Teach yourself Programming with pseudocode and Python for AQA GCSE Computer Science (8520) Students Workbook By Nichola Lacey Contents Introduction ............................................................................................................................................ 5 How to use this book .......................................................................................................................... 5 Who should use this book? ................................................................................................................. 5 Installing Python ................................................................................................................................. 5 Data types ............................................................................................................................................... 6 Using data types .................................................................................................................................. 7 Integer ............................................................................................................................................. 7 Real.................................................................................................................................................. 7 Boolean ........................................................................................................................................... 8 Character ......................................................................................................................................... 8 String ............................................................................................................................................... 8 End of chapter recap ......................................................................................................................... 11 Programming Concepts ......................................................................................................................... 12 Variables ........................................................................................................................................... 12 Constants .......................................................................................................................................... 13 Defining variables and constants ...................................................................................................... 14 Rules of naming variables and constants ...................................................................................... 14 Assignment........................................................................................................................................ 15 Iteration ............................................................................................................................................ 17 Condition-controlled iteration ...................................................................................................... 17 Count-controlled iteration ............................................................................................................ 19 Indenting lines of code .................................................................................................................. 19 Selection ............................................................................................................................................ 21 Nested selection and nested iteration .............................................................................................. 23 Nested iteration ............................................................................................................................ 24 Nested selection ........................................................................................................................... 25 Subroutines (procedures and functions) .......................................................................................... 30 Teach yourself programming with pseudocode and Python for AQA GCSE Computer Science by Nichola Lacey Page 1 Advantages of using subroutines in programs.............................................................................. 31 Passing data within programs ....................................................................................................... 32 Returning single vales ................................................................................................................... 32 Returning multiple values ............................................................................................................. 33 Global and local variables ............................................................................................................. 34 Why use local variables? ............................................................................................................... 34 Functions and Procedures............................................................................................................. 35 End of chapter recap ......................................................................................................................... 40 Operators .............................................................................................................................................. 41 Arithmetic operations in a programming language .......................................................................... 41 Relational operators in a programming language ............................................................................ 43 Boolean operations in a programming language .............................................................................. 45 Using operators in iteration and selection structures ...................................................................... 46 End of chapter recap ......................................................................................................................... 48 Data Structures ..................................................................................................................................... 49 Arrays ................................................................................................................................................ 49 One-dimensional arrays ................................................................................................................ 49 Creating and using a 1D array ....................................................................................................... 50 Two-dimensional arrays ................................................................................................................ 53 Creating and using a 2D array ....................................................................................................... 54 Complex data types .......................................................................................................................... 56 End of chapter recap ......................................................................................................................... 58 Input/Output and file handling ............................................................................................................. 59 User input from the keyboard .......................................................................................................... 59 Displaying output .............................................................................................................................. 59 Reading from and writing to a text file ................................................................................................. 60 File location ................................................................................................................................... 60 Writing to a text file ...................................................................................................................... 60 Teach yourself programming with pseudocode and Python for AQA GCSE Computer Science by Nichola Lacey Page 2 Reading from a text file ................................................................................................................. 63 End of chapter review ....................................................................................................................... 64 String handling operations .................................................................................................................... 65 Length ............................................................................................................................................... 65 Position ............................................................................................................................................. 65 Substring ........................................................................................................................................... 66 Concatenation ................................................................................................................................... 67 Character codes ................................................................................................................................ 67 String conversions ............................................................................................................................. 68 Converting string