@@ -100,7 +100,8 @@ Lists have a few [useful
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methods] ( https://docs.python.org/3/tutorial/datastructures.html#more-on-lists ) .
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Some of the most commonly used ones are append, extend and remove.
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` append ` adds an item to the end of a list, ` extend ` adds
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- multiple items from another list and ` remove ` removes an item.
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+ multiple items from another list and ` remove ` removes an item.
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+ It can also be added with the method of ` insert `
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``` python
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>> > names
@@ -115,7 +116,9 @@ multiple items from another list and `remove` removes an item.
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>> > names.extend([' go|dfish' , ' theelous3' ]) # wb guys
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>> > names
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[' wub_wub' , ' RubyPinch' , ' Nitori' , ' Akuli' , ' go|dfish' , ' theelous3' ]
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- >> >
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+ >> > names.insert(len (names), " Aly" )
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+ >> > names
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+ [' wub_wub' , ' RubyPinch' , ' Nitori' , ' Akuli' , ' go|dfish' , ' theelous3' , ' Aly' ]
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```
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Note that ` remove ` removes only the first match it finds.
@@ -128,6 +131,26 @@ Note that `remove` removes only the first match it finds.
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>> >
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```
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+ The method ` pop ` also works for delete elements of the list.
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+
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+ ``` python
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+ >> > names = [' theelous3' , ' go|dfish' , ' theelous3' ]
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+ >> > names.pop(1 )
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+ >> > names # the second item was removed
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+ ' go|dfish'
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+ >> > names
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+ [' theelous3' , ' theelous3' ]
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+
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+ >> > names = [' theelous3' , ' go|dfish' , ' theelous3' ]
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+ >> > names.pop()
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+ theelous3'
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+ >> > names
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+ [' theelous3' , ' go|dfish' ]
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+
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+ >> >
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+ ```
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+
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+
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If we need to remove all matching items we can use a simple while loop.
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We'll talk more about loops [ in the next chapter] ( loops.md ) .
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@@ -230,6 +253,44 @@ like this:
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![ Different lists.] ( ../images/differentlist.png )
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+
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+ We can count the number of items that have a list.
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+
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+ ``` python
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+ >> > a = [1 , 2 , 3 , 4 , 2 , 5 , 2 ]
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+ >> > a.count(2 )
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+ 3
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+ >> > a.count(5 )
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+ 1
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+ >> > a.count(9 )
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+ 0
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+ >> > a = [' theelous3' , ' wub_wub' , ' RubyPinch' , ' go|dfish' , ' Nitori' ]
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+ >> > a.count(' wub_wub' )
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+ 1
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+ ```
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+
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+
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+ We can sort the items that have a list
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+
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+ ``` python
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+ >> > a = [1 , 2 , 3 , 4 , 2 , 5 , 2 ]
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+ >> > a.sort()
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+ >> > a
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+ [1 , 2 , 2 , 2 , 3 , 4 , 5 ]
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+ >> > a.sort(reverse = True )
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+ >> > a
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+ [5 , 4 , 3 , 2 , 2 , 2 , 1 ]
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+ >> > a = [' wub_wub' , ' theelous3' , ' RubyPinch' , ' go|dfish' , ' Nitori' ]
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+ >> > a.sort()
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+ >> > a
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+ [' Nitori' , ' RubyPinch' , ' go|dfish' , ' theelous3' , ' wub_wub' ]
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+ >> > a.sort(reverse = True )
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+ [' wub_wub' , ' theelous3' , ' go|dfish' , ' RubyPinch' , ' Nitori' ]
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+ >> >
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+ ```
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+
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+
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+
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## Tuples
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Tuples are a lot like lists, but they're immutable so they
@@ -274,6 +335,41 @@ but some people like to do it this way.
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>> >
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```
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+
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+ You can have nested tuples.
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+
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+ ``` python
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+ >> > n = 1 , 2 , 3
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+ >> > n
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+ (1 , 2 , 3 )
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+ >> > n[0 ]
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+ 1
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+ >> > l = ' a' , ' b' , ' c'
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+ >> > l
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+ (' a' , ' b' , ' c' )
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+ >> > l[0 ]
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+ ' a'
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+ >> > t = n, l
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+ >> > t
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+ ((1 , 2 , 3 ), (' a' , ' b' , ' c' )) # The tuples n and l are nested
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+ >> > t[0 ]
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+ (1 , 2 , 3 )
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+ >> > t[1 ]
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+ (' a' , ' b' , ' c' )
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+ >> > t[1 ][2 ]
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+ ' c'
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+ >> > v = ([1 , 2 , 3 ], [3 , 2 , 1 ,[7 , 8 , 9 ]])
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+ >> > v
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+ ([1 , 2 , 3 ], [3 , 2 , 1 , [7 , 8 , 9 ]])
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+ >> > v[1 ]
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+ [3 , 2 , 1 , [7 , 8 , 9 ]]
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+ >> > v[1 ][3 ]
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+ [7 , 8 , 9 ]
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+ >> > v[1 ][3 ][0 ]
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+ 7
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+ ```
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+
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+
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Tuples don't have methods like append, extend and remove
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because they can't change themselves in-place.
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