The find() method of bytearray class in Python

Overview:

• For a given subsequence, the find() method of bytearray class in Python returns the index of its first occurrence.
• When a range of positions is provided by specifying the positions “after” and “before”, the find() method returns the index of the first occurrence within this range.
• When no occurrence of the subsequence is found the find() method returns -1.

Example 1 - Find the position of a subsequence in a bytearray:

# Example Python program that finds the
# first occurrence of a subsequence from a bytearray

# Create a bytearray
buffer = bytearray(b"if it was so, it might be")

# The type of subsequence is bytes
subsequence = b"it"

# Find the first occurence of a substring
pos = buffer.find(subsequence)

print("Position of the subsequence in the bytearray:")
print(pos)

Output:

Position of the subsequence in the bytearray:
3

Example 2 - Find a subsequence in a bytearray between a range of positions:

# Example Python program that finds the
# occurrence of a subsequence within a given range
# of positions after and before

buffer = bytearray(b"I knew who I was this morning, but I have changed")
sequence2Find = bytearray(b"I")
after = 5
before = 15

# Find the position of a subsequence between the positions after
# and before
pos = buffer.find(sequence2Find, after, before)
print("Subsequence position between index {} and {}:".format(after, before))
print(pos)

# Find the position of a subsequence in the slice[15, len(buffer)]
after = 15
pos = buffer.find(sequence2Find, after)
print("Position of the subsequence after index {}:".format(after))
print(pos)

Output:

Subsequence position between index 5 and 15:
11
Position of the subsequence after index 15:
35