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 a For Loop?

A For Loop steps through a sequence one character (or element) at a time. For this to work, a variable is used to store each element. When the loop is running, inside the "loop body" (which is the next line which is indented), the loop can do whatever you want with each successive element. See example below:
Picture
In this example, the variable called "SingleLetter" is holding each element of the string "Paris". First it holds the "P" then the "a" and so on. In the loop body, I am coding each letter to be displayed on screen one at a time. Try the code out in a code editor to see the result.

Picture

A for loop using an imput

In this example, a name is being asked to be inputted and is used in the body of the loop. How many times will the name be displayed? Run the code then change the 3 to a 2 and run it again.

Python challenge - For loop with range() function

​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
In this example, the variable called "counting" is holding each element of "range(10)". Range(10) are the numbers 0 to 9. First it holds the first element "1" then then "2" and so on. In the loop body, each number is to be displayed on screen one at a time. Try the code out in a code editor to see the result.
range (Start, Stop)
range (Start, Stop, Step)

Python challenge - For loop with list data structure

​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
In this example, a list called animals is declared and it holds five animals. The variable called "nextAnimal" is holding each element of the list called "animals". First the variable holds the first element "cat" then then "dog" and so on. In the loop body, the sentence "the animal is a" and then each animal is to be displayed on screen one at a time. Try the code out in a code editor to see the result.

​Python challenge - For loop with list data structure and string slicing

​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
In this example a list is declared that contains six animals. The code then enters a loop with a condition that specifies that the first letter in each animal must be a letter "c". If this condition is met, then only the animals that begin with a "c" will be displayed on screen. Try the code out in a code editor to see the result.

​Python challenge - For loop with list data structure and variables

​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
In this example, a list is declared with some prices in it. A loop then declared and in the loop body each item has a 50% discount applied to it and then the discount is subtracted from the item and stored in a variable called newPrice. This new price is then displayed on the screen. Try the code out in a code editor to see the result.

Index in range

Ever had an "index out of range" error? It means you are attempting to access an element in a list e.g. accessing a 6th element in a list with 5 elements.
Click here - For Loop challenges
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