from bitstring import ConstBitArray, BitStream  

# Opening from a file means that it won't be all read into memory
s = ConstBitArray(filename='test.ts')
outfile = open('test_nonull.ts', 'wb')

# Cut the stream into 188 byte packets
for packet in s.cut(188*8):
    # Take a 13 bit slice and interpret as an unsigned integer
    PID = packet[11:24].uint
    # Write out the packet if the PID doesn't indicate a 'null' packet
    if PID != 8191:
        # The 'bytes' property converts back to a string.
        outfile.write(packet.bytes)
	
# You can create from hex, binary, integers, strings, floats, files...
# This has a hex code followed by two 12 bit integers
s = BitStream('0x000001b3, uint:12=352, uint:12=288')

# Append some other bits
s += '0b11001, 0xff, int:5=-3'

# read back as 32 bits of hex, then two 12 bit unsigned integers
start_code, width, height = s.readlist('hex:32, 2*uint:12')

# Skip some bits then peek at next bit value
s.pos += 4
if s.peek(1):
    flags = s.read(9)
	
# Replace every '1' bit by 3 bits
s.replace('0b1', '0b001')

# Find all occurrences of a bit sequence
bitposlist = list(s.findall('0b01000'))

# Reverse bits in place
s.reverse()