Hexdump in python

hexdump.py

def hexdump(byte_stream, encoding='utf-8', grouping=16):
    num_bytes = len(byte_stream)
    padding = (grouping-num_bytes%grouping)%grouping
    byte_stream += bytes(chr(0)*padding, encoding)
    def map_byte_to_readable_char(the_byte, valid_range=range(32,128), invalid_char='.'):
        return chr(the_byte) if the_byte in valid_range else invalid_char
    for row in range(0,len(byte_stream)//grouping):
        row_data  = [f"{byte_stream[row*grouping+n]:02x}" for n in range(0,grouping)]
        row_chars = [
            f"{map_byte_to_readable_char(byte_stream[row*grouping+n])}"
            for n in range(0,grouping)
        ]
        print(f"{row:06x}: {' '.join(row_data)}  {''.join(row_chars)}")

Revision 2 fixes an issue with groupings shorter than 16 characters, and creates a map_byte_to_readable_char function to make the row_chars list comprehension more readable.