Python Language List: Difference between revisions

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=Overview=
=Overview=
A list is a mutable [[Python_Language#Sequence_Types|sequence type]] that contains zero or more elements and whose elements can be of different types.
A list is a mutable [[Python_Language#Sequence_Types|sequence type]] that contains zero or more elements and whose elements can be of different types.
=List <tt>type()</tt>=
The function <code>type()</code> applied to a list returns:
<font size=-1>
<class 'list'>
</font>
To check whether an instance is a list:
<syntaxhighlight lang='py'>
i = ...
if type(i) is list:
  ...
</syntaxhighlight >
For <code>list</code> subclasses:
<syntaxhighlight lang='py'>
i = ...
if isinstance(i, list):
  ...
</syntaxhighlight >
=Access to a List=
=Access to a List=
==Size of a List==
==Size of a List==

Revision as of 01:29, 3 March 2022

Internal

Overview

A list is a mutable sequence type that contains zero or more elements and whose elements can be of different types.

List type()

The function type() applied to a list returns: <class 'list'>

To check whether an instance is a list:

i = ...
if type(i) is list:
  ...

For list subclasses:

i = ...
if isinstance(i, list):
  ...

Access to a List

Size of a List

The number of elements is given by the len() function:

l = [...]
print(len(l))

Modify a List

Modify Individual Elements

Append an Element

l.append(e)

Delete the Last Element

del l[-1]

Assign the sublist to l:

l = l[:-1]

Delete All Elements

List Processing

Join the List Elements in a String

Join the elements of the given list in a string, using '-' as separator:

li = ['a', 'b']
s = '-'.join(li)