Data Entry Programming Challenge (Python)
The challenge: My Solution:
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HTML Tags
<html> -- All code enclosed within these tags is interpreted as HTML. <body> -- Defines the content in the main browser content area. <head> -- Defines the browser tab or windows heading area. <title> -- Defines the text that appears with the tab or window heading area. <h1>, <h2>, <h3> -- Heading styles in decreasing sizes. <p> A paragraph separated with a line space above and below. <img> Self closing image tag with parameters: <img src = location, height=x, width=y> <a> -- Anchor tag defining a hyperlink with location parameter: <a href="location"> Link Text </a> <ol>, <ul> -- Defines an ordered (numbered) or unordered (bulleted) list. <li> -- Defines an individual list item within either a numbered or bulleted list.
Webforms & JavaScript
Webforms enable websites to collect information (input) that are user enters. inputs can be text, numbers, checkboxes, drop-downs etc. Inputs can be added to a website database or be used in a search of a database. Web forms can be created very easily in HTML, once actions are applied within the HTML code the form will work with basic functionality. JavaScript is used to add behaviours to a webpage, such as formatting and change of colours. They can be used within web forms to make areas change colour as a user inputs invalid or no data for example, eg: Incorrect Password [box highlighted red]. Inactive Web Form (coded in HTML). Active Web Form (coded in HTML, JavaScript). JavaScript was most commonly found on the web in forms that included Captcha security etc. Although the new Captcha system most commonly used now uses HTML 5, something which is largely replacing JavaScript. When being ran, JavaScript is interpreted rather than being compiled. This i...
Programming Constructs
Programming consists of three basic programming constructs: - Branching/Selection, eg: IF statements. - Iteration Statements, eg: FOR or WHILE loops. - Sequences, eg: program that is written in the order that things happen when it is executed. Most Python programs are written like this.
Assembly Language
Machine code (0s and 1s) was used by early programmers. This was incredibly complicated and time consuming. To the next advance in programming was the use of mnemonics. This is assembly code. Mnemonics are short words that represent an action in a computer program. One mnemonic translates into one machine code instruction. Assembly code is still very basic but is much easier to understand then binary. The assembler translates assembly code into machine code. Assembly code is as follows:
OSI Network Model
Open Systems Interconnection (OSI) model - a conceptual framework that describes the functions of a networking or telecommunication system. The OSI model has 7 layers. Layer 7 - Application Layer This is what the user communicates with. It is the applications that we used - Google Chrome & Skype are examples. Layer 6 - Presentation This is where data is converted from the application framework into something that the network understand. The data would be encrypted here for example. Layer 5 - Session Computer need to create a session between the two devices so they can speak to each other. This is done here. The computer communicate telling each other how much time they should wait for a response from each other and what they should do when the task has been completed (end session) etc. Layer 4 - Transport The Transport Layer deals with the coordination of the data transfer between end systems and hosts. This...
Other Network Protocols
FTP - Tranferring Files Used to transfer files across a network or the internet. It is a high level protocol found in the application layer. E.g: A worker uploads a file from there computer (client) to the FTP server. This can then be accessed by co-worker as they can see a 'shared folder' on the server. Receiving and Sending emails A mail server acts as a 'post office' for emails. It directs mail based on a database of all the local email addresses. The mail is then held until the user retrieves it (a bit like a American post box). POP3 - Emails are temporarily stored on the server. When the client computer accesses the email it gets downloaded to there computer and deleted from the server. The problem with this is that emails will only sync to one device, not multiple. IMAP - Emails are stored on a server and synced between devices. Any change on one device will appear on another device. This is how most modern email accounts work. SMTP - Transfers emai...
TCP/IP Protocol (Packet Layers)
When data is being transmitted through a network the following process is used (TCP/IP): Application Layer - This is the top layer of TCP/IP protocol suite. This layer includes applications or processes that use transport layer protocols to deliver the data to destination computers. Each different piece of software uses a different protocol so the correct one is selected. The most common types of protocol used are: HTTP (Hypertext transfer protocol) FTP (File transfer protocol) SMTP (Simple mail transfer protocol) Transport Layer - divides the data (coming from the application layer) into proper sized chunks and then passes these chunks onto the network (packets). It acknowledges received packets, waits for the acknowledgments of the packets it sent and sets timeout to resend the packets if acknowledgements are not received in time. The term ‘reliable connection’ is used where it is not desired to loose any information that is being transfer...
Types of Switching (Data Transmission)
Circuit Switching Creates a direct link between two devices for the duration of communication. Example is a telephone system. If you are calling somebody on your mobile and somebody tries to ring you they will get a 'user is unavailable message'. This is because when a call is made a direct path in a telephone exchange is made by various switches. Advantages of this is that it is quick (no delay) as there is no interference and also the fact that it is simple to set up. Only two people are using the connection at once, everyone else would be rejected. Disadvantage is that only one connection can be made at once, group calls are multiple calls on one line aren't possible. Also it wastes a lot of bandwidth, even if a person is on hold the line is still in use/data being sent so no one else could use it. It is important with Circuit Switching that data is sent/received at the same rate otherwise there will be delays/pauses in the call. Data always arrives in the ord...