Sort

Why does a list not sort properly in Python as expected? There are a couple of reasons why a list may not have sorted as expected in Python. Here are a couple of ways to diagnose the problem to help you check. Here’s a quick list (no pun intended!) you can use to quickly check: Are all elements within the list of the same data type? Look at setting them to the same data type using the key parameter Are you capturing the result of a .sort() method? Change this sort operation to the sorted() function Are you sorting items with mixed case? Apply the key parameter converting all items to .lower() Do you understand the key parameter? Extract the lambda function to check it works on elements in your list. Are you sorting in reverse? Check the reverse parameter to your sort function. False is the default setting it this parameter is not defined. Are you sorting unicode characters? Look to use a standard encoding type with the key parameter using lambda x : x.encode('utf-8'). Are there any whitespace characters wrapping the elements? Apply the .strip() string method to each element with the key parameter. Let’s explore each of these items in a little more detail with examples. Here are some reasons why your Python lists may not be sorting properly: ...

How do you sort a Python list alphabetically? There are two easy ways to sort a list in Python: using the standard sorted() function or using the .sort() list method. Assuming you have a list of strings you can apply either method to sort the list alphabetically. If you have a list of numbers and strings you can use the parameter key to change all values within the list to a str data type and then perform the necessary sort (more on that later). ...

How do you sort a list of lists by the second element using Python? To sort a list of lists by the second element in each list use the key parameter to either the .sort() list function (if modifying the original list) or the sorted() function (if returning a new list). Here’s an example demonstrating how you can do this with code: 1 2 3 4 >>> list_2d = [['2nd', 2], ['3rd', 3], ['1st', 1]] >>> list_2d.sort(key=lambda x: x[1]) >>> print(list_2d) [['1st', 1], ['2nd', 2], ['3rd', 3]] As you can see from the above code the key parameter in the .sort() list function uses a lambda expression which takes each list and extracts the second element. This is used as the key to determine how each list will be sorted. ...