bytes.find(sub[, start[, end]])
bytearray.find(sub[, start[, end]])
Return the lowest index in the data where the subsequence sub is found, such that sub is contained in the slice s[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 if sub is not found.
The subsequence to search for may be any bytes-like object or an integer in the range 0 to 255.
Note The find() method should be used only if you need to know the position of sub. To check if sub is a