Contenido del Curso
Intermediate Python Techniques
Intermediate Python Techniques
Built-in Functions
Here are two more examples demonstrating the use of lambda functions with the filter()
and sorted()
functions in Python.
Alternatively, you can pass a more complex custom function instead of a lambda to these high-order functions.
filter()
The filter()
function is used to create an iterator from elements of an iterable for which a function returns true. Here's an example using filter() with a lambda function to filter out odd numbers from a list:
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] # Using a lambda function to filter out odd numbers even_numbers = filter(lambda x: x % 2 == 0, numbers) # Convert the filter object to a list even_numbers_list = list(even_numbers) print(even_numbers_list)
In this example, the lambda function lambda x: x % 2 == 0
checks if a number is even. The filter()
function applies this lambda to each element in the list of numbers and returns an iterator of even numbers.
sorted()
The sorted()
function returns a new sorted list from the elements of any iterable.
iterable
is the sequence to sort (list, dict, tuple, etc);key
is a function to execute to decide the order;reverse
is a boolean. False is an ascending order, and True is descending. The default is False.
Here's an example using sorted()
with a lambda function to sort a list of tuples based on the second element in each tuple:
tuples = [(1, 'banana'), (2, 'apple'), (3, 'orange')] # Using a lambda function to sort by the second element of each tuple sorted_tuples = sorted(tuples, key=lambda x: x[1]) print(sorted_tuples)
In this example, the lambda function lambda x: x[1]
returns the second element of each tuple. The sorted()
function then sorts the list tuples based on these second elements, resulting in a list sorted alphabetically by the fruit names.
Swipe to show code editor
Let's consider a list of dictionaries representing books, and you want to filter out books that have a certain number of pages.
- Define the list of books.
books
is a list of dictionaries. Each dictionary represents a book with two keys: "title" and "pages". - Creating the custom function
has_many_pages
that acceptsbook
andmin_pages
arguments. - Use
filter()
with the custom function. - Converte the filter object to a list, store it to the
filtered_books_list
variable, and print it.
¡Gracias por tus comentarios!
Built-in Functions
Here are two more examples demonstrating the use of lambda functions with the filter()
and sorted()
functions in Python.
Alternatively, you can pass a more complex custom function instead of a lambda to these high-order functions.
filter()
The filter()
function is used to create an iterator from elements of an iterable for which a function returns true. Here's an example using filter() with a lambda function to filter out odd numbers from a list:
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] # Using a lambda function to filter out odd numbers even_numbers = filter(lambda x: x % 2 == 0, numbers) # Convert the filter object to a list even_numbers_list = list(even_numbers) print(even_numbers_list)
In this example, the lambda function lambda x: x % 2 == 0
checks if a number is even. The filter()
function applies this lambda to each element in the list of numbers and returns an iterator of even numbers.
sorted()
The sorted()
function returns a new sorted list from the elements of any iterable.
iterable
is the sequence to sort (list, dict, tuple, etc);key
is a function to execute to decide the order;reverse
is a boolean. False is an ascending order, and True is descending. The default is False.
Here's an example using sorted()
with a lambda function to sort a list of tuples based on the second element in each tuple:
tuples = [(1, 'banana'), (2, 'apple'), (3, 'orange')] # Using a lambda function to sort by the second element of each tuple sorted_tuples = sorted(tuples, key=lambda x: x[1]) print(sorted_tuples)
In this example, the lambda function lambda x: x[1]
returns the second element of each tuple. The sorted()
function then sorts the list tuples based on these second elements, resulting in a list sorted alphabetically by the fruit names.
Swipe to show code editor
Let's consider a list of dictionaries representing books, and you want to filter out books that have a certain number of pages.
- Define the list of books.
books
is a list of dictionaries. Each dictionary represents a book with two keys: "title" and "pages". - Creating the custom function
has_many_pages
that acceptsbook
andmin_pages
arguments. - Use
filter()
with the custom function. - Converte the filter object to a list, store it to the
filtered_books_list
variable, and print it.
¡Gracias por tus comentarios!