Python Sort List in Reverse Order

How to sort a list in reverse order in Python? You can use the reverse=True on built-in sorted() function in Python to sort a list in reverse order. This method will return a new list after sorting a list. Alternatively, you can also use the sort() function with reverse=True to sort the list in reverse order, this updates the sort in place, meaning that it will modify the original list and you won’t need to create a new list.

1. Quick Examples of Sorting Lists in Reverse Order

If you are in a hurry, below are some quick examples of sorting lists in reverse order.


# Below are quick examples

# Example 1: sorted() - list in reverse order
technology = ['Java','Hadoop','Spark','Pandas','Pyspark','NumPy','Hyperion']
sorted_tech = sorted(technology, reverse=True)

# Example 2: sort() the list in reverse order
technology.sort(technology, reverse=True)

# Example 3: Sort the list in reverse order
technology.sort(technology, reverse=True)

2. Using sorted() to Order List in Reverse

The sorted() function with reverse=True in Python is used to sort a sequence (such as a list, tuple) in reverse order. The function returns a new sorted list, leaving the original sequence unchanged.

2.1 Sort Strings in Reverse Order Example

Here is an example of sorting lists of strings in reverse order.


# Sort list in reverse order
technology = ['Java','Hadoop','Spark','Pandas','Pyspark','NumPy','Hyperion']
print(technology)
sorted_tech = sorted(technology, reverse=True)
print(sorted_tech)

# Output
# ['Java','Hadoop','Spark','Pandas','Pyspark','NumPy','Hyperion']
# ['Spark', 'Pyspark', 'Pandas', 'NumPy', 'Java', 'Hyperion', 'Hadoop']

2.2 Sort Numbers in Reverse Order

Use param reverse=True to sort list of numbers in reverse order. Here is an example,


# Sort list of numbers in reverse order
numbers = [30,20,10,70,50,0]
print("Original: ",numbers)
sort_numbers = sorted(numbers, reverse=True)
print("Sorted:",sort_numbers)

# Output:
# Original:  [30, 20, 10, 70, 50, 0]
# Sorted: [70, 50, 30, 20, 10, 0]

3. Using sort() to Order List in Reverse

Similarly, you can also use the list.sort() function to order a list in reverse order. it also takes reverse as a parameter to specify whether the list should be sorted in ascending (False) or descending (True) order. The default is reverse=False. To sort in reverse use reverse=True.

3.1. Using sort() to Reverse Order Example

Here is an example of how you can use the sort method to order a list of strings in reverse order.


# Sort list in reverse order
technology = ['Java','Hadoop','Spark','Pandas','Pyspark','NumPy','Hyperion']
print(technology)
technology.sort(technology, reverse=True)
print(technology)

# Output
# ['Java','Hadoop','Spark','Pandas','Pyspark','NumPy','Hyperion']
# ['Spark', 'Pyspark', 'Pandas', 'NumPy', 'Java', 'Hyperion', 'Hadoop']

3.2 Sort Numbers in Reverse Order

To sort a list of numbers in reverse order use the sort() method with the reverse argument set its value to reverse=True.


# Sort list of numbers by reverse order
numbers = [30,20,10,70,50,0]
print("Original: ",numbers)
numbers.sort()
print("Sorted:",numbers)

# Output:
# Original:  [30, 20, 10, 70, 50, 0]
# Sorted: [70, 50, 30, 20, 10, 0]

4. Sort a List with Numbers as String in Reverse Order

If you have a list with a number but in string type and wanted to sort in reverse order, first you need to convert it to int type by using key=int to sort() or sorted() functions.

Note that, here the sorted list will be of string type but the data is numerically sorted by ascending order.


# Sort list of strings with numbers
# Using sorted()
numbers = ["30","20","10","70","50","0"]
print("Original: ",numbers)
sprt_numbers = sorted(numbers, key=int, reverse=True)
print("Sorted:",sprt_numbers)


# Using sort()
numbers = ["30","20","10","70","50","0"]
print("Original: ",numbers)
numbers.sort(key=int, reverse=True)
print("Sorted:",numbers)

# Output:
# Original:  ['30', '20', '10', '70', '50', '0']
# Sorted: ['70', '50', '30', '20', '10', '0']

Conclusion

In this article, I have explained how to sort a list in reverse order, First, I have covered using sorted() function and then list.sort(). To sort in reverse, both these functions take reverse=True as an argument.

Happy Learning !!

NNK

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