Detailed explanation of the usage of sort() function in python

The usage of the sort() function in python is a function that sorts the list. It can sort the elements in the list in ascending or descending order. The syntax is "list.sort(key=None, reverse=False)". key: Specifies the comparison function used for sorting. The default value is None, which means the default comparison function is used for sorting. reverse: Specify the sorting order. The default value is False, which means sorting in ascending order, etc.

#The sort() function is a function used in Python to sort a list. It can sort the elements in the list in ascending or descending order. The syntax of the sort() function is as follows:

list.sort(key=None, reverse=False)

- key: Specifies the comparison function used for sorting. The default value is None, which means using the default comparison function for sorting.

- reverse: Specify the order of sorting. The default value is False, which means sorting in ascending order.

2. Examples of using the sort() function

1. Sort the list in ascending order:

numbers = [5, 2, 8, 1, 9]
numbers.sort()
print(numbers)

In this example, we define a list of numbers containing integers. . By calling the sort() function, we successfully sort the elements in the list in ascending order and print the result:

[1, 2, 5, 8, 9]

2. Sort the list in descending order:

numbers = [5, 2, 8, 1, 9]
numbers.sort(reverse=True)
print(numbers)

In this example , we use the reverse parameter to set the sort order to descending order. After calling the sort() function, we successfully sort the elements in the list in descending order and print the result:

[9, 8, 5, 2, 1]

3. Use a custom comparison function to sort:

def compare_length(element):
    return len(element)
fruits = ['apple', 'banana', 'cherry', 'dragon fruit']
fruits.sort(key=compare_length)
print(fruits)

In In this example, we define a comparison function compare_length, which returns the length of a string. By passing this function to the key parameter, we can sort the elements in the list by the length of the string. After calling the sort() function, we successfully sorted the list according to the length of the string and printed the result:

['apple', 'cherry', 'banana', 'dragon fruit']

3. Notes

When using the sort() function, There are several things to note:

1. The sort() function will directly modify the original list without returning a new list. Therefore, before calling the sort() function, it is best to back up the original list to prevent accidental modification.

2. The sort() function uses Python's default comparison function for sorting by default. For numbers and strings, their comparison rules are in lexicographic order. For other types of objects, a custom comparison function may be required.

3. If you need to customize the sorting of the elements in the list, you can specify a comparison function through the key parameter. The comparison function should accept one parameter and return a value for comparison. Sort based on this value.

4. If you need to sort in descending order, you can set the reverse parameter to True. By default, the sort() function sorts in ascending order.

4. Summary

Through the introduction of this article, we have learned about the usage of the sort() function in Python. It is a function that sorts a list, and can sort the elements in the list in ascending or descending order. We learned the syntax of functions, usage examples, and precautions. Mastering the use of the sort() function, we can better sort the list and make the data more orderly and easier to process.

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