Skip to main content

Python - Use of Assert Keyword

🐍 Assert keyword simply checks if a condition returns true or false. It is a short for writing if statement to check if something is true or false.

Syntax

assert <condition>, <optional message>

Optional message in the syntax is optional. It is displayed in the error when the condition is false. When the condition is false, the code will also not proceed any further. It ends the program there and returns and error with the message, if it is mentioned.

Example

assert 25%2==0, 'Add 1 to the number'

Comments

Popular posts from this blog

Python - List - Append, Count, Extend, Index, Insert, Pop, Remove, Reverse, Sort

🐍 Advance List List is widely used and it's functionalities are heavily useful. Append Adds one element at the end of the list. Syntax list1.append(value) Input l1 = [1, 2, 3] l1.append(4) l1 Output [1, 2, 3, 4] append can be used to add any datatype in a list. It can even add list inside list. Caution: Append does not return anything. It just appends the list. Count .count(value) counts the number of occurrences of an element in the list. Syntax list1.count(value) Input l1 = [1, 2, 3, 4, 3] l1.count(3) Output 2 It returns 0 if the value is not found in the list. Extend .count(value) counts the number of occurrences of an element in the list. Syntax list1.extend(list) Input l1 = [1, 2, 3] l1.extend([4, 5]) Output [1, 2, 3, 4, 5] If we use append, entire list will be added to the first list like one element. Extend, i nstead of considering a list as one element, it joins the two lists one after other. Append works in the following way. Input l1 = [1, 2, 3] l1.append([4, 5]) Output...

Difference between .exec() and .execPopulate() in Mongoose?

Here I answer what is the difference between .exec() and .execPopulate() in Mongoose? .exec() is used with a query while .execPopulate() is used with a document Syntax for .exec() is as follows: Model.query() . populate ( 'field' ) . exec () // returns promise . then ( function ( document ) { console . log ( document ); }); Syntax for .execPopulate() is as follows: fetchedDocument . populate ( 'field' ) . execPopulate () // returns promise . then ( function ( document ) { console . log ( document ); }); When working with individual document use .execPopulate(), for model query use .exec(). Both returns a promise. One can do without .exec() or .execPopulate() but then has to pass a callback in populate.

Resolve: Uncaught TypeError: firebase.database is not a function

If you are getting the error: Uncaught TypeError: firebase.database is not a function Resolve it by including firebase-database.js in your html page as follows: <!-- The core Firebase JS SDK is always required and must be listed first --> <script defer src = "https://www.gstatic.com/firebasejs/6.2.4/firebase-app.js" ></script> <script defer src = "https://www.gstatic.com/firebasejs/3.1.0/firebase-database.js" ></script> That is it. Let me know if this was helpful.