that's unique across all providers and is returned in the result of every authentication method. A good way to store your user's data is to create a node to keep all the users's data and to protect it using your security rules - Database { "use...