Learn about different types of tools used in the data analysis process including data visualisation, data cleaning and GIS. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 3.5 - Data Analysis Tools Exam Board: OCR Specification: 2016 - Unit 2 The fifth stage of data analysis is to select the most appropriate tools to analyse the collected data. The method(s) selected will depend on the type of project and the established objectives. Data Tables Databases are often split into tables to be easier to update , view and manipulate . For example, a supermarket database may include a table of product information, another table of suppliers and another for actual stock levels. Separating the data into tables allows for simpler editing and also allows for the display of basic patterns . For example, looking at a table of stock levels in a supermarket can quickly show which products need to be ordered in as they are close to selling out. Data tables allow for the most simple form of pattern discovery and are a good method of speedy, short-term data analysis . However they present data in its current format and cannot show change or trends over time - a product may have a high stock level because it is popular and has just been ordered in, rather than because no-one is buying it. A simplified data table for a supermarket. Visualisation of Data Visualising data (by producing a chart or graph of collected data for example) makes it easier for an audience to see trends and patterns . Visualising data, like the bar chart to the right of the supermarket table from the tool above, makes it easier to understand and quicker to interpret . In this example, It is easier to see using the chart that steak pies are low in stock and should be re-ordered soon. A bar chart of the supermarket data table. Trend & Pattern Identification This tool links heavily to visualisation of data in allowing trends and patterns to be viewed as a visual format - such as producing a line graph of last year’s stock sales. Statistical analysis allows data analysts to examine numerical data and, if done correctly, can highlight relationships between different data elements - such as the price of a product and how many have been sold. Discovering links between variables is known as regression analysis . Data Cleaning Data cleaning ensures that any stored data is up-to-date and accurate , in accordance with the Data Protection Act ( 2018 ). Forms of data cleaning include removing customers who have not made a purchase in a certain amount of time (e.g. two years) and periodically checking that user addresses are up to date. Data cleaning would reduce the size of any data table by removing redundant, incorrect or unnecessary data . This would make it easier to work with the data table and would improve the data quality by removing erroneous and irrelevant data. GIS / Location Mapping Geographic Information Systems (GIS ) can be used to add geographic data to any analysis. For example, an organisation can track the geographical location of items or staff e.g. tracking the movement of shipping containers around the world to see production flow. This also works for courier services to see delays and delivery times in real-time . Q uesto's Q uestions 3.5 - Data Analysis Tools: 1. Describe how Fresh Food UK, from the question in 3.4 , could use each of the data analysis tools when trying to determine and present the most profitable stores across the country in the past year . a. Data Tables [3 ] b. Visualisation of Data [3 ] c. Trend & Pattern Identification [3 ] d. Data Cleaning [3 ] e. GIS / Location Mapping [3 ] 3.4 - Stages of Data Analysis Topic List 3.6 - Information Systems

Learn about the different phases in software development models including planning, requirements, feasibility, design, construction / creation, testing, implementation (phased / parallel / big bang (crash)), documentation creation and maintenance. Based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) (AAQ - Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 2.2 - Phases of Software Development Models Watch on YouTube : Phases of Software Development Models There are seven phases of software development models you need to know. As well as knowing the common phases and the key tasks within each phase , you must also understand how and why phases interact with each other and why they may iterate . Phases of Software Development Models Key Phases Planning (including requirements and feasibility ) Design Construction / Creation Testing Implementation (including phased , parallel and big bang ( crash ) methods) Maintenance Documentation creation Phased Parallel Big Bang Q uesto's Q uestions 2.2 - Phases of Software Development Models: 1. Describe the common tasks in each of the first four phases of software development . [8 ] 2. Explain the three implementation methods : phased , parallel and big bang (crash ). [6 ] 3. Describe the common tasks in the final two phases . [4 ] 4. Explain why it is important that phases interact with each other. [ 2 ] Maintenance is important - as of 2025 , some US air traffic control towers still use and maintain systems using Windows 95 and floppy disks because of their reliability . D id Y ou K now? 2.1 - Software Development Models Topic List 3.1 - Planning Projects

Learn about the devices used to host applications, including consoles, desktops, haptics, laptops, servers, smart devices, tablets / hybrid devices and wearables. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 1.2 - Devices Watch on YouTube : Devices You need to know the characteristics of the eight types of devices shown below that application platforms run on . You must also understand the advantages and disadvantages of each device . What You Need to Know Devices Game consoles are designed specifically for playing video games , usually connected to a TV . Desktops are powerful and customisable personal computers designed for use at a desk . Haptic devices allow users to feel vibrations with touch . Game controllers and smartphones use haptics. Laptops are portable computers with a built-in screen and keyboard , suitable for work on the go . Servers are powerful computers on a network that process requests sent by other systems. Smart devices connect to a network allowing it to communicate with other devices and be controlled remotely . Tablets use a large touchscreen and are more portable than a laptop , ideal for browsing and media . A hybrid device is a laptop with a detachable screen . Wearable devices such as a smartwatch are worn on the body and often monitor the user's condition in real-time . Q uesto's Q uestions 1.2 - Devices: 1. Choose the most appropriate device and explain your answer. [3 each ] a. A graphic designer needs maximum performance and wants to upgrade components over time . b. A student needs a computer to take to lessons and complete homework . c. A hospital wants to provide files and applications to hundreds of staff members . d. A gamer wants the easiest and cheapest way to play the latest games . e. An engineer is designing a virtual reality training simulation . f. A fitness enthusiast wants to track their heart rate and daily exercise . g. A salesperson needs a lightweight device for presentations and note-taking . h. A family wants a device for watching movies and using apps around the house . 2. Compare the following pairs . For each comparison , explain one similarity , two differences and which you would recommend for a given purpose. [ 4 each ] a. Desktop vs Laptop b. Laptop vs Tablet/Hybrid c. Console vs Desktop d. Smart Device vs Wearable Check out the Shorts on the CSNewbs YouTube channel if you are interested in how video game consoles have evolved over time . There are separate videos for PlayStation , Xbox and Nintendo consoles. D id Y ou K now? 1.1 - Application Platforms Topic List 1.3 - Storage Locations

Learn about how to perform binary addition and binary shifts. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 2.4b: Binary Addition & Shifts Exam Board: OCR Specification: J277 Watch on YouTube : Binary Addition Overflow Errors Binary Shifts Issues with Shifts Binary Addition Binary addition is a method of adding binary values without having to convert them into denary. How to add binary numbers: What is an overflow error? An overflow error occurs when a binary value is too large to be stored in the bits available . With a byte (8 bits ) the largest number that can be held is 255 . Therefore any sum of two binary numbers that is greater than 255 will result in an overflow error as it is too large to be held in 8 bits . What is binary shift? Binary shift is used to multiply and divide binary numbers . The effect of shifting left is to multiply a binary number. The effect is doubled by each place that is shifted . x The effect of shifting right is to divide a binary number. ÷ Shifting by 1 has an effect of 2 . Shifting by 2 has an effect of 4 . Shifting by 3 has an effect of 8 . For example, shifting left by 2 places has an effect of multiplying by 4 . Another example: Shifting right by 3 places has an effect of diving by 8 . How to shift a binary number: Binary Shifts Watch on YouTube Watch on YouTube Q uesto's Q uestions Binary Addition: 1. Explain what an overflow error is. [ 2 ] 2. Add together the following binary values. If an overflow error occurs you must state one has occurred. a. 010110012 and 010001012 [2 ] b. 110110112 and 010111012 [2 ] c. 001101102 and 011010112 [2 ] d. 110110112 and 010101112 [2 ] e. 011011012 and 110101102 [2 ] Binary Shifts: 1a. Draw a diagram to show the effect of multiplying and dividing a binary number . [2 ] 1b. Draw a diagram or table to show the effect a shift has for each place from 1 to 4 . For example, a shift of 1 place has an effect of 2. [4 ] 2. State the effect of the following shifts: a. Shift right by 2 places. b. Shift left by 1 place. c. Shift left 3 places. d. Shift right by 4 places. [ 1 each ] 3. Shift the following binary numbers and state the effect of the shift: a. 10101011 : Shift left by 2 places. b. 11101100 : Shift right by 3 places. c. 00001011 : Shift right by 2 places. d. 01101110 : Shift left by 1 place. [ 2 each ] 2.4a - Number Systems Theory Topics 2.4c - Character Storage

Learn about the advantages and disadvantages of networks, the five types of network - LAN, WAN, PAN, MAN and VPN - and differences between wired and wireless networks. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.1: Network Characteristics Exam Board: Eduqas Specification: 2020 What is a network? A network is more than one computer system connected together allowing for communication and sharing of resources . There are many benefits but also some drawbacks to using a network compared to having an unconnected ('standalone' ) computer: Advantages of Networks Easily share files , software and hardware between computers. Disadvantages of Networks There is an initial cost because network devices like routers are required . Larger companies will need to buy and maintain a server . Log in from any connected computer and access your data and files. A network manager / administrator might need to be employed to maintain the network . An administrator can monitor network activity and control security settings. Data from computers on the network can be automatically backed up on central storage. Security breaches are more likely and malware , such as worms, can spread quickly across the network. If the web server fails , all connected computers won't be able to access files or log on . Network Types Networks can be split into different types , usually categorised by their geographical distance apart and the area that they serve. Local Area Network A local area network (LAN ) has computer systems situated geographically close together , usually within the same building or small site , like a school or office . Wide Area Network A wide area network (WAN ) has computer systems situated geographically distant to each other, possibly across a country or even across the world . The internet is an example of a WAN that spans the globe. Personal Area Network A PAN is a personal network for an individual , such as a photographer connecting a smartphone, desktop computer and printer together. Metropolitan Area Network A MAN is larger than a LAN but smaller than a WAN and typically covers a relatively large area like a university campus, town or city . Virtual Private Network A VPN allows for a secure and encrypted connection to a public network like the internet. It is often used to protect an individual's privacy by concealing their real location. Wired & Wireless Networks Wired Connections Wireless Connections Wireless connections, such as WiFi or Bluetooth , use no cables but require a wireless network interface card (WNIC ). Wireless connections generally have a slower speed and can be affected by the computer's distance from the wireless router as well as obstacles like walls or bad weather. Wired connections use physical cables , such as copper or fibre optic wires , and require a network interface card (NIC ) to connect to a network. These wired connections use a wired connection protocol - most commonly Ethernet . Restricted Movement Faster More Secure NIC Required Freedom of Movement Slower Less Secure WNIC Required Q uesto's Q uestions 3.1 - Network Characteristics: 1. A retirement home for the elderly is considering installing a LAN , give 3 benefits and 3 drawbacks they might find of using a network . [6 ] 2a. Describe the difference between a LAN and WAN . [2 ] 2b. Give an example of how a LAN and a WAN could each be used . [ 2 ] 3 . Explain the differences between a PAN , MAN and VPN . [ 3 ] 4. For each of the scenarios below, state which network type would be most suitable : a. The IT rooms of a secondary school . [ 1 ] b. A study in a house with a desktop and printer. [ 1 ] c. Using online banking when abroad on a holiday to stay secure . [ 1 ] d. A large technology company with offices across Europe . [ 1 ] e. Council offices with several locations across Manchester . [ 1 ] 5. Briefly compare wired and wireless networks . [ 8 ] 2.2 - Boolean Algebra 3.2 - Data Packets & Switching Theory Topics

Explains the components of the CPU, the different registers, buses, how the FDE cycle works, CPU performance factors, pipelining, Von Neumann architecture and Harvard architecture. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 1.1 - Structure and Function of the Processor Specification: Computer Science H446 Watch on YouTube : CPU components Registers Buses The FDE cycle CPU performance Pipelining Von Neumann vs Harvard Contemporary architecture The Central Processing Unit ( CPU ) is the most important component in every computer system. The purpose of the CPU is to process data and instructions by constantly repeating the fetch-decode-execute cycle . In this cycle, instructions are fetched from RAM and transferred into the registers of the CPU to be decoded and executed . CPU Components The CPU has three key components : The control unit directs the flow of data and instructions inside the CPU and manages the FDE cycle , especially decoding instructions . The arithmetic logic unit ( ALU ) performs all arithmetic calculations and logical operations inside the CPU . Registers are small , ultra-fast storage locations that temporarily hold data , instructions or addresses during processing . The CPU also contains cache memory , which is temporary storage space for frequently accessed data . Registers A register is a small storage space for temporary data , instructions or addresses in the CPU . Each register has a specific role in the FDE cycle : The Program Counter ( PC ) stores the memory address of the next instruction to be fetched from RAM . The Memory Address Register ( MAR ) stores the memory address currently being accessed , which may be an instruction or data . The Memory Data Register ( MDR ) stores the data that is transferred from RAM to the CPU . The Current Instruction Register ( CIR ) stores the instruction that has been fetched from RAM . The Accumulator ( ACC ) stores data currently being processed and the result of calculations or logical operations made by the ALU . Buses Data and signals are transmitted between components across internal connections called buses . There are three types of computer bus : The data bus transmits data and instructions between the CPU , memory and other components such as input/output devices . It is bidirectional (data is sent both ways ). The address bus transmits the location in memory that the CPU is accessing . It is unidirectional (one-way ) from the CPU to RAM . The control bus transmits control signals (e.g. 'read ' or 'write ') from the CPU to coordinate other components . It is bidirectional . The FDE Cycle In the Fetch Decode Execute (FDE ) cycle , instructions are fetched from RAM , then decoded (understood) and executed (processed) in the CPU . This cycle is performed by the CPU millions of times every second using the registers and buses explained above. This cycle is how the CPU processes data and instructions for each program or service that requires its attention . CPU Performance The performance of the CPU is affected by three main factors : Clock speed is t he number of cycles per second , so a higher clock speed means more instructions can be executed per second . The number of cores is important as more cores allow a CPU to carry out multiple instructions simultaneously , improving multitasking and parallel processing . Cache memory is small and very fast memory inside the CPU that stores frequently used instructions , reducing the time needed to access RAM . Pipelining Pipelining is the concurrent processing of multiple instructions . An instruction can be fetched while another is decoded and another is executed . This overlapping of instructions increases the overall speed of program execution . Computer Architecture Computer architecture refers to the design and organisation of a system’s components and how they interact . There are two types of architecture to know: Von Neumann architecture uses a single main memory (RAM ) that stores both program instructions and data . This means instructions and data travel along the same buses , which can cause a bottleneck (congestion ). Harvard architecture separates the storage of program instructions and data into two different memory locations . This allows instructions and data to be fetched at the same time , improving performance . You also need to know about c ontemporary (modern) architecture , which includes features such as onboard ( integrated ) graphics , performance boosting mode , out-of-order execution and virtual cores . Q uesto's K ey T erms Components of the CPU: control unit (CU), arithmetic logic unit (ALU), registers, cache memory Registers: program counter (PC), memory address register (MAR), memory data register (MAR), current instruction register ( CIR), accumulator (ACC) Buses: data bus, address bus, control bus, unidirectional, bidirectional FDE Cycle: fetch stage, decode stage, execute stage CPU Performance: clock speed , number of cores , cache memory Pipelining: pipelining Computer architecture: Von Neumann, Harvard, contemporary D id Y ou K now? The Apollo Guidance Computer ( AGC ) for NASA's Apollo 11 mission , when humans first set foot on the moon , had a CPU clock speed of about 1 megahertz - slower than many GCSE-level calculators used today. A-Level Topics 1.2 - Types of Processor

Learn how to set up a brand new HTML page using Notepad ++. Find out how to format the document ready for tags to be entered. 1. Setting up a HTML document HTML Guide Watch on YouTube: This guide assumes that you have Notepad++ already installed. If you are working at home and need to download Notepad++ then click here . Save as .html file Notepad++ assumes you are writing a text file so you must change the file type . Open Notepad++ Click File then Save As... Change Save as type: from Normal text file (.txt) to Hyper Text Markup Language file (.html) Change File name: to Fanpage Website.html These steps are necessary to set up your HTML web page correctly. Open Notepad ++ and save your file as a .html document. Editor vs. Browser View In newer versions of Notepad++ click on View then View Current File in and choose a browser installed on your computer such as Chrome . Some versions of Notepad++ enable you to view the document in a web browser by selecting Run then an option such as Launch in Chrome . It is good practice to have both Notepad++ and a web browser open at the same time so that you can easily check if any changes have been made correctly. Remember to press the save icon ( ) before you refresh your browser . Don't expect your web browser to show anything yet. Next it is time to add our essential tags for the structure of the web page. HTML Guide 2. Essential Tags

Learn about the three types of translators - assemblers, interpreters and compilers. Also, understand the differences between compilers and interpreters. Based on the 2020 Eduqas (WJEC) GCSE specification. 10.1: Translators Exam Board: Eduqas Specification: 2020 What is a translator? A translator changes (translates) a program written in one language into another language (usually machine code ). There are three types of translator : Assembler An assembler converts low level assembly language into machine code . INP STA 33 INP STA 34 LDA 33 ADD OUT HLT Interpreter An interpreter converts high-level language one line at a time into machine code and executes it. PYT HON Compiler A compiler converts high-level language into machine code for execution at a later time. The entire program is converted at once . PYT HON 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 Differences between an interpreter and a Compiler: Interpreter Compiler Execution Method: An interpreter translates source code (high level code) into machine code one line at a time . Execution Speed: An interpreter is slower than a compiler because the code must be reinterpreted each time the program is run. Complexity: Interpreters are smaller, simpler programs . Error Reporting: In error reporting, the interpreter would encounter the errors and report it to the user immediately and stops the program from running. Repetition: Interpreted programs can be edited and run without translating the whole program . Interpreters must reinterpret the program every time it is run. Execution Method: A compiler translates all the source code (high level code) into machine code in one go . A compiler produces an executable file that will run on other machines without the compiler needing to be installed. Execution Speed: Compilers can produce much more efficient code than interpreters making the compiled programs run faster . Complexity: Compilers tend to be large complex programs . Error Reporting: The compiler would analyse the entire program , taking note of where errors have occurred and record them in an error file . Repetition: Compilation requires analysis and the generation of the code only once , whereas interpreters must re-interpret each time. However, compiled programs have to be re-compiled after any changes have been made. x1 ∞ x1 Q uesto's Q uestions 10.1 - Translators: 1. Briefly describe each type of translator : a. Assembler [ 1 ] b. Interpreter [ 2 ] c. Compiler [ 2 ] 2. Compare interpreters and compilers for each of the following features : a. Execution Method b. Execution Speed c. Complexity d. Error Reporting e. Repetition [ 10 total ] 9.1 - IDE Tools Theory Topics 10.2 - Stages of Compilation

Learn database topics including entity relationships, keys, normalisation, capturing and exchanging data, SQL, referential integrity, transaction processing and ACID (atomicity, consistency, isolation, durability). Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 3.2 - Databases Specification: Computer Science H446 Database Key Terms A database is an organised collection of data stored in tables , where each table represents an entity such as a customer or product . Each table is made up of records ( rows ), which store information about individual instances of that entity , and fields ( columns ), which hold specific attributes like names or prices . A primary key uniquely identifies each record , while a foreign key links records between tables to create relationships . Secondary keys use indexing to speed up searches and data retrieval . A flat file database stores all data in a single table or file , often in a simple format such as a spreadsheet or text file . It is easy to create and manage , making it suitable for small-scale applications . However, it can lead to data duplication and inconsistency because the same data may be repeated in multiple records . A relational database stores data in multiple related tables , linked together using primary and foreign keys . This design reduces data redundancy and improves data integrity by storing each piece of information only once . The main disadvantage is that relational databases are more complex to design and maintain , requiring more processing power and knowledge to manage effectively . ER Diagrams Relationships between entities are shown using an Entity–Relationship ( ER ) diagram , which illustrates connections between tables in a visual format . There are three types : many-to-many (e.g. Students to Teachers ) Capturing & Managing Data Data can be captured from sources such as forms , Optical Character Recognition (OCR ), Optical Mark Recognition (OMR ) and sensors . These methods allow information to be collected automatically or manually and entered into a computer system for processing . Data can be selected and filtered using tools like Query By Example (QBE ) or SQL commands . This allows users to retrieve only the specific records that meet certain criteria from a database . Data management involves manipulating stored information , such as performing arithmetic functions or adding , editing and deleting records . This ensures that the data remains accurate , up to date and useful for decision-making . Data can be exchanged (shared ) between systems using common file formats such as CSV and JSON . These formats make it easier to transfer data between different software applications or platforms while maintaining structure and meaning . Database Normalisation Database normalisation is the process of organising data in a database to reduce redundancy and improve data integrity . It ensures that each piece of data is stored only once , making updates and maintenance more efficient and reducing the risk of inconsistent data . Normalisation is measured in 'forms ': First Normal Form (1NF ): Ensures that all fields contain atomic (indivisible ) values and that there are no repeating groups in a table. Each table must have a primary key . Second Normal Form (2NF ): Builds on 1NF by ensuring that all non-key attributes depend on the entire primary key , removing partial dependencies . Third Normal Form (3NF ): Builds on 2NF by removing transitive dependencies , meaning non-key attributes depend only on the primary key and not on other non-key attributes . Flat File & Relational Databases one-to-one (e.g. Students to Lockers ) one-to-many (e.g. Tutor Group to Students ) Structured Query Language (SQL) SQL ( Structured Query Language ) is used to create , manage and manipulate data in databases . It allows users to retrieve specific data using commands such as SELECT , FROM and WHERE , often combined with logical operators like AND and OR to filter results . The LIKE command and wildcards such as * and % are used to search for patterns within text data . SQL also supports data modification through commands like INSERT (to add data ), DELETE (to remove data ) and DROP (to delete entire tables ). More advanced queries can use nested SELECT statements or JOIN commands to combine data from multiple tables for more complex analysis . Referential Integrity Referential integrity ensures that relationships between tables in a relational database remain consistent . It means that a foreign key in one table must always refer to a valid primary key in another table . Referential integrity is important as it: Prevents orphan records (e.g. doctors linked to a non-existent patient). Keeps relationships between tables valid . Ensures queries and reports remain accurate . ACID Rules Transaction processing refers to the handling of a sequence of database operations (a transaction ) that must be completed fully or not at all . It ensures that databases remain accurate and consistent even if errors or system failures occur during the process . The ACID rules define the key properties of reliable transactions : Atomicity : The transaction is all or nothing - it either completes fully or not at all . Consistency : The database must remain valid before and after the transaction by following the same rules . Isolation : Transactions are independent , so one cannot interfere with another . Durability : Once completed , a transaction’s changes are permanent , even if the system crashes . Watch on YouTube : Database key terms Flat File & Relational databases Entity relationship (ER) diagrams Capturing & managing data Database normalisation SQL Referential integrity Transaction processing (ACID) Q uesto's K ey T erms Database Keys & Relationships: field, record, table, primary key, composite key, secondary key, indexing, foreign key, entity relationship (ER) diagram, one-to-one, one-to-many, many-to-many, flat file database, relational database Capturing & Managing Data: form, OCR, OMR, sensor, query by example, SQL, CSV, JSON, electronic and non-electronic data transfer SQL: SELECT, nested SELECT, FROM, WHERE, LIKE, AND, OR, DELETE, INSERT, DROP, JOIN, *, % Normalisation: first normal form (1NF), second normal form (2NF), third normal form ( 3NF), partial dependency, non-key dependency Referential Integrity & ACID: referential integrity, transaction processing, ACID (atomicity, consistency, isolation, durability), record locking, redundancy D id Y ou K now? In 2013 the web portal / search engine company Yahoo! was hacked , with all 3 billion user accounts in their database compromised - the largest hack in history . Personal details such as names , email addresses and hashed passwords were taken , causing major reputational and financial damage to the company . 3.1 - Compression & Encryption A-Level Topics 3.3 - Networks

Learn how to handle strings (text) in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 9a - String Handling What is String Handling? String handling refers to the manipulation of a string variable , typical uses include: Checking the length of a variable. Searching a variable for a certain phrase. Checking the number of times a specific character or word is used . String handling is used to examine passwords and to ensure that they are of an acceptable strength (e.g. by checking that they are at least 8 characters in length and include a mixture of capital letters , lowercase letters and symbols ). Password: arsenal Password: $tr0nG_pA$$w0rd Lowercase & Uppercase .lower() and .upper() are functions that convert a string into a fully lowercase or uppercase version. dogbreed = "Chihuahua" print (dogbreed.upper()) CHIHUAHUA character = "sPoNgeBoB" print (character.lower()) spongebob You may have realised that Python is very specific . 'yes ', 'Yes ' and 'YES ' are all treated as different values . Converting user input into one case , such as lowercase, and then comparing that input is a better way of checking an input than having an if statement with multiple or comparisons. The program below converts the user input into lowercase to compare. 'yes', 'Yes' and 'YES' are all converted to 'yes'. answer = input ( "Would you like water? " ) answer = answer.lower() if answer == "yes" : print ( "I'll fetch you a glass." ) else : print ( "Don't dehydrate!" ) Would you like water? yes I'll fetch you a glass. Would you like water? Yes I'll fetch you a glass. Would you like water? YES I'll fetch you a glass. Practice Task 1 Ask the user to enter their first name and surname. Print their surname in uppercase followed by their first name in lowercase. Example solution: Enter First Name: Jayden Enter Surname: Hargrove Welcome HARGROVE, jayden Count Characters The easiest way to count how many times a certain value appears within a string is to use the .count() command. It is important to note that, just like when using an input statement or calculation line, you must save the calculation into a variable . An example, for counting the number of e’s in a sentence, is below: sentence = input ( "Enter your sentence: " ) e_count = sentence.count( "e" ) print ( "There were" , e_count, "e's in your sentence!" ) Enter your sentence: even ellie eats elderberries There were 9 e's in your sentence! Practice Task 2 Create a program that counts how many instances of the letter a have been entered in a sentence. Bonus: Use the .lower() function in your code to include capital letters. Example solution: Enter a sentence: An angry aardvark named Aaron. That sentence had 8 a's. Finding the Length of a String Just like when we wanted to find the length of a list, we use the len command to see how many characters are in a string . It is sensible to save the result of the function into a variable so it can be used later . fruit = input ( "Enter a fruit: " ) length = len (fruit) print ( "That fruit was" , length, "characters." ) Enter a fruit: pineapple That fruit was 9 characters. A common reason for finding the length is as part of validation , for example, checking a password is more than 8 characters : password = input ( "Enter a new password: " ) length = len (password) if length >= 8: print ( "Password accepted!" ) else : print ( "Password is too short, must be at least 8 characters." ) Enter a password: snake54 Password is too short, must be at least 8 characters. Enter a password: pebblesthedog76 Password accepted! Practice Task 3 Create a program that asks for a name. Check that the name is between 4 and 10 characters. Print appropriate messages if it is within this range and if it isn't. Example solution: Enter a name: Tom That name is too short, it must be between 4 and 10 characters. Checking the Start / End of a String To determine if the first character in a string is a specific value use the .startswith() command. .startswith() is a function that will return True or False . Below is an example program to check if a name begins with the letter L . name = input ( "Enter a name: " ) if name.startswith( "L" ) == True : print ( "I like that name." ) else : print ( "I don't like that name." ) Enter a name: Lionel I like that name. Enter a name: Katjaa I don't like that name. Similarly, you can use .endswith() to check the last characters of a string . Practice Task 4 Ask the user to enter a country. Print a message if it ends with 'land', 'stan' or any other ending. Use .endswith() Example solution: Enter a country: Finland You have entered a 'land' country. There are 9 in the world. Enter a country: Kyrgyzstan You have entered a 'stan' country. There are 7 in the world. Enter a country: Peru Thanks for your entry. Note: You don't need to check if it's a valid country. Reversing a String To reverse a string, you write the variable name and then use square brackets to move one character at a time backwards. The first two colons are left empty as they denote where to start and end from (which don’t need to be changed). Therefore the -1 states that it will reverse from the end to the start : Ask the user to enter a random sentence. Print the sentence in reverse. Example solution: Practice Task 5 Printing Parts of a String You may want to print just part of a string or variable using square brackets. You can also use len to work out the length and work back, if you want to display the last characters: Practice Task 6 Ask the user to input a long word. Output the middle character of the word. Example solution: Split Strings Use the .split command to split a string into separate words . An empty split command such as words.split() will split at each space . You can enter a value in the brackets to split at certain characters , such as words.split(",") Use the len function to count the number of words once they have been split. You can use a for loop to cycle through each word. The program below checks the length of each word . Practice Task 7 Ask the user to input a sentence. Calculate and print the amount of words in the sentence. Calculate and print the amount of words that begin with s. Example solution: ⬅ Section 8 Practice Tasks 9b - Number Handling ➡

Learn how to delay processes using the sleep command in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 5b - Sleep Using Sleep To pause a program, import sleep from the time library . Type the word sleep followed by the number of seconds that you wish the program to break for in brackets . It must be a whole number . Below is an example of a program that imports the sleep command and waits for 2 seconds between printing: from time import sleep print ( "Hello!" ) sleep(2) print ( "Goodbye!" ) You can implement the sleep command within a for loop to produce an effective timer that outputs each second waited to the screen: You could also use a variable instead of a fixed value with the sleep command such as below: from time import sleep for second in range (1,11): print (second) sleep(1) from time import sleep seconds = int ( input ( "How many seconds should I sleep? " )) print ( "Going to sleep..." ) sleep(seconds) print ( "Waking up!" ) Sleep Task ( Slow Calculator) Create a slow calculator program that needs time to think in between calculations. Print a message to greet the user , then wait 3 seconds and ask them to enter a number . Wait another 3 seconds and ask them to enter a second number . Wait 2 more seconds , print “Thinking…” then 2 seconds later print the total of the two numbers added together . Example solution: ⬅ 5a - Rando m 5c - Date & Time ➡

Learn about protocols including FTP, HTTP, POP, SMTP, SNMP, TCP, UDP, ICMP, IP and the TCP/IP stack. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 3.2 - Protocols Watch on YouTube: Protocols TCP/IP Stack You need to know the role and uses of specific common protocols (FTP , HTTP , POP , SMTP , SNMP , TCP , UDP , ICMP , IP ). You also need to understand the structure , content and use of the 4-layer TCP/IP stack . What You Need to Know Common Protocols A protocol is a set of rules that determines how data is communicated between devices over a network . FTP FTP (File Transfer Protocol ) is used to transfer files between computers over a network , typically between a client and a server . It is used when uploading or downloading files from a server , such as transferring website files to a web server . HTTP HTTP (HyperText Transfer Protocol ) is used to request and transfer webpages and other web content between a web browser and a web server . It is used when accessing websites or when web-based applications communicate with servers . However, HTTPS is the secure , encrypted version commonly used today. POP POP (Post Office Protocol ) is used by an email client to retrieve emails from a mail server , traditionally storing them on the user's device . It is used when emails need to be downloaded from a mail server for access through an email application , particularly where local or offline access is required . SMTP SMTP (Simple Mail Transfer Protocol ) is used to send and transfer email messages between email clients and mail servers and between mail servers . It is required when a user sends an email , including transferring that email between mail servers on its way to the recipient . SNMP SNMP (Simple Network Management Protocol ) allows network administrators and management software to monitor and manage devices on a network to collect information about their status . It is used to monitor devices such as routers , switches , servers and printers , for example checking whether a network device is operating correctly . TCP TCP (Transmission Control Protocol ) provides reliable and ordered delivery of data packets between devices . It checks that packets arrive correctly and retransmits missing packets when necessary. It is used when accuracy and reliability are more important than speed , such as transferring files , loading webpages and sending emails . UDP UDP (User Datagram Protocol ) sends data quickly , although without checking that every piece has arrived or is in the correct order , reducing delays . It is used when speed is more important than perfect delivery , such as live video/audio , online gaming and voice calls . ICMP ICMP (Internet Control Message Protocol ) is used to send network status , diagnostic and error messages between network devices . It is required when diagnosing network problems and checking whether another device can be reached , such as when using the ping command. IP IP (Internet Protocol ) addresses and routes data packets across networks by using IP addresses to uniquely identify devices . It is used when data needs to be sent between devices across networks , with IP helping packets travel from the source towards the correct destination using an appropriate route . TCP/IP Stack The TCP/IP stack is a four-layer model that describes how data is prepared , transmitted across networks and received by applications . When sending data , it travels down through the layers . When receiving data , it travels up through the layers . Different protocols are used at specific layers of the model. Application Layer This is the top layer , where network applications and services interact with the network . It includes protocols such as HTTP , FTP , SMTP , POP and SNMP . It determines how applications communicate and exchange specific types of data across a network . Example : A web browser uses HTTP to request content from a web server . Transport Layer This layer is responsible for transporting data between devices and includes TCP and UDP . It determines how data should be delivered , including whether reliability (using TCP ) or speed (using UDP ) is more important . Example : TCP can ensure that a downloaded file arrives completely and in the correct order , while UDP can prioritise speed during an online game . Internet Layer This layer is responsible for addressing and routing packets between networks and includes protocols such as IP and ICMP . It ensures packets can travel towards the correct destination using IP addresses . Example : IP is used to route packets across the internet to the destination device . Network Access Layer This is the lowest layer , concerned with how data is physically transmitted across the network using technologies such as Ethernet (a wired connection) and WiFi . It handles communication between a device and the network it is directly connected to . Example : A laptop could transmit data wirelessly to a local router using WiFi . Q uesto's Q uestions 3.2 - Protocols: 1. What is a network protocol , and why do you think protocols are needed when devices communicate ? [ 2 ] 2. State the role of FTP , HTTP , POP , SMTP and SNMP and give an example of when each would be used. [2 each ] 3. State the role of TCP , UDP , ICMP and IP and give an example of when each would be used. [2 each ] 4. Describe the structure and purpose of each of the four layers of the TCP/IP stack . [2 each ] 5. Explain how different protocols and layers of the TCP/IP stack can work together to transfer data across a network , such as sending an email on a wired connection . [ 4 ] Online games use UDP because receiving data quickly is often more important than receiving every single packet . A tiny amount of missing data may be preferable to the game pausing while it waits for it to be resent . D id Y ou K now? 3.1 - APIs Topic List 4.1 - Security Considerations