Python Coding & Programming The Complete ManualIssue 7的目錄

“It’s up to you how far to take your coding adventure!” MORE THAN CODE For those of you old enough to remember the ‘80s, the golden era of home computing, the world of computing was a very different scene to how it is today. 8-bit computers that you could purchase as a whole, as opposed to being in kit form and you having to solder the parts together, were the stuff of dreams; and getting your hands on one was sheer bliss contained within a large plastic box. However, it wasn’t so much the new technology that computers then offered, moreover it was the fact that for the first time ever, you could control what was being viewed on the ‘television’. Instead of simply playing one of the thousands of…

There’s a lot to like about Python, but don’t just take our word for it. Here are some amazing facts and figures surrounding one of the most popular programming languages of recent years. Alexa, Amazon’s Virtual Personal Assistant, uses Python to help with speech recognition. As of the end of 2024, Python was the most discussed language on the Internet. PYTHON AND LINUX SKILLS ARE THE THIRD MOST POPULAR I.T. SKILLS IN THE UK. Data analysis and Machine Learning are the two most used Python examples. Disney Pixar uses Python in its Renderman software to operate between other graphics packages. OVER 75% OF RECOMMENDED CONTENT FROM NETFLIX IS GENERATED FROM MACHINE LEARNING – CODED BY PYTHON. 90% OF ALL FACEBOOK POSTS ARE FILTERED THROUGH PYTHON-CODED MACHINE LEARNING. IT’S ESTIMATED THAT…

WHAT WE’RE USING Thankfully, Python is a multi-platform programming language available for Windows, macOS, Linux, Raspberry Pi and more. If you have one of those systems, then you can easily start using Python. COMPUTER Obviously you’re going to need a computer in order to learn how to program in Python and to test your code. You can use Windows (from XP onward) on either a 32 or 64-bit processor, an Apple Mac or Linux installed PC. AN IDE An IDE (Integrated Developer Environment) is used to enter and execute Python code. It enables you to inspect your program code and the values within the code, as well as offering advanced features. There are many different IDEs available, so find the one that works for you and gives the best results.…

EDITING CODE You will eventually reach a point where you have to move on from inputting single lines of code into the Shell. Instead, the IDLE Editor will allow you to save and execute your Python code. STEP 1 First, open the Python IDLE Shell and when it’s up, click on File > New File. This will open a new window with Untitled as its name. This is the Python IDLE Editor and within it you can enter the code needed to create your future programs. STEP 2 The IDLE Editor is, for all intents and purposes, a simple text editor with Python features, colour coding and so on; much in the same vein as Sublime. You enter code as you would within the Shell, so taking an example from…

FUNKY FUNCTIONS A function is a command that you enter into Python to do something. It’s a little piece of self-contained code that takes data, works on it and then returns the result. STEP 1 It’s not just data that a function works on. They can do all manner of useful things in Python, such as sort data, change items from one format to another and check the length or type of items. Basically, a function is a short word that’s followed by brackets. For example, len(), list() or type(). STEP 2 A function takes data, usually a variable, works on it depending on what the function is programmed to do and returns the end value. The data being worked on goes inside the brackets, so if you wanted to…

DEBUGGING Errors in code are called bugs and are perfectly normal. They can often be easily rectified with a little patience. The important thing is to keep looking, experimenting and testing. Eventually your code will be bug free. STEP 1 Code isn’t as fluid as the written word, no matter how good the programming language is. Python is certainly easier than most languages but even it is prone to some annoying bugs. The most common are typos by the user and whilst easy to find in simple dozen-line code, imagine having to debug multi-thousand line code. STEP 2 The most common of errors is the typo, as we’ve mentioned. The typos are often at the command level: mistyping the print command for example. However, they also occur when you have…

Data is everything; it can topple governments, change election results, and tell us the secrets of the universe. Over these coming pages we look at how you can create lists, tuples, dictionaries and multi-dimensional lists, and then how you can use them to forge exciting and useful programs. In addition, you will learn how you can use the date and time functions, write to files to your system and even create graphical user interfaces that will take your coding skills to new levels and into new project ideas.…

EXCEPTIONAL OBJECTS Rather than stop the flow of your code, Python includes exception objects which handle unexpected errors in the code. You can combat errors by creating conditions where exceptions may occur. STEP 1 You can create an exception error by simply trying to divide a number by zero. This will report back with the ZeroDivisionError: Division by zero message, as seen in the screenshot. The ZeroDivisionError part is the exception class, of which there are many. STEP 2 Most exceptions are raised automatically when Python comes across something that’s inherently wrong with the code. However, you can create your own exceptions that are designed to contain the potential error and react to it, as opposed to letting the code fail. STEP 3 You can use the functions raise exception…

The video game industry generates something in the region of $140 billion each year, and that number is growing fast. It’s a long way from the 8-bit days of the Commodore 64 and ZX Spectrum; the arcade titles that used to devour our pocket money and the wood panelled home consoles that Atari lovingly developed. These days, it’s all about teams of coders, graphic artists, musicians, PR, projects and development platforms. GAME CODE Coding a game from scratch, using raw code, has become something of the past. Most games these days are created using a range of development tools. These tools can be off-the-shelf engines, such as the Unreal Engine, while others are custom built around an original product, such as the world generating engine that Bethesda use for the…

FILEMAN.PY Copy the code below into a New > File and save it as FileMan.py. Once executed it will display the program title, along with the current time and date and the available options. Imports There are three modules to import here: Shutil, OS and Time. The first two deal with the operating system and file management and manipulation; and the Time module simply displays the current time and date. Note how we’ve included a try and except block to check if the user is running the code on a Linux system or Windows. Windows uses CLS to clear the screen, while Linux uses clear. The try block should work well enough but it’s a point of possible improvement depending on your own system.…

RNDPASSWORD.PY Copy the code and run it; each time you’ll get a random string of characters that can easily be used as a secure password which will be very difficult for a password cracker to hack. Secure Passwords There’s plenty you can do to modify this code and improve it further. For one, you can increase the number of characters the generated password displays and perhaps you can include special characters too, such as signs and symbols. Then, you can output the chosen password to a file, then securely compress it using the previous random number generator as a file password and send it to a user for their new password. An interesting aspect to this code is the ability to introduce a loop and print any number of random…

Linux is a remarkably versatile and powerful operating system. It’s used throughout the programming and engineering world, in science, space exploration, education, gaming and everything else in between. It’s the OS of choice for high-performance servers, it’s the backbone of the Internet and it powers the fastest supercomputers in the world. Knowing how to use Linux, and how it’s structured, is key to being able to create better Python content. The Raspberry Pi, for example, uses a Linux-based OS and, as such, makes for an excellent coding platform. Regardless of whether you’re using a Pi, like us, or a Linux Mint or Ubuntu, these pages will prove invaluable for your Python learning. Master Linux, master Python, and start engineering your coding future.…

LOOKING AT FILES Operating systems are built on files and folders, or directories if you prefer. While you’re used to viewing your own files, most operating systems keep other files out of sight. In Raspbian, you have access to every file in the system. STEP 1 We’ve already looked at “ls”, which lists the files in the working directory, but you are more likely to use a command like “ls–l”. The bit after the command (the ‘-lah’) is known as the argument. This is an option that modifies the behaviour of the command. STEP 2 The “-l” argument lists files and directories in long format. Each file and directory is now on a single line, and before each file is a lot of text. First you’ll see lots of letters…

USING THE MOVE COMMAND In Linux, renaming a file is simply moving it from one name to another and copying a file is moving it without deleting the original. Don’t panic, it’s quite easy to master. STEP 1 Before we can move anything around, we need to have a few test items in our home directory. Enter: touch testfile and mkdir testdir to create a test file and test directory in your home directory. Enter: ls to check that they are both present. STEP 2 Files and directories are moved using the mv command. This is different to the commands we’ve looked at so far because it has two arguments (remember Linux command line is command, option, argument). The first argument is the source (the file or directory to be…

THE JOY OF TEXT To be able to edit or create a text file, you need a good text editor. Linux has many but here are some in action on the Raspberry Pi. STEP 1 The first text editor for the Raspberry Pi is the default desktop environment app: Leafpad. To use, you can either double-click an existing text file or click the Raspberry Pi menu icon (in the top left of the desktop) and from the Accessories menu, choose Text Editor. STEP 2 From the Terminal there are even more options, although using the correct command, you can launch any of the desktop apps via the Terminal. One of the simplest, and a classic text editor that’s carried over from the Unix days, is vi. In the Terminal, enter:…

01000011 01101111 01100100 01101001 01101110 01100111 Essentially all forms of coding are made up of ones and zeros - on or off states. This works for both a modern computer and even the oldest known computational device. ~87 BC It’s difficult to pinpoint an exact start of when humans began to ‘program’ a device. However, it’s widely accepted that the Antikythera Mechanism is possibly the first ‘coded’ artefact. It’s dated to about 87 BC and is an ancient Greek analogue computer and orrery used to predict astronomical positions. ~850 AD The Banū Mūsā brothers, three Persian scholars who worked in the House of Wisdom in Baghdad, published the Book of Ingenious Devices in around 850 AD. Among the inventions listed was a mechanical musical instrument: a hydro-powered organ that played…

PYTHON POWER Ever since the earliest home computers were available, enthusiasts, users and professionals have toiled away until the wee hours, slaving over an overheating heap of circuitry to create something akin to magic. These pioneers of programming carved their way into a new frontier, forging small routines that enabled the letter ‘A’ to scroll across the screen. It may not sound terribly exciting to a generation that’s used to ultra high-definition graphics and open world, multi-player online gaming. However, forty-something years ago it was blindingly brilliant. Naturally these bedroom coders helped form the foundations for every piece of digital technology we use today. Some went on to become chief developers for top software companies, whereas others pushed the available hardware to its limits and founded the billion pound gaming…

Coding can be one of those experiences that sounds fantastic, but to get going with it, is often confusing. After all, there’s a plethora of languages to choose from, numerous apps that will enable you to code in a specific, or range, of languages and an equally huge amount of third-party software to consider. Then you access the Internet and discover that there are countless coding tutorials available, for the language in which you’ve decided you want to program, alongside even more examples of code. It’s all a little too much at times. The trick is to slow down and, to begin with, not look too deeply into coding. Like all good projects, you need a solid foundation on which to build your skill and to have all the necessary…

WHAT IS PROGRAMMING? It helps to understand what a programming language is before you try to learn one, and Python is no different. Let’s take a look at how Python came about and how it relates to other languages. PROGRAMMING RECIPES Programs are like recipes for computers. A recipe to bake a cake could go like this: Put 100 grams of self-raising flour in a bowl. Add 100 grams of butter to the bowl. Add 100 millilitres of milk. Bake for half an hour. CODE Just like a recipe, a program consists of instructions that you follow in order. A program that describes a cake might run like this: PROGRAM COMMANDS You might not understand some of the Python commands, like bowl.append and cake. cook (bowl). The first is a…

STARTING PYTHON Everything you need to begin programming with Python is available from the Raspberry Pi desktop. However, if you want, drop into the Terminal and update the system with: sudo apt-get update. STEP 1 With the Raspbian desktop loaded, click on the Menu button followed by Programming > Python 3 (IDLE). This opens the Python 3 Shell. Windows and Mac users can find the Python 3 IDLE Shell from within the Windows Start button menu and via Finder. STEP 2 The Shell is where you can enter code and see the responses and output of code you’ve programmed into Python. This is a kind of sandbox, where you’re able to try out some simple code and processes. STEP 3 For example, in the Shell enter: 2+2 After pressing Enter,…

COMMAND THE CODE Using the code we created in the previous tutorial, the one we named hello.py, let’s see how you can run code that was made in the GUI at the command line level. STEP 1 Python, in Linux, comes with two possible ways of executing code via the command line. One of the ways is with Python 2, whilst the other uses the Python 3 libraries and so on. First though, drop into the command line or Terminal on your operating system. STEP 2 Just as before, we’re using a Raspberry Pi: Windows users will need to click the Start button and search for CMD, then click the Command Line returned search; and macOS users can get access to their command line by clicking Go > Utilities >…

VARIOUS VARIABLES You’ll be working with the Python 3 IDLE Shell in this tutorial. If you haven’t already, open Python 3 or close down the previous IDLE Shell to clear up any old code. STEP 1 In some programming languages you’re required to use a dollar sign to denote a string, which is a variable made up of multiple characters, such as a name of a person. In Python this isn’t necessary. For example, in the Shell enter: name=”David Hayward” (or use your own name, unless you’re also called David Hayward). STEP 2 You can check the type of variable in use by issuing the type () command, placing the name of the variable inside the brackets. In our example, this would be: type (name). Add a new string variable:…

OPEN, READ AND WRITE In Python you create a file object, similar to creating a variable, only pass in the file using the open() function. Files are usually categorised as text or binary. STEP 1 Start by entering some text into your system’s text editor. The text editor is best, not a word processor, as word processors include background formatting and other elements. In our example, we have the poem The Cimmerian, by Robert E Howard. You need to save the file as poem.txt. STEP 2 You use the open() function to pass the file into a variable as an object. You can name the file object anything you like, but you will need to tell Python the name and location of the text file you’re opening: STEP 3 If…

A Python module is a Python-created source file that contains the necessary code for classes, functions and global variables. You can bind and reference modules to extend functionality, and create even more spectacular Python programs. Are you curious about how to improve your use of these modules to add a little something extra to your code? Then read on and learn how they can be used to fashion fantastic code with graphics, animations and operating system specific commands.…

E = MC2 The Math module provides access to a plethora of mathematical functions, from simply displaying the value of Pi, to helping you create complex 3D shapes. STEP 1 The Math module is built-in to Python 3; so there’s no need to PIP install it. As with the other modules present, you can import the module’s function by simply entering import math into the Shell, or as part of your code in the Editor. STEP 2 Importing the Math module will give you access to the module’s code. From there, you can call up any of the available functions within Math by using math, followed by the name of the function in question. For example, enter: This displays the sine of 2. STEP 3 As you will no doubt…

Despite how close AI and ML are, there are distinct differences between the two technologies. AI refers to the study of how to train a computer to accomplice the things that humans can do significantly better and faster. Whereas, ML is the ability for a computer to learn from its experiences, so that the outcome and performance will eventually become more accurate and accomplished. While different, they are both essentially discussing the same element: training a system to learn and do things independently. Where AI is said to lead to wisdom, ML reportedly leads to knowledge and, thanks to Python, that gap is getting closer every day. APPLICATIONS Both AI and ML are hugely present in today’s technology. Where, just a few years ago, most of us associated AI with…

NUMBERGUESS.PY Copy the code and see if you can beat the computer within five guesses. It’s an interesting bit of code that can be quite handy when your implementing a combination of the Random module alongside a while loop. Code Improvements Since this is such as simple script to apply to a situation, there’s plenty of room to mess around with it and make it more interesting. Perhaps you can include an option to take score, the best out of three rounds. Maybe an elaborate way to congratulate the player for getting a ‘hole in one’ correct guess on their first try. Moreover, the number guessing game code does offer some room for implementing into your code in a different manner. What we mean by this is, the code can…

MUSIC.PY The code utilises both the Time and Winsound modules, defining the tone and pitch and inserting small pauses of .5 of a second. Sweet Music Obviously the Winsound module is a Windows-only set of functions for Python. Open your IDLE in Windows and copy the code in. Press F5 to save and execute, then press the Enter key, as instructed in the code, to start the music. Naturally you can swap out the winsound. Beep frequency and durations to suit your own particular music; or you can leave it as is and enjoy. Perhaps play around with the various methods to make other music. For example, players of the Nintendo classic game, The Legend of Zelda: Ocarina of Time, can enjoy the game’s titular musical intro by entering:…

CREATING FILES Once you learn to recognise the files and directories that make up Raspbian OS, it’s time to discover how to make your own. Knowing how to make, edit and delete files and directories is essential if you want to make your own projects. STEP 1 We’re going to create a file using a command called Touch. Touch is an interesting command that reaches out to a file, or directory, and updates it (this changes the system time as if you’d just opened the file). You can see Touch in access using “ls–l” and checking the time next to a directory (such as Scratch). STEP 2 Now enter: touch Scratch and ls–l again and notice that the time has changed. It now matches the current time. You might be…

LOTS OF LINUX Linux is a huge and versatile command line language and there are hundreds of commands you can learn and use. Here are a few that can help you get more from your Raspberry Pi. STEP 1 The Raspberry Pi is a great little computer, so let’s start by getting some information. Enter: cat/proc/cpuinfo to view some details on your Raspberry Pi processors. If you have a Raspberry Pi 3 you will see four processors, along with the model name and other info. STEP 2 Remember that cat is used to list the contents of a text file, which is what cpuinfo is. There are other text files with system info available. Try “cat/proc/meminfo” to get information about your memory, “cat/proc/partitions” for information about your SD card, and…

Python is a high-level, general-purpose programming language that was developed by Guido van Rossum in the late eighties and is based upon a number of other languages, while being the successor to the popular ABC language. It has been devised to work on a human level, so it’s readable and understandable without needing to delve into obscure volumes of machine code, hexadecimal characters, or even ones and zeros. It’s clear, logical, comprehensive, powerful and functional, yet also easy to follow and learn. You will find Python at the heart of some of the most interesting and cutting-edge technologies in the world. It’s the code that binds supercomputer algorithms together; it’s used in the space industry, and in science and engineering. AI, and the likes of Alexa and Siri, Cortana and…

Python’s ability to create highly readable code within a small set of instructions has a considerable impact on our modern digital world. From the ideal, first programmers’ choice to its ability to create interactive stories and games; from scientific applications to artificial Intelligence and web-based applications, the only limit to Python is the imagination of the person coding in it. It’s Python’s malleable design that makes it an ideal language for many different situations and roles. Even certain aspects of the coding world, that require more efficient code, still use Python. For example, NASA utilises Python both as a stand-alone language and as a bridge between other programming languages. This way, NASA scientists and engineers are able to get to the data they need without having to cross multiple language…

THE POWER OF PI While having a far more powerful coding platform on which to write and test your code is ideal, it’s not often feasible. Most of us are unable to jump into a several hundred-pound investment when we’re starting off and this is where the Raspberry Pi can help out. While having a far more powerful coding platform on which to write and test your code is ideal, it’s not often feasible. Most of us are unable to jump into a several hundred-pound investment when we’re starting off and this is where the Raspberry Pi can help out. The Raspberry Pi is a fantastic piece of modern hardware that has created, or rather re-created, the fascination we once all had about computers, how they work, how to code…

Getting started with Python may seem a little daunting at first, but, thankfully, the language has been designed with simplicity in mind. Like most things, you need to start slow, master the basics, learn how to get a result, and how to get what you want from the code. This section covers numbers and expressions, user input, conditions and loops and the types of errors you will undoubtedly come across in your time with Python: the core foundations of good coding and Python code.…

INSTALLING PYTHON 3.X Microsoft Windows doesn’t come with Python preinstalled as standard, so it will be necessary to install it yourself manually. Thankfully, it’s an easy process to follow. STEP 1 Start by opening your web browser to www.python.org/downloads/. Look for the button detailing the Download link for Python 3.x. Python is regularly updated, changing the last digit for each bug fix and update. Therefore, don’t worry if you see Python 3.8, or more, as long as it’s Python 3, the code in this book will work fine. STEP 2 Click the Download button for version 3.x and save the file to your Downloads folder. When the file is downloaded, double-click the executable and the Python installation wizard will launch. From here, you have two choices: Install Now and Customise…

IT’S ALL MATHS, MAN You can get some really impressive results with the mathematical powers of Python; as with most, if not all, programming languages, maths is the driving force behind the code. STEP 1 Open up the GUI version of Python 3, as mentioned you can use either the Shell or the Editor. For the time being, you’re going to use the Shell just to warm our maths muscle, which we believe is a small gland located at the back of the brain (or not). STEP 2 In the Shell enter the following: You can see that Python can handle some quite large numbers. STEP 3 You can use all the usual mathematical operations: divide, multiply, brackets and so on. Practise with a few, for example: STEP 4 You’ve…

MASTERING MODULES Think of modules as an extension that’s imported into your Python code to enhance and extend its capabilities. There are countless modules available and as we’ve seen, you can even make your own. STEP 1 Although good, the built-in functions within Python are limited. The use of modules, however, allows us to make more sophisticated programs. As you are aware, modules are Python scripts that are imported, such as import math. STEP 2 Some modules, especially on the Raspberry Pi, are included by default, the Math module being a prime example. Sadly, other modules aren’t always available. A good example on non-Pi platforms is the Pygame module, which contains many functions to help create games. Try: import pygame. STEP 3 The result is an error in the IDLE…

Imaging a black hole is pretty difficult. The very nature of a black hole means that nothing can escape its immense gravitational field, even light itself. To quote the Wikipedia entry for a black hole: “A black hole is a region of spacetime exhibiting gravitational acceleration so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, no locally detectable features appear to be observed. In many ways, a black hole acts like…

LIGHTS, CAMERA, ACTION The Tkinter module is an ideal starting point for learning animation within Python. Naturally, there are better custom modules out there, but Tkinter does the job well enough to get a grasp on what’s needed. STEP 1 Let’s make a bouncing ball animation. First, we will need to create a canvas (window) and the ball to animate: STEP 2 Save and Run the code. You will see a blank window appear, with a red ball sitting in the upper left corner of the window. While this is great, it’s not very animated. Let’s add the following code: STEP 3 Insert the new code between the ball1 = canvas.create_oval(5,5,60,60, fill=’red’) line and the gui.mainloop() line. Save it and Run. You will now see the ball move from the…

We’ve included a vast Python code repository for you to freely use in your own programs. There’s plenty in here to help you create a superb piece of programming, or extend your project ideas. We’ve got code for making backups of your files and folders, number guessing games, random number generators, Google search code, game code, animation code, graphics code, text adventure code and even code that plays music stored on your computer. We’ve broken down some of the newer, and extended, concepts of the code to help you better understand what’s going on. This way you can easily adapt it to your own uses. This is an excellent resource that you won’t find in any other Python book. So use it, take it apart, adapt it to your own…

RNDNUMGEN.PY It might be simple but this little piece of code will ask the user for two sets of numbers, a start and a finish. The code will then pluck out a random number between the two sets and display it. More Input While an easy code to follow, it could be more interesting if you prompt the user for more input. Perhaps you can provide them with addition, subtraction, multiplication elements with their numbers. If you’re feeling clever, see if you can pass the code through a Tkinter window or even the Ticker window that’s available on Page 98. Furthermore, the core of the code can be used in a text adventure game, where the character fights something and their health, along with the enemy’s, is reduced by a…

EPICSCROLL.PY We’ve used the poem Cimmeria by Robert E. Howard for the code’s scrolling text, along with a dramatic black background and red text. We think you’ll agree, it’s quite epic. A Long Time Ago… The obvious main point of enhancement is the actual text itself. Replace it with a list of credits, or an equally epic opening storyline to your Python game, and it will certainly hit the mark with whoever plays it. Don’t forget to change the screen resolution if needed; we’re currently running it at 800 x 600.…

ADVENTURE.PY The Adventure game uses just the Time module to begin with, creating pauses between print functions. There’s a help system in place to expand upon, as well as the story itself. Adventure Time This, as you can see, is just the beginning of the adventure and takes up a fair few lines of code. When you expand it, and weave the story along, you’ll find that you can repeat certain instances such as a chance meeting with an enemy or the like. We’ve created each of the two encounters as a defined set of functions, along with a list of possible choices under the cmdlist list, and cmd variable, of which is also a defined function. Expanding on this is quite easy, just map out each encounter and choice…

HANGMAN.PY We’ve made a Hangman game board (the gallows) out of characters that can be displayed in the IDLE Shell, along with a huge bank of words to randomly choose from. QUIT() Since this is the last example in our Python code repository, we thought we’d go out with a bang and feature the hangman gallows being drawn with each incorrect guess of the word. Don’t worry if it looks misaligned in the text here, this is merely due to the differences between using the Python IDLE editor and pasting the code into a word processor (which formats things differently). There’s plenty you can do to improve, enhance and expand on what we’ve presented here. You can include a routine that returns an error if the user enters a number…

GETTING AROUND To drop into the Terminal, click on the fourth icon from the left along the top of the Raspberry Pi desktop, the one with a right-facing arrow and an underscore. This is the shell, or Terminal. STEP 1 First, you’re going to look at directories and the directory path. A directory is the same thing as a folder, however in Linux it’s always called a directory. These are placed inside each other using a “/” character. So when you see/home/pi it means the pi directory is inside the home directory. Enter: clear and press return to clean the screen. Now enter: pwd. This stands for Print Working Directory and displays/home/pi. STEP 2 When you log in to your Raspberry Pi, you don’t start at the base of the…

MANAGING FILES AND DIRECTORIES Now that you know how to create files, you’ll want to learn how to make directories, which are the same thing as folders, as well as move items around. If you are more used to working with a desktop interface, this can take a bit of getting used to. STEP 1 Enter: ls to quickly view all the directories currently in in the home location. Directories are created using the “mkdir” command (make directory). Enter: mkdir testdir to create a new directory in your home directory. Enter: ls again to see it. STEP 2 The “mkdir” command is different to touch, in that it doesn’t update the timestamp if you use it with a directory that already exists. Enter: mkdir testdir again and you’ll get the…

A adduser arch Add a new user Print machine architecture awk Find and replace text within file(s) B bc An arbitrary precision calculator language C cat Concatenate files and print on the standard output chdir Change working directory chgrp Change the group ownership of files chroot Change root directory cksum Print CRC checksum and byte counts cmp Compare two files comm Compare two sorted files line by line cp Copy one or more files to another location crontab Schedule a command to run at a later time csplit Split a file into context-determined pieces cut Divide a file into several parts D date Display or change the date & time dc Desk calculator dd Data Dump, convert and copy a file diff Display the differences between two files dirname Convert…