list

The built-in list type. Example list expressions:

x = [1, 2, 3]

Accessing elements is possible using indexing (starts from 0):

e = x[1]   # e == 2

Lists support the + operator to concatenate two lists. Example:

x = [1, 2] + [3, 4]   # x == [1, 2, 3, 4]
x = ["a", "b"]
x += ["c"]            # x == ["a", "b", "c"]

Similar to strings, lists support slice operations:

['a', 'b', 'c', 'd'][1:3]   # ['b', 'c']
['a', 'b', 'c', 'd'][::2]  # ['a', 'c']
['a', 'b', 'c', 'd'][3:0:-1]  # ['d', 'c', 'b']

Lists are mutable, as in Python.

Members

• append
• clear
• extend
• index
• insert
• pop
• remove

append

None list.append(item)

Adds an item to the end of the list.

Parameters

Parameter	Description
item	required

clear

None list.clear()

Removes all the elements of the list.

extend

None list.extend(items)

Adds all items to the end of the list.

Parameters

Parameter	Description
items	iterable; required

index

int list.index(x, start=unbound, end=unbound)

Returns the index in the list of the first item whose value is x. It is an error if there is no such item. If start and end are given, they restrict the range searched in the same manner as slicing.

Parameters

Parameter	Description
x	required
start	int; default is unbound The start index of the list portion to inspect.
end	int; default is unbound The end index of the list portion to inspect.

insert

None list.insert(index, item)

Inserts an item at a given position.

Parameters

Parameter	Description
index	int; required The index the item will be at after insertion. If the index is out of range, it’s transformed into an effective index in the range from 0 to the list’s previous length, inclusive, in the same manner as for the start index of a slice operator.
item	required The item.

pop

unknown list.pop(i=-1)

Removes the item at the given position in the list, and returns it. If no index is specified, it removes and returns the last item in the list.

Parameters

Parameter	Description
i	int; default is -1 The index of the item.

remove

None list.remove(x)

Removes the first item from the list whose value is x. It is an error if there is no such item.

Parameters

Parameter	Description
x	required The object to remove.