Lists Flashcards
List are:
- Ordered sequences that can hold a variety of object types.
- [] Brackets and commas to separate objects in list [1,2,3,4,5]
- List support indexing and slicing
- List can be nested and also have a variety of useful methods.
List examples:
my_list = [1,2,3,4]
my_list2 = [‘STRING’,100,23.3]
Cancatinate 2 list
mylist = [‘one’,’two’,’three’]
another_list = [‘apple’,’pie’,’cherry’]
mylist + another_list
Combine two list
mylist = [‘one’,’two’,’three’]
another_list = [‘apple’,’pie’,’cherry’]
mynewlist = mylist + another_list
Change the first string in this list to “One for all’
new_list = [‘one’, ‘two’, ‘three’, ‘four’, ‘five’]
new_list[0] = ‘One for all’
would change it to
new_list = [‘One for all’, ‘two’, ‘three’, ‘four’, ‘five’]
Add an element to the end of a list:
new_list.
new_list.append(‘six’)
new_list = [‘One for all’, ‘two’, ‘three’, ‘four’, ‘five’, ‘six’]
NOTE:This affects the list in place
Remove the last element from a list:
Done using pop
new_list.pop()
new_list = [‘One for all’, ‘two’, ‘three’, ‘four’, ‘five’, ‘six’]
Remove an element from the 3 position
new_list = [‘One for all’, ‘two’, ‘three’, ‘four’, ‘five’, ‘six’]
new_list.pop(3)
new_list = [‘One for all’, ‘two’, ‘three’, ‘five’, ‘six’]
Sort list
new_list = [‘a’, ‘e’, ‘x’, ‘b’, ‘c’]
num_list = [4,1,8,3]
Call the sort method
new_list.sort()
NOTE:This sorts the list in place
Reassign this list but first Sort list
new_list = [‘a’, ‘e’, ‘x’, ‘b’, ‘c’]
num_list = [4,1,8,3]
new_list.sort()
my_sorted_list = new_list
Reverse this list
new_list = [‘a’, ‘e’, ‘x’, ‘b’, ‘c’]
num_list = [4,1,8,3]
- Call the reverse method
- num_list.reverse()
[3,8,1,4]
- new_list.reverse()
[‘c’, ‘b’, ‘e’, ‘a’]
How do I index a nested list? For example if I want to grab 2 from [1,1,[1,2]]?
You would just add another set of brackets for indexing the nested list, for example:
my_list[2][1]
NOTE: List follow the same numbering sequence as strings.
If lst=[0,1,2] what is the result of lst.pop()
2
Lists can have multiple object types.
True
If lst=[‘a’,’b’,’c’] What is the result of lst[1:]?
[‘b’,’c’]
