The zfill() method of bytearray class in Python

Overview:

The zfill() method returns a new bytearray object of a given size which is zero-filled on the left side. The zfill() returns a zero padded bytearray on the left side, only when the given size is greater than the current size of the bytearray. If the given size is less than the current size, a copy of the original bytearray is returned without any modification.

The zfill() method of bytearray in Python

Though the resize() and zfill() methods are about changing the size of a bytearray the following are the differences between them:

	The zfill() method	The resize() method
When buffer less than current size	When a size less than the current size is specified the zfill() method returns the copy of the original bytearray.	The reset method will reduce the size of the original bytearray when a size less than the current size is specified.
Zero fill location	The zfill() method zero-fills on the left side of the bytearray and returns the new bytearray. The original bytearray is not modified.	When the size given is greater than current size it zero-fills the left side of the original bytearray.
Copy vs actual bytearray	Changes are made to the copy of the bytearray.	Changes are made to the original bytearray.

Example:

# Example Python program that creates a new
# bytearray of greater length which is zero-filled
# on the front

# Create a bytearray
buffer = bytearray(b"The lazy brown fox")

# Create a new bytearray which is zfilled
# on the front
zfilled = buffer.zfill(len(buffer) + 4)

print("Original bytearray:")
print(buffer)
print("Id:{}".format(id(buffer)))

print("The zfilled bytearray:")
print(zfilled)
print("Id:{}".format(id(zfilled)))

Output:

Original bytearray:
bytearray(b'The lazy brown fox')
Id:4340038960
The zfilled bytearray:
bytearray(b'0000The lazy brown fox')
Id:4340038896