Computer science
  • Exam boards
    • OCR past papers >
      • Paper1 (Sample)
    • Edexcel past papers >
      • 2020 Current spec (coming soon) >
        • Programming Language Subset (PLS)
      • Old 2016 SPEC >
        • Paper 1 (specimen1)
        • Paper 1 (specimen2)
        • Paper 1 (2018)
        • Paper 1 (2019)
        • Paper 2 (specimen1)
        • Paper 2 (2018)
        • Paper 2 (2019)
      • OLD 2013 SPEC >
        • Sample assessment 1 (old spec)
        • Sample assessment 2 (old spec)
        • June 2017 (old spec)
        • June 2016 (old spec)
        • June 2015 (old spec)
    • Paper 1 (by topic) >
      • Algorithms
      • Application software
      • Ascii
      • Binary
      • Cache
      • Client Server
      • Cloud
      • Compression
      • Computational thinking
      • CPU
      • Cyber security
      • Database
      • Fetch decode execute cycle
      • Embedded system
      • Encryption
      • File size
      • Flow chart
      • Hexadecimal
      • High Level language
      • ISP/Internet
      • Logic
      • Magnetic HDD
      • Networking
      • Open source
      • Operating system
      • Peer to peer
      • Images (Data representation)
      • Protocols
      • RAM
      • ROM
      • Run length encoding
      • Simulation software
      • Solid state HDD
      • Sound
      • Stored program concept
      • Utility software
    • Curriculum >
      • Binary
      • Hex
      • Data Representation
      • Compression
      • Encryption
      • What is a computer
      • How does a computer work
      • Hardware
      • Operating system
      • The CPU
      • Input devices
      • Data storage
      • Networks
      • Microcontrollers
      • Computational models
      • Emerging trends
      • Virtual machine
      • Models and simulators
      • Algorithms
    • Python >
      • Finding python
      • GCSE Python questions
      • Python coding >
        • Comments
        • Data types
        • Variables
        • If Else
        • If Elif Else
        • Functions
        • For loop
        • While loop >
          • While loop challenges
        • Data structures >
          • Looping thru 2D array
        • String slicing/indexing
        • Subprograms
        • Local/global variable
        • Validation and try
        • methods
        • File I/O
        • Pseudocode
        • Modules >
          • Turtle
        • Classes
        • NEA/Projects
  • KS3/Other
    • KS3 >
      • Online Safety >
        • Screen time
        • Online Safety questions
      • IT
      • Hardware >
        • All Hardware
        • Magnetic hard disk drive
        • Optical disk drive
        • Solid state drive
      • Software
      • Binary/Hex/Algorithms >
        • Binary
        • Binary explained
        • Hexadecimal - 1 digit
        • Hexadecimal - 2 digits
        • Algorithms
        • ASCII
        • Tests
      • Networks
      • Protocols/Cyber attacks
      • Logic >
        • CPU
        • AND gate
        • OR gate
        • NOT gate
        • Logical statements
      • Coding >
        • HTML
        • Scratch >
          • Scratch questions
        • Python >
          • Getting started
          • Functions
          • Variables
          • VariablesToo
          • inputs
          • Selection
          • Flowcharts
          • Data types
          • Pseudocode1
          • Pseudocode2
          • Subprogram1
          • Subprogram2
          • Coding challenges
    • BTEC CS
    • OCR GCSE CS >
      • Past paper JUNE 2015
      • Past paper June 2014
      • Past paper MAY 2012
      • Past paper JAN 2011
      • Past paper JUN 2011
    • AQA AS-Level CS >
      • AS Curriculum >
        • Multiple choice questions
    • Business studies >
      • Keywords
      • BS Revision - Multiple choice
      • Paper 1 (9-1)
      • Paper 2 (9-1)
  • Contact/More
    • Code editor
    • Contact us
    • Microbit ideas
    • More
  • Self test
    • 01 Random topics
    • 02 Programming
    • 03 Data
    • 04 Computers
    • 05 Networks
    • 06 Legal/Ethics/Enviro'
    • Coding/Programming

Python coding

PYTHON DICTIONARY


Comments

Data types

Variables

If Else

If Elif Else

Functions

For loop

While loop

Data structures

String slicing

User defined function

Local/Global variable

Validation and Try

Methods

​File I/O

Pseudocode

Modules​

What is an If Else statement?

If-Else allows your code to split in response to what the user chooses to do. For example,  you can use If-Else to code a simple yes or no question and based on the user choice, either the Yes code will be followed or the No code will be followed.



Picture

Python challenge - If statement

​Enter the following code in a Python code editor. Before running the code, what do you think it will do?. Press "F5" then "Enter" to run
Picture
Explanation:
The first line declares a variable called SkyColour that holds the value blue

The third line creates a condition based on SkyColour being blue. If it is true that the SkyColour is blue, then the line "The sky is blue today" will be displayed on the screen (line 4)

Line 6 will display "Good bye!" on the screen

If Statement explained

It is important to make the distinction in  Python between one equals sign and two equals sign:

= sets a value to a variable
== is a relational operator that means "is equal to". Other examples include:
Relational operator
Description
==
If the values of two operands are equal, then the condition becomes true.
!=
If values of two operands are not equal, then condition becomes true.
>
If the value of left operand is greater than the value of right operand, then condition becomes true.
<
If the value of left operand is less than the value of right operand, then condition becomes true.
>=
If the value of left operand is greater than or equal to the value of right operand, then condition becomes true.
<=
If the value of left operand is less than or equal to the value of right operand, then condition becomes true.
In this program, we have only coded for when a condition is met i.e. A message is displayed when the age is 18 or above, but we have not coded for if the condition is not met. We can do this by introducing the "Else" statement.


Python challenge - If-Else and the input function

Picture
In this example, a user is prompted to enter either a "y" or a "n". Based on the users choice, a condition is met, the code branches and one of the messages is displayed.

Python challenge - Greater than or equal to

Look at the code below. What will happen? What changes can you make to the code display the message "you are old enough to vote!"?
Picture

Python challenge - If-Else

In this example, we have coded for both a condition being met or not being met.​
Enter the following code in a Python code editor. Note that we have set the food as a kebab.  Press "F5" then "Enter" to run
Picture
What happens if you change the food to "chips" in both the variable called food and in the IF statement?

Home
Contact
Upload
Log in
  • Exam boards
    • OCR past papers >
      • Paper1 (Sample)
    • Edexcel past papers >
      • 2020 Current spec (coming soon) >
        • Programming Language Subset (PLS)
      • Old 2016 SPEC >
        • Paper 1 (specimen1)
        • Paper 1 (specimen2)
        • Paper 1 (2018)
        • Paper 1 (2019)
        • Paper 2 (specimen1)
        • Paper 2 (2018)
        • Paper 2 (2019)
      • OLD 2013 SPEC >
        • Sample assessment 1 (old spec)
        • Sample assessment 2 (old spec)
        • June 2017 (old spec)
        • June 2016 (old spec)
        • June 2015 (old spec)
    • Paper 1 (by topic) >
      • Algorithms
      • Application software
      • Ascii
      • Binary
      • Cache
      • Client Server
      • Cloud
      • Compression
      • Computational thinking
      • CPU
      • Cyber security
      • Database
      • Fetch decode execute cycle
      • Embedded system
      • Encryption
      • File size
      • Flow chart
      • Hexadecimal
      • High Level language
      • ISP/Internet
      • Logic
      • Magnetic HDD
      • Networking
      • Open source
      • Operating system
      • Peer to peer
      • Images (Data representation)
      • Protocols
      • RAM
      • ROM
      • Run length encoding
      • Simulation software
      • Solid state HDD
      • Sound
      • Stored program concept
      • Utility software
    • Curriculum >
      • Binary
      • Hex
      • Data Representation
      • Compression
      • Encryption
      • What is a computer
      • How does a computer work
      • Hardware
      • Operating system
      • The CPU
      • Input devices
      • Data storage
      • Networks
      • Microcontrollers
      • Computational models
      • Emerging trends
      • Virtual machine
      • Models and simulators
      • Algorithms
    • Python >
      • Finding python
      • GCSE Python questions
      • Python coding >
        • Comments
        • Data types
        • Variables
        • If Else
        • If Elif Else
        • Functions
        • For loop
        • While loop >
          • While loop challenges
        • Data structures >
          • Looping thru 2D array
        • String slicing/indexing
        • Subprograms
        • Local/global variable
        • Validation and try
        • methods
        • File I/O
        • Pseudocode
        • Modules >
          • Turtle
        • Classes
        • NEA/Projects
  • KS3/Other
    • KS3 >
      • Online Safety >
        • Screen time
        • Online Safety questions
      • IT
      • Hardware >
        • All Hardware
        • Magnetic hard disk drive
        • Optical disk drive
        • Solid state drive
      • Software
      • Binary/Hex/Algorithms >
        • Binary
        • Binary explained
        • Hexadecimal - 1 digit
        • Hexadecimal - 2 digits
        • Algorithms
        • ASCII
        • Tests
      • Networks
      • Protocols/Cyber attacks
      • Logic >
        • CPU
        • AND gate
        • OR gate
        • NOT gate
        • Logical statements
      • Coding >
        • HTML
        • Scratch >
          • Scratch questions
        • Python >
          • Getting started
          • Functions
          • Variables
          • VariablesToo
          • inputs
          • Selection
          • Flowcharts
          • Data types
          • Pseudocode1
          • Pseudocode2
          • Subprogram1
          • Subprogram2
          • Coding challenges
    • BTEC CS
    • OCR GCSE CS >
      • Past paper JUNE 2015
      • Past paper June 2014
      • Past paper MAY 2012
      • Past paper JAN 2011
      • Past paper JUN 2011
    • AQA AS-Level CS >
      • AS Curriculum >
        • Multiple choice questions
    • Business studies >
      • Keywords
      • BS Revision - Multiple choice
      • Paper 1 (9-1)
      • Paper 2 (9-1)
  • Contact/More
    • Code editor
    • Contact us
    • Microbit ideas
    • More
  • Self test
    • 01 Random topics
    • 02 Programming
    • 03 Data
    • 04 Computers
    • 05 Networks
    • 06 Legal/Ethics/Enviro'
    • Coding/Programming