Introduction to computing
Importance of computing:
- Forecasting natural disasters
- Computer Aided Tomography scans
- Finding and distributing information (internet)
- Entertainment (games, instant messaging)
- E-commerce (online shopping)
What is Computer Science?
The study of
- Computer software
- Algorithms, abstraction & efficiency
- Theoretical foundations for computation
Problem solving
1. Understand the problem
2. Plan – how to solve the problem
3. Carry out the plan – write the program
4. Assess result
5. Describe what you have learnt
6. Document the solution
Algorithms
Algorithm: set of steps to accomplish a task
Must be precise so that they:
- Are repeatable
- Have a predictable outcome
- Can be executed by different people
Elements of an algorithm:
- Sequence – each step is followed by another step
- Selection – a choice may be made among other alternatives
- Iteration – a set of steps may be repeatecd
Programming process
- Input – get information from the real world
, - Process – process the data internally
- Output – send the computed data back to the real world
Python Basics
Definitions
Program: set of instructions given to a computer, corresponding to an algorithm to
solve a problem
Programming: the act of writing a program
Integrated Development Environment (IDE): graphical interface with menus and
windows
Literals: actual data values written into a program
Function: block of code
Syntax
- Every statement starts on a new line (generally)
- Statements are case sensitive (ie: STUFF vs stuff)
Comments
- Everything after a # is a comment (ie: for humans)
- Brief description: author & date at top of program
- Purpose of each function (if more than one function)
- Short explanation of non-obvious part of code
Syntax Errors
Syntax error when the program does not conform to the structure required
Program will not run if there is a syntax error
Examples of syntax errors:
- print spelt incorrectly
Logic errors
Logic errors when the program runs but does not work as expected
You must test your program to make sure there are no logic errors
Importance of computing:
- Forecasting natural disasters
- Computer Aided Tomography scans
- Finding and distributing information (internet)
- Entertainment (games, instant messaging)
- E-commerce (online shopping)
What is Computer Science?
The study of
- Computer software
- Algorithms, abstraction & efficiency
- Theoretical foundations for computation
Problem solving
1. Understand the problem
2. Plan – how to solve the problem
3. Carry out the plan – write the program
4. Assess result
5. Describe what you have learnt
6. Document the solution
Algorithms
Algorithm: set of steps to accomplish a task
Must be precise so that they:
- Are repeatable
- Have a predictable outcome
- Can be executed by different people
Elements of an algorithm:
- Sequence – each step is followed by another step
- Selection – a choice may be made among other alternatives
- Iteration – a set of steps may be repeatecd
Programming process
- Input – get information from the real world
, - Process – process the data internally
- Output – send the computed data back to the real world
Python Basics
Definitions
Program: set of instructions given to a computer, corresponding to an algorithm to
solve a problem
Programming: the act of writing a program
Integrated Development Environment (IDE): graphical interface with menus and
windows
Literals: actual data values written into a program
Function: block of code
Syntax
- Every statement starts on a new line (generally)
- Statements are case sensitive (ie: STUFF vs stuff)
Comments
- Everything after a # is a comment (ie: for humans)
- Brief description: author & date at top of program
- Purpose of each function (if more than one function)
- Short explanation of non-obvious part of code
Syntax Errors
Syntax error when the program does not conform to the structure required
Program will not run if there is a syntax error
Examples of syntax errors:
- print spelt incorrectly
Logic errors
Logic errors when the program runs but does not work as expected
You must test your program to make sure there are no logic errors
