Use the list sort() method to sort a list with a lambda expression in Python. Just call the list.sort(key=None) with a key set to a lambda expression to sort the elements of the list by the key.
Both list.sort() and sorted() have a key parameter to specify a function to be called on each list element prior to making comparisons.
Example sort lambda in Python
Simple example code, sorting the data by index value 0.
data = [("B", 5, "20"), ("A", 1, "5"), ("C", 6, "10")]
data.sort(key=lambda x: x[0])
print(data)
Output:
Another example with the sorted() method
Here is code to sort through its “integers”.
ids = ['id5', 'id1', 'id2', 'id5', 'id4', 'id3']
res = sorted(ids, key=lambda x: int(x[2:]))
print(res)Output: [‘id1’, ‘id2’, ‘id3’, ‘id4’, ‘id5’, ‘id5’]
Revere sort the list using lambda
ids = [5, 2, 3, 1, 4]
res = sorted(ids, key=lambda x: x, reverse=True)
print(res)
Output: [5, 4, 3, 2, 1]
Do comment if you have any doubts or suggestions on this Python lambda tutorial.
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.