monkey patch stderr and stdout to show call stack when a specific print statement occurs.

find_print.py

import sys
class fake_out:
    def __init__(self, stream):
        self._stream = stream
        for name in dir(stream):
            if name != "write" and not name.startswith("_"):
                setattr(self, name, getattr(stream, name))
    def write(self, s):
        self._stream.write(s)
        if "enter your password" in s.lower():
            raise ValueError("woah %r" % s)
sys.stdout = fake_out(sys.stdout)
sys.stdout = fake_out(sys.stderr)