x = [23, 9, 7, 9]
x[23, 9, 7, 9]4 Lists
type(x)list4.1 append(): add item to end of list
x.append(12)
x[23, 9, 7, 9, 12]4.2 extend(): Append elements of another iterable
z = [19, 21]
x.extend(z)
x[23, 9, 7, 9, 12, 19, 21]4.3 pop(): Remove and return element of list by index
Defaults to the last element
x[23, 9, 7, 9, 12, 19, 21]x.pop()21x[23, 9, 7, 9, 12, 19]Remove and return the 5th element:
x.pop(4)124.4 insert(): Insert element before index
Note the function requires two inputs, there is no default location to insert
x.insert(4, 13)x[23, 9, 7, 9, 13, 19]4.5 remove(): remove first occurence of value
x
x.remove(13)
x[23, 9, 7, 9, 19]4.6 count(): Count occurences of a value in the list
x.count(9)24.7 copy(): make a (shallow) copy of the list
z = x.copy()
z[23, 9, 7, 9, 19]4.8 reverse(): Reverse elements in-place
x.reverse()4.9 sort(): sort list in-place
Defaults to ascending order
x.sort()
x[7, 9, 9, 19, 23]5 sort in descending order with reverse:
x.sort(reverse=True)
x[23, 19, 9, 9, 7]5.1 clear(): remove all list items
x.clear()
x[]5.2 2-D List
x = [[1, 3, 5], [21, 25, 29]]
x[[1, 3, 5], [21, 25, 29]]len(x)25.3 Repeat and append with * and +
["A", "B"] * 3['A', 'B', 'A', 'B', 'A', 'B'][21, 22] + [31, 32][21, 22, 31, 32][1, 2] * 2 + [3, 4] * 3[1, 2, 1, 2, 3, 4, 3, 4, 3, 4]