Angular services are used to organize code across the application and are wired together using Dependancy Injection. Angular services are lazily instantiated, i.e, they are instantiated only when an application component depends on it.They are singletons, ie there will be only one instance exists for the app and the components depending on the service gets the reference to the service.
Perl is an object oriented language. Perl has packages(class) that could be instanciated and used. At first, we need to decide the file namefor the package ans the perl class name carries the file name. For example, a package
Student should be in the file
Student.pm. If it shouldbe called
Bright::Student, it should be saved as
Student.pm in a directory named
Bright. There is no formal relationship between directory name and modules. That is just grouping for convenience.
With Net:FTP for uplink and downlink file transfers, we may have problems with obtaining the same statistics that are provided by ftp when you perform a manual transfer, i.e file size, transfer duration and transfer speed in KBs. The easiest solution is to print the
$ftp->message; It contain some message. For example,
Amazon S3 is an efficient static file storage system for its services and relatively cheap. On the other hand Django is a nice web development framework that doesn't like to handle static files. Mezzanine is a popular blog engine built in Django. Since Django doesn't like to handle static files on production systems, we always have to configure a web server like nginx or apache webserver to serve static files. On the other hand, its easy to host static files to Amazon S3. The S3 configuration for static files is easy, but saving user uploaded files for Django web app may raise some permission issues. Here is how we have configured the Django-S3-Mezzanine blog.
Python has already gained it's momentum among IoT developers as it offers readability with syntax without compromising on syntax. In today's era, language doesn't really matter any more when it comes to IoT, ease of writing the code efficiently matter. Large number of available open-source libraries and ability to get more things done with fewer lines of code is an added plus. Python's clean syntax and one to one mapping of it's data built-in structure -dict- to JSON are added advantages. If your application works with database or communicates with JSON data, Python is the right choice. Python is the choice of language for Raspberry Pi, one of the most popular micro controllers in the market. The micro Python is another micro controller optimized for using Python. Few of the advantages of using python includes
We often needto sort a list of dictionaries by calculated value. Python's sorted is very powerful so that it can do literally anything with custom key function Assume that we have a list of 20 students with their name and marks. Wedont have the total of their marksin the list. We want to sort them by rank, ie descending order of total marks.
One of the cases we face in programming is sorting an array of dictionaries by value in the dictionary. In Python, it is possible to write a one-liner to achive the same. Suppose we have a
dictwith name and age of students in a class.
Python dictionaries are key-value pairs. Some times we need to sort the dictionary by key or by value. In both cases we can do it by using the built in sorted function.