Python | Reverse each tuple in a list of tuples

Given a list of tuples, write a Python program to reverse each tuple in the given list of tuples.

Examples:

Input : [(1, 2), (3, 4, 5), (6, 7, 8, 9)]
Output : [(2, 1), (5, 4, 3), (9, 8, 7, 6)]

Input : [('a', 'b'), ('x', 'y'), ('m', 'n')]
Output : [('b', 'a'), ('y', 'x'), ('n', 'm')]

Method #1 : Negative-step slicing

We can use standard negative-step slicing tup[::-1] to get the reverse of a tuple, and a list comprehension to get that for each tuple.

# Python3 program to Reverse  
# each tuple in a list of tuples 
  
def reverseTuple(lstOfTuple): 
      
    return [tup[::-1] for tup in lstOfTuple] 
              
# Driver code 
lstOfTuple = [(1, 2), (3, 4, 5), (6, 7, 8, 9)] 
print(reverseTuple(lstOfTuple)) 

Output:

[(2, 1), (5, 4, 3), (9, 8, 7, 6)]

Method #2 : Using reversed()

The in-built reversed() method of Python can also be used to reverse each tuple within list.

# Python3 program to Reverse  
# each tuple in a list of tuples 
  
def reverseTuple(lstOfTuple): 
      
    return [tuple(reversed(tup)) for tup in lstOfTuple] 
              
# Driver code 
lstOfTuple = [(1, 2), (3, 4, 5), (6, 7, 8, 9)] 
print(reverseTuple(lstOfTuple)) 

Output:

[(2, 1), (5, 4, 3), (9, 8, 7, 6)]

Method #3 : Using map() function

Python map() function can also serve the purpose by mapping negative-step slicing to list of tuples.

# Python3 program to Reverse  
# each tuple in a list of tuples 
  
def reverseTuple(lstOfTuple): 
      
    return list(map(lambda tup: tup[::-1], lstOfTuple)) 
              
# Driver code 
lstOfTuple = [(1, 2), (3, 4, 5), (6, 7, 8, 9)] 
print(reverseTuple(lstOfTuple)) 

Output:

[(2, 1), (5, 4, 3), (9, 8, 7, 6)]

My Personal Notes

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