Python list() is a constructor, which returns a list. If no parameters are passed in the constructor, it returns an empty list. With iterable, it creates a list consisting of iterable’s items.
list([iterable])It can be used in different ways to convert an iterable or other data type into a list.
Here are some common usages of the list() function:
Converting an iterable to a list:
iterable = [1, 2, 3, 4, 5]
new_list = list(iterable)
print(new_list) # [1, 2, 3, 4, 5]
Creating a list from a string:
text = "Hello, World!"
char_list = list(text)
print(char_list) # ['H', 'e', 'l', 'l', 'o', ',', ' ', 'W', 'o', 'r', 'l', 'd', '!']
Creating an empty list:
empty_list = list()
print(empty_list) # []
Converting a tuple to a list:
my_tuple = (1, 2, 3)
converted_list = list(my_tuple)
print(converted_list) # [1, 2, 3]
Copying an existing list:
original_list = [1, 2, 3]
copied_list = list(original_list)
print(copied_list) # [1, 2, 3]
The list() function is quite versatile and can be used to convert various data types to lists. It’s worth noting that if you pass a single argument to the list() function, it must be an iterable (e.g., string, tuple, set, dictionary keys) that can be converted to a list.
Python list() Example
Simple example code.
If you want to create a literal new list with a bunch of new values then you’re right. There is no reason to use the list constructor, you should use the literal notation:
my_list = ['a', 'b', 'c']Use it to transform iterables into their list representation:
my_tuple = ('a', 'b', 'c') # create a new tuple
my_list = list(my_tuple) # Convert into a list
print(my_list)
print(type(my_list))
Output:
You can use the other iterable constructors like set and dict in a similar way.
Python List/Array functions
List of built-in methods that you can use on lists/arrays.
| Method | Description |
|---|---|
| append() | Adds an element at the end of the list |
| clear() | Removes all the elements from the list |
| copy() | Returns a copy of the list |
| count() | Returns the number of elements with the specified value |
| extend() | Add the elements of a list (or any iterable), to the end of the current list |
| index() | Returns the index of the first element with the specified value |
| insert() | Adds an element at the specified position |
| pop() | Removes the element at the specified position |
| remove() | Removes the first item with the specified value |
| reverse() | Reverses the order of the list |
| sort() | Sorts the list |
Do comment if you have any doubts or suggestions on this Python basic topic.
Note: IDE: PyCharm 2021.3.3 (Community Edition)
Windows 10
Python 3.10.1
All Python Examples are in Python 3, so Maybe its different from python 2 or upgraded versions.