Given a python .pyc file, is there a tool that let me view the bytecode?

Question

A Python module is automatically compiled into a .pyc file by CPython interpreter. The .pyc file, which contains the bytecode, is in binary format (marshaled code?). Is there a GUI (or command line) tool that let me view the bytecode?

Answer 1

Extending the code form @PADYMKO based on @Apteryx 's note about the PEP:

def view_pyc_file(path):
    """Read and display a content of the Python`s bytecode in a pyc-file."""

    file = open(path, 'rb')

    magic = file.read(4)
    bit_field = None
    timestamp = None
    hashstr = None
    size = None

    if sys.version_info.major == 3 and sys.version_info.minor >=7:
        bit_field = int.from_bytes(file.read(4), byteorder=sys.byteorder)
        if 1 & bit_field == 1:
            hashstr = file.read(8)
        else:
            timestamp = file.read(4)
            size = file.read(4)
            size = struct.unpack('I', size)[0]
    elif sys.version_info.major == 3 and sys.version_info.minor >= 3:
        timestamp = file.read(4)
        size = file.read(4)
        size = struct.unpack('I', size)[0]
    else:
        timestamp = file.read(4)

    code = marshal.load(file)

    magic = binascii.hexlify(magic).decode('utf-8')
    timestamp = time.asctime(time.localtime(struct.unpack('I', b'D\xa5\xc2X')[0]))

    dis.disassemble(code)

    print('-' * 80)
    print(
        'Python version: {}\nMagic code: {}\nTimestamp: {}\nSize: {}\nHash: {}\nBitfield: {}'
        .format(platform.python_version(), magic, timestamp, size, hashstr, bit_field)
    )

    file.close()