python: get the print output in an exec statement

Question

I want to get the output of an exec(...) Here is my code:

code = """
i = [0,1,2]
for j in i :
    print j
"""
result = exec(code)

How could I get the things that print outputed? How can I get something like:

0
1
2

Regards and thanks.

Answer 1

Since Python 3.4 there is a solution is the stdlib: https://docs.python.org/3/library/contextlib.html#contextlib.redirect_stdout

from io import StringIO
from contextlib import redirect_stdout

f = StringIO()
with redirect_stdout(f):
    help(pow)
s = f.getvalue()

In older versions you can write a context manager to handle replacing stdout:

import sys
from io import StringIO
import contextlib

@contextlib.contextmanager
def stdoutIO(stdout=None):
    old = sys.stdout
    if stdout is None:
        stdout = StringIO()
    sys.stdout = stdout
    yield stdout
    sys.stdout = old

code = """
i = [0,1,2]
for j in i :
    print j
"""
with stdoutIO() as s:
    exec(code)

print("out:", s.getvalue())