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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 about the six parts of a data packet and how packet switching works. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.2: Data Packets & Switching Exam Board: Eduqas Specification: 2020 What is a data packet? When sending data across a network, files are broken down into smaller parts called data packets . Whole files are too large to transfer as one unit so data packets allow data to be transferred across a network quickly . Each packet of data is redirected by routers across networks until it arrives at its destination. Data packets may split up and use alternative routes to reach the destination address. When all the packets have arrived at the destination address the data is reassembled back into the original file. Contents of a Data Packet Data packets contain six distinct pieces of data which are used to redirect the packets towards the destination address. Packet Switching vs. Circuit Switching The key difference is that a circuit-switched network sends data along the same route . A packet-switched network sends data packets along different routes . Packet Switching With a packet-switched network the data is split into packets . The data packets are transmitted over a network and may take different routes to its destination. When all the packets have arrived the data is reassembled . The Internet is an example of a packet-switching network. Advantages of Packet Switching: Transmission is more secure as it is harder for a hacker to intercept complete data because it can take different routes . If a network device fails the data packets can take an alternative route . Data packets can be sent efficiently and individually across less busy routes . Disadvantages of Packet Switching: Reassembling the data takes longer because packets may arrive out of order . It is less reliable than circuit switching as some data packets may not reach the destination (this is called packet loss ). Circuit Switching When data is transmitted over a circuit-switched network all of the data takes the same route to the destination address in one continuous stream . The data is quickly reassembled at the destination because it is already in the correct order . The old telephone system is an example of a circuit-switched network. Advantages of Circuit Switching: Reassembling the data is quick because the packets arrive in the order that they were sent. It is more reliable than packet-switching because data is sent in one continuous stream . The transmission is fast and should encounter fewer errors - once the connection has been securely established . Disadvantages of Circuit Switching: Less secure as hackers could intercept the data and more easily access the data as it all takes the same route. Establishing a connection takes time to set up. If any device fails on the route then the whole connection breaks and data transfer will be incomplete. Q uesto's Q uestions 3.2 - Data Packets & Switching: 1. Draw the data packet diagram and label all 6 pieces of information . [ 6 ] 2a. Describe how packet switching works . [3 ] 2b. Describe the advantages of packet switching . [3 ] 2c. Describe the disadvantages of packet switching . [2 ] 3a. Describe how circuit switching works . [3 ] 3b. Describe the advantages of circuit switching . [3 ] 3c. Describe the disadvantages of circuit switching . [3 ] 3.1 - Network Characteristics Theory Topics 3.3 - Network Topology

Learn how to create and use two-dimensional lists in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 8b - 2D Lists Creating a List with Multiple Dimensions Lists can be given another dimension to hold data that is related to each other . A scenario: Three students have taken two Chemistry tests, and their teacher has recorded the results in a 2-dimensional array (note that Python does not use arrays but uses lists instead): To create this in Python: Printing a 2D List To print the whole list, use a for loop to cycle through each record. I have altered the normal i variable to be 'record', so it is more descriptive: Use the index number to print a specific record . Look at the table above and remember that Python starts counting at 0 so Edward is record 0, Bella 1 and Jacob 2: To print a specific data value, you need to define the record number and then the data index . When using 2D lists, the first value is the row, and the second value is the column . Use the table at the very top to help you visualise this: Practice Task 1 Use the introduction at the top to help you create a 2D list with three friends in the first column, their age in the second column and their favourite colour in the third column. Print the whole list. Then print just the second person's information. Example solution: Searching Through a 2D List To search through a multi-dimensional list then you need to search through each record and then each data element for a specific value: Practice Task 2 Use the 2D list that you created in the first practice task. Ask the user to enter a name. Search through the list and print the record of that person's name. Example solution: ⬅ 8a - Using Lists 8 c - Dictionaries ➡

Test your understanding of data types, calculations and modulo. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python - Section 3 Practice Tasks Task One: Square Number Create a program that asks the user to input a number and then prints the square of that number - to do this, multiply the number by itself . Remember: Break up variables and parts of a sentence in a print line by using commas. Example solutions: Enter a number: 12 The square of 12 is 144 Enter a number: 7 The square of 7 is 49 Task Two: Multiplying Numbers X Example solutions: Create a program that asks the user to input two numbers (num1 and num2 ). Multiply the two numbers together and print the total . Remember: Break up integer variables in a print line by using commas between each part of the sentence. Enter number one: 7 Enter number two: 9 7 x 9 = 63 Enter number one: 8 Enter number two: 12 8 x 12 = 96 Task Three: Turning 65 Example solutions: Create a program to input how old the user will turn this year and then print the year they will turn 65 . You could do this in just two lines but before trying that work out on paper the steps to calculating your own age you will turn 65. What steps did you take? Try to recreate those steps in Python. You might need to create another variable to make it easier. How old will you turn this year? 15 You will turn 65 in 2073 How old will you turn this year? 42 You will turn 65 in 2046 Task Four: Multiplication Table Let the user enter a number then print the first five multiplications in its times table. This can be done more simply when you learn about for loops but for now you will need to multiply the number by 1 , then multiply it by 2 etc. Try to make this program better by displaying the number and the value it is multiplied by in your print statements. Simple example solution: Enter a number: 8 8 16 24 32 40 Better example solution: Enter a number: 7 7 x 1 = 7 7 x 2 = 14 7 x 3 = 21 7 x 4 = 28 7 x 5 = 35 ⬅ 3b - Simple Calculations 4a - If Statements ➡

Test your ability to create a more complex program in Python based on a given scenario. Perfect for students learning GCSE Computer Science in UK schools. Extended Task 2 Lottery 17 8 4 13 20 Create a program to simulate a lottery draw. First, create an appropriate print line to welcome the user to your lottery draw. Then let the user enter five numbers between 1 and 20. Next, randomise five numbers between 1 and 20. Check to see how many numbers match and output an appropriate response for each scenario (e.g. “You have not matched any numbers, better luck next time!”) Once you have made the base program implement subroutines and lists . Make it as efficient as possible and professional-looking. Use pauses to reveal each number one at a time like a real lottery draw to build suspense. For this task, you will need to create a document and include the following sections (with screenshots where appropriate): An introduction to explain the Purpose of your program . A List of Requirements for a successful program. Screenshots of your code (with comments in your code to show understanding). Testing – Create a plan to show how you will test your program and then explanations of any errors that you found and how they were fixed . An Evaluation of what worked, what didn’t, and how you met each of your requirements from your original list. Also, discuss further improvements that you could have made to improve your program. Example solution: Helpful reminders for this task: Inputting Numbers Random Numbers Logical Operators Subroutines ⬅ Extended Task 1 (Pork Pies) Extended Task 3 (Blackjack) ➡

The homepage for the HTML section on CSNewbs. Learn how to create an HTML website from scratch and how each tag works. I'm Arthur the Alligator and I'm here to teach you HTML. HTML GUide Show me how to make a webpage in HTML from scratch. List of Tags Show me a list of tags I can use.

Learn about data formats such as ASCII, Unicode, CSV, fixed-width, JSON and XML and data types, including Boolean, character, date, integer, real and string. 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 2.1 - Data Formats & Types Watch on YouTube : Data Formats Data Types You need to know the characteristics , uses , advantages and disadvantages of six data formats (ASCII , Unicode , CSV , fixed-length , JSON and XML ). You also need to know the characteristics , uses , advantages and disadvantages of six data types (Boolean , character , date , integer , real and string ). What You Need to Know Data Formats ? YouTube video uploading soon Data Types ? YouTube video uploading soon Q uesto's Q uestions 2.1 - Data Formats & Types: 1. What? [2 ] 2. What? [1 ] 3. What? [1 ] 4. What? [1 ] ? D id Y ou K now? 1.3 - Storage Topic List 2.2 - Data Flow

Learn about the different protocols used on networks - HTTP, HTTPS, TCP, IP, Ethernet, WiFi, FTP and SMTP. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.5: Protocols Exam Board: Eduqas Specification: 2020 What is a protocol? A protocol is a set of rules that allow devices on a network to communicate with each other . TCP / IP is actually two separate protocols that combine together. TCP / IP (Transmission Control Protocol / Internet Protocol) TCP is a protocol that allows packets to be sent and received between computer systems. It breaks the data into packets and reassembles them back into the original data at the destination. IP is a protocol in charge of routing and addressing data packets . This ensures data packets are sent across networks to the correct destination . It is also an addressing system - every device on a network is given a unique IP address so data packets can be sent to the correct computer system. HTTP is used to transfer web pages over the Internet so that users can view them in a web browser . All URLs start with either HTTP or HTTPS (e.g. https://www.csnewbs.com). HTTPS is a more secure version of HTTP that works with another protocol called SSL ( Secure Sockets Layer ) to transfer encrypted data . You should see a padlock symbol in the URL bar if your connection to that website is secure. HTTP/HTTPS (Hypertext Transfer Protocol) Ethernet is a protocol for wired connections . Ethernet is used at both the data link and physical layers to describe how network devices can format data packets for transmission. WiFi is the main standard for wireless connections . WiFi is actually a brand name that uses a protocol called IEEE 802.11 . Another wireless standard is Bluetooth , for short-range data transfer. Connection Protocols Transfer Protocols FTP ( File Transfer Protocol ) is used to transfer files across a network. It is commonly used to upload or download files to/from a web server . SMTP ( Simple Mail Transfer Protocol ) is a protocol used to send emails to a mail server and between mail servers . Q uesto's Q uestions 3.5 - Protocols: 1. Describe each of the following protocols . It might be helpful to also draw an icon or small diagram for each one: a. TCP [ 2 ] b. IP [ 2 ] c. HTTP & HTTPS [ 3 ] d. WiFi (802.11) [ 1 ] e. Ethernet [ 2 ] f. FTP [ 2 ] g. SMTP [ 2 ] 2. State which protocol would be used in the following scenarios : a. Transferring a music file to a friend over the internet. [ 1 ] b. Sending an email to a family member in America. [ 1 ] c. Using a wireless connection to play a mobile game. [ 1 ] d. Using a webpage to enter a password securely. [ 1 ] e. Watching a video on YouTube. [1 ] 3.4 Network Hardware & Routing Theory Topics 3.6 - 7 Layer OSI Model

Learn how pseudocode and flowcharts are written as part of algorithms. This content is based on the 2016 Eduqas / WJEC GCSE Computer Science specification. Algorithms Pseudocode Pseudocode Pseudocode is not a specific programming language but a more general method of describing instructions . It should be unambiguous, and it should not resemble any particular kind of programming language (e.g. Python or Java), so it can theoretically be turned into real code in any language. Generally, pseudocode can be written in any way that is readable and clearly shows its purpose. However, the Eduqas exam board advises that pseudocode for the programming exam should follow the conventions below : Annotation { Write your comment in curly brackets} Define data type price is integer firstname is string Declare a variable's value set price = 100 set firstname = "Marcella" Input / output output "Please enter your first name" input firstname Selection (must have indentation) if firstname = "Steven" then output "Hello" + firstname elif firstname = "Steve" then output "Please use full name" else output "Who are you?" end if Iteration (while loop) while firstname ! = "Steven" output "Guess my name." input firstname repeat Iteration (for loop) for i in range 10 input item next i Define a subroutine Declare Sub1 [Subroutine content indented] End Sub1 Call a subroutine call Sub1 Flowcharts flowchart A flowchart can be used to visually represent an algorithm. The flowchart symbols are: Algorithm Example example Pseudocode {This is a program to see how many items you can buy in a supermarket before you spend over £100} total is integer, itemsentered is integer, itemprice is integer set total = 0 set itemsentered = 0 while total < 100 output "enter the price of the next item" input itemprice total = total + itemprice itemsentered = itemsentered + 1 repeat if itemsentered >= 20 then output "You are on your way to saving money." elif itemsentered => 30 then output "You're a real money saver." else output "Look for better deals next time." end if Stop Flowchart

Learn about legislation and regulations related to application development, including the Data Protection Act, Computer Misuse Act and Freedom of Information Act. 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 6.1 - Legal Considerations Watch on YouTube : Computer Misuse Act Data Protection Act UK General Data Protection Regulation Freedom of Information Act Privacy and Electronic Communications Regulations Independent bodies UK Information Commissioner's Office You need to know the latest version and main purpose of each act /regulation , as well as actions taken to comply with the act and the impacts of not complying with it. You must also understand how Privacy and Electronic Communications Regulations (PECR ) relate to the Data Protection Act and UK General Data Protection Regulation (UK GDPR ), and the role of the Information Commissioner's Office (ICO ) in the UK. What You Need to Know Computer Misuse Act ? YouTube video uploading soon Data Protection Act ? YouTube video uploading soon UK GDPR ? YouTube video uploading soon Freedom of Information Act ? YouTube video uploading soon PECR ? YouTube video uploading soon ICO & Independent Bodies ? YouTube video uploading soon Q uesto's Q uestions 6.1 - Legal Considerations: 1. What? [2 ] 2. What? [1 ] 3. What? [1 ] 4. What? [1 ] ? D id Y ou K now? 5.3 - Policies Topic List

A list of programming topics including HTML, Greenfoot, Python. All Programming Topics Python HTML Greenfoot Assembly Language App Inventor 2

Learn about networking standards and the seven layers of the Open Systems Interconnected (OSI) model - Application, Presentation, Session, Transport, Network, Data Link and Physical. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.6: 7-Layer OSI Model Exam Board: Eduqas Specification: 2020 What are networking standards? Networking standards are rules that allow computer systems to communicate across networks . Standards have been created to ensure devices can exchange data and work together . What is the 7-layer OSI Model? The OSI ( Open Systems Interconnection ) model is split into 7 layers . The model is used to visualise the different parts of a network as each of the seven layers has a specific role . Splitting a network design into layers is beneficial to programmers as it simplifies design , making it easier to modify and use . Each layer has a certain purpose and is associated with different protocols . The seven layers are explained below: 7 Allows humans and software applications to use the network e.g. browsers (HTTP /HTTPS ) and email (SMTP ) and file transfer (FTP ). 6 The purpose of the presentation layer is to display data in a standard format that other devices can accept and understand . 5 The session layer establishes a connection between computers allowing data to be sent between them. Data can be synchronised in each session to allow for efficient data transfer . 4 TCP breaks the data down into data packets . This layer makes sure the data is sent and received in the correct order and reassembled at the destination without errors. 3 IP is responsible for addressing and routing data packets . The optimal route for the data to take is calculated in this layer. Also known as the 'Internet Layer '. 2 Ethernet sets out the format of data packets . This layer handles transmission errors and passes data to the physical layer . 1 This layer converts the data packets into bits so they can be transferred across a physical connection using routers and switches . Q uesto's Q uestions 3.6 - 7-Layer OSI Model: 1a. What are networking standards ? [ 2 ] 1b. Describe why network designs are split into layers . [ 2 ] 2. Create a diagram similar to the one above and describe each layer of the OSI Model. [ 14 ] 3. Look at the statements below and name the layer that is being described: a. This layer ensures data packets are sent and received correctly. b. This layer checks for errors in transmission and sets out the data packet format. c. This layer displays data in a format that can be understood. d. This layer allows software like web browsers to interact with the network. e. This layer transfers bits across a connection using routers. f. This layer establishes a connection between computer systems. g. This layer uses addresses to ensure data packets take the correct route. [ 7 ] 3.5 - Protocols Theory Topics 3.7 - The Internet