Slice Trick `[::-1]`: Reverse Lists and Strings

Reverse a list

nums = [1, 2, 3, 4, 5]
print(nums[::-1])

# [5, 4, 3, 2, 1]

Reverse a string

text = "Python"
print(text[::-1])

# nohtyP

Step slicing

nums = [0, 1, 2, 3, 4, 5, 6]
print(nums[::2])   # take every second
print(nums[::-2])  # reverse and take every second

# [0, 2, 4, 6]
# [6, 4, 2, 0]

Conclusion

The slice notation start:stop:step is powerful.
With [::-1], you get a quick and Pythonic way to reverse any sequence.