Method Signature:
rotate(n)
Parameters:
n - Number of times the deque needs to be rotated.
Return value:
None
Method Overview:
- The rotate() method of python deque class rotates the sequence present in the deque object ‘n’ times.
- If no parameter is passed ‘n’ will have the default value of 1.
- If ‘n’ is negative rotation direction is right to left.
- If ‘n’ is positive rotation direction is left to right.
- The rotate() method does not return a copy of the deque which has the new sequence. Instead, rotation is applied on the contents of the deque object itself.
Example 1 – Rotate the Python Deque Object positive number of times:
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import collections
# Create an empty deque object dequeObject = collections.deque()
# Add elements to the deque - left to right dequeObject.append(1) dequeObject.append(3) dequeObject.append(6) dequeObject.append(10)
# Print the deque contents print("Deque before any rotation:") print(dequeObject)
# Rotate once in positive direction dequeObject.rotate()
print("Deque after 1 positive rotation:") print(dequeObject)
# Rotate twice in positive direction dequeObject.rotate(2)
print("Deque after 2 positive rotations:") print(dequeObject) |
Output:
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Deque before any rotation: deque([1, 3, 6, 10]) Deque after 1 positive rotation: deque([10, 1, 3, 6]) Deque after 2 positive rotations: deque([3, 6, 10, 1]) |
The output shows that effectively 3 positive rotations applied on the sequence of elements present in the deque object.
Example 2 – Rotate the Python Deque Object negative number of times:
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import collections
# Create a tuple sequence = (1, 2, 4, 8, 16, 32)
# Create a deque from the tuple sequenceInDeque = collections.deque(sequence)
# Print the contents of the deque object print("Deque before any rotation:") print(sequenceInDeque)
# Rotate once - in negative direction sequenceInDeque.rotate(-1)
print("Deque after 1 negative rotation:") print(sequenceInDeque)
# Rotate twice - in negative direction sequenceInDeque.rotate(-2)
print("Deque after 2 negative rotations:") print(sequenceInDeque) |
Output:
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Deque before any rotation: deque([1, 2, 4, 8, 16, 32]) Deque after 1 negative rotation: deque([2, 4, 8, 16, 32, 1]) Deque after 2 negative rotations: deque([8, 16, 32, 1, 2, 4]) |
The output shows that effectively 3 negative rotations applied on the sequence of elements present in the deque object.