Python List sort() method
The list.sort
() method in Python sorts the items of the list in place.
Syntax
list.sort(key=None, reverse=False)
Parameter
reverse: If a Boolean value ‘True’ is passed, the sorting will be done in the descending order else for ‘False’ Boolean value sorting is done in ascending order.
key: This parameter represents a function to specify the sorting criteria(s)
Example 1
# Python program explaining # the list.sort() method # passing the alphabets list alphaList = ['b', 'a', 'e', 'd', 'c'] print("Actual list: ",alphaList) # sort the alphabets list in the ascending order alphaList.sort() # priningt the list in a sorted order print('Sorted list:',alphaList)
Output
List: ['b', 'a', 'e', 'd', 'c'] Sorted list: ['a', 'b', 'c', 'd', 'e']
Example 2
# Python program explaining # the list.sort() method weekList = ['Sun', 'Thurs', 'Mon', 'Fri', 'Tues', 'Wed'] print("Actual week list: ",weekList) # Sorting the week list in the descending order weekList.sort(reverse=True) # printing the sorted week list print("Sorted week list:",weekList)
Output
Actual week list: ['Sun', 'Thurs', 'Mon', 'Fri', 'Tues', 'Wed'] Sorted week list: ['Wed', 'Tues', 'Thurs', 'Sun', 'Mon', 'Fri']
Example 3
# Python program explaining # the list.sort() method # returning the second element of the parameter def sortArray(arr): return arr[1] # demonstrating the use of sorting by using using the second key valList = [(11, 12), (13, 13), (11, 11)] # sorting the array in ascending valList.sort(key = sortArray, reverse = False) # printing the sorted array print("Sorted array in ascending order: \n",valList) # sorting the array in descending valList.sort(key = sortArray, reverse = True) # printing the sorted array print("Sorted array in descending order: \n",valList)
Output
Sorted array in ascending order: [(11, 11), (11, 12), (13, 13)] Sorted array in descending order: [(13, 13), (11, 12), (11, 11)]