def disassembler(co, lasti= -1):
"""Disassemble a code object.
:param co: code object
:param lasti: internal
:yields: Instructions.
"""
code = co.co_code
labels = findlabels(code)
linestarts = dict(findlinestarts(co))
n = len(code)
i = 0
extended_arg = 0
lineno = 0
free = None
while i < n:
c = code[i]
op = co_ord(c)
if i in linestarts:
lineno = linestarts[i]
instr = Instruction(i=i, op=op, lineno=lineno)
instr.linestart = i in linestarts
if i == lasti:
instr.lasti = True
else:
instr.lasti = False
if i in labels:
instr.label = True
else:
instr.label = False
i = i + 1
if op >= opcode.HAVE_ARGUMENT:
oparg = co_ord(code[i]) + co_ord(code[i + 1]) * 256 + extended_arg
instr.oparg = oparg
extended_arg = 0
i = i + 2
if op == opcode.EXTENDED_ARG:
extended_arg = oparg * 65536
instr.extended_arg = extended_arg
if op in opcode.hasconst:
instr.arg = co.co_consts[oparg]
elif op in opcode.hasname:
instr.arg = co.co_names[oparg]
elif op in opcode.hasjrel:
instr.arg = i + oparg
elif op in opcode.haslocal:
instr.arg = co.co_varnames[oparg]
elif op in opcode.hascompare:
instr.arg = opcode.cmp_op[oparg]
elif op in opcode.hasfree:
if free is None:
free = co.co_cellvars + co.co_freevars
instr.arg = free[oparg]
yield instr
