How do I create a Function object using a compiled Code object?

Question

So I have the following code.

code_string = """def f1(p1, p2, p3):
    print("a{}, b{}, c{}".format(p1, p2, p3))
def f2():
    print("text")
"""

code = compile(code_string, '<string>', 'exec')

f1 = code.co_consts[0]
f2 = code.co_consts[2]  # code.co_consts is the name of the prior function ("f1")

It compiles a string with some functions into a code object and then stores the code objects of the functions to separate variables.

What I want to know is how to create function objects using the code objects above so I can just call them.

So say ff1 = new_function(f1) where isinstance(ff1, types.FunctionType) would be True and I could just do ff1('a', 'b', 'c') to print "aa, bb, cc".

The code objects in f1 and f2 can be executed using exec. (Though I don't know how to pass arguments into f1 or make a bound method out of them this way)

Answer 1

You already extracted the code objects, now all you have to do is to create the functions objects using types.FuncitonType. It accepts:

1. Code object
2. Reference to the global module
3. Name

from types import FunctionType

code_string = """\
def f1(p1, p2, p3):
    print("a{}, b{}, c{}".format(p1, p2, p3))
def f2():
    print("text")
"""

code = compile(code_string, "<string>", "exec")

f1_code_object = code.co_consts[0]
f2_code_object = code.co_consts[1]

f1 = FunctionType(f1_code_object, globals(), "f1")
f2 = FunctionType(f2_code_object, globals(), "f2")
print(f1)
print(f2)
f1(10, 20, 30)
f2()

output:

<function f1 at 0x1042a2980>
<function f2 at 0x1042a2a20>
a10, b20, c30
text