• In Python, Strings and Lists are very similar types.
  • The slicing syntax for Strings is also applicable to Lists. 
    myList = [1,2,3,4,5]
myList[3:]
  • Outputs: [4, 5]
  • Can also pass in a third value as well. 
    # The 2 --> is a Step Size of 2
myList[0:6:2]
  • Will output [1, 3, 5].
  • The equivalent to that is: ``` myList[::2]

myList[0:6:3]

* Will output: `[1, 4]`
* We can also use the `range` function.
	* Its a sequence type.
	* Its like a Tuple - has an order, is immutable and isn't frequently used except for looping through code.
	* For example:

for i in range(100): print(i)

* This will output the following:

0 1 2 3 4 5 and so on to 100

* Can take this same range and convert it to a list.

myList = list(range(100))

If we take that and go through every other number:

myList[::2]

* The output is:

[0 2, 4, 6, up to 100 ]

* Can do multiple step sizes.
* If you enter a negative number, you step through the list backwards.

myList[::-1] [99, 98, 97, 96, etc ]

* Modifying Lists.

myList = [1,2,3,4] myList.append(5) print(myList)

* Will output:

[1, 2, 3, 4, 5]

* `append` adds an item to the list.
* If you want to insert an item in any position, can use `insert`.

The index is 3

myList.insert(3, ‘a new value’)

* Will output:

[1, 2, 3, ‘a new value’, 4, 5]

* To remove something from a list, we do:

myList.remove(‘a new value’) myList

* The output is then:

[1, 2, 3, 4, 5]

* If the item you want isn't in the list, it will throw an error.
* The second way to remove an item from a list is with `pop`.

myList.pop()

* Takes one item off the end of the list.
* Run `myList` again and we get:

[1, 2, 3, 4]

* Can also run this:

The while statement evaluate to False, when the length of myList = 0

while len(myList): print(myList.pop())

* If you then run `myList`, you will see that all of the values have been removed.

a = [1,2,3,4,5] b = a a.append(6) print(b)

* This will then print out the following:

[1, 2, 3, 4, 5, 6]

* We can use the `copy` function to make an identical copy of the list and store that separately in memory.

a = [1,2,3,4,5] b = a.copy() a.append(6) print(a) print(b)

* That will output:

[1, 2, 3, 4, 5, 6] [1, 2, 3, 4, 5] ```

  • Lists are one of the most fundamental and useful data structures in Python.

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