Loops Python - Nick Reynolds September 31, 2017 Loops This - - PowerPoint PPT Presentation

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Sep 11, 2023 118 likes •275 views

Loops Python - Nick Reynolds September 31, 2017 Loops This Class Loop Types Assignment 1 Loops Whats next on the list? Whats a loop? I have a shopping list: Whats next on the list? Apple Banana

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Loops

Python - Nick Reynolds September 31, 2017

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This Class

Loops
Loop Types
Assignment 1

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Loops

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What’s a loop?

I have a shopping list:

Apple
Banana
Orange

I want to pick up each

ne in order.

Logically I loop through each until I’m done.

What’s next on the list? What’s next on the list? What’s next on the list? What’s next on the list? Nothing! Finished!

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For Loops

Most common loop in

Python >>> shopping = ['Apple', 'Orange', 'Banana'] >>> for item in shopping: ... print(item) Apple Orange Banana

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>>> shopping = ['Apple', 'Orange', 'Banana'] >>> for item in shopping: ... print(item) Apple Orange Banana

For Loops

Temporary loop variable

Most common loop in

Python

Item is a temporary variable

that will hold the value for each loop. e.g. Loop 1: Item = ‘Apple’ Loop 2: Item = ‘Orange’ Loop 3: Item = ‘Banana’

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>>> shopping = ['Apple', 'Orange', 'Banana'] >>> for item in shopping: ... print(item) Apple Orange Banana

For Loops

Temporary loop variable >>> for <variable> in <list>: ... # do stuff

Most common loop in

Python

Item is a temporary variable

that will hold the value for each loop. e.g. Loop 1: Item = ‘Apple’ Loop 2: Item = ‘Orange’ Loop 3: Item = ‘Banana’

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Pen and Paper

Checkpoint

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While Loops

Continues until the condition

is false

Used when the loop

condition is more complex Loop 1: Item = ‘Apple’ Loop 2: Item = ‘Orange’ Loop 3: Item = ‘Banana’ >>> shopping = ['Apple', 'Orange', 'Banana'] >>> n = 0 >>> while n < len(shopping): ... print(shopping[n]) ... n = n + 1 Apple Orange Banana

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>>> shopping = ['Apple', 'Orange', 'Banana'] >>> n = 0 >>> while n < len(shopping): ... print(shopping[n]) ... n = n + 1 Apple Orange Banana

While Loops

Condition

Item is a temporary variable

that will hold the value for each loop. e.g. Loop 1: Item = ‘Apple’ Loop 2: Item = ‘Orange’ Loop 3: Item = ‘Banana’ >>> while <condition>: ... # do stuff

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Pen and Paper

Checkpoint

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Practical

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Assignment 1

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References

http://pwp.stevecassidy.net/python/more-

python.html

https://thenounproject.com/