Python2.7 'set -x' alike

setx.py

# Use like: python setx.py my_python_program [args...]
#
# my_python_program can be a literal path to a file (e.g., foo.py), or the unqualified
# name of a Python program in PATH.  In the latter case, setx.py examines PATH for
# a program with that name.
#
# Prints every line executed, including the filename and line number.
#
# This is a hacky prototype for py27; it almost certainly breaks in significant ways on
# non-Unix, or Python3000; and has only been tested on a FreeBSD derivative.  It still
# may be interesting or a useful starting point for more portable implementations.

import bdb
import linecache
import os
import os.path
import sys
import __main__

skip_module_imports = True
log_exceptions = False
log_calls = False

class Xdb(bdb.Bdb):
    def runfile(self, prog):
        self._myprog = prog
        self.run('execfile("%s")' % prog)

    def user_call(self, frame, args):
        if not log_calls:
            return

        name = frame.f_code.co_name
        if not name:
            name = '???'
        fn = self.canonic(frame.f_code.co_filename)
        print '+++ call', fn, frame.f_lineno, name, args

    def user_line(self, frame):
        import linecache
        name = frame.f_code.co_name
        if not name:
            name = '???'
        fn = self.canonic(frame.f_code.co_filename)
        if fn == "<string>":
            return
        if "python2.7/sre_parse.py" in fn or "python2.7/sre_compile.py" in fn:
            return
        line = linecache.getline(fn, frame.f_lineno, frame.f_globals)
        line = line.strip()

        if skip_module_imports and line.startswith("import "):
            self.set_next(frame)
        else:
            self.set_step()

        print '+++', fn, frame.f_lineno, name, ':', line

    def user_return(self, frame, retval):
        if not log_calls:
            return

        print '+++ return', retval

    def user_exception(self, frame, exc_stuff):
        if not log_exceptions:
            return

        print '+++ exception', exc_stuff

def lookup(prog):
    for d in os.environ.get("PATH", "").split(":"):
        if not os.path.isdir(d):
            continue
        t = d + "/" + prog
        if os.path.exists(t):
            return t

    import errno
    raise FileNotFoundError(errno.ENOENT, prog)

if __name__ == "__main__":
    del sys.argv[0]
    prog = sys.argv[0]

    if not os.path.exists(prog) and prog[0] != '/':
        prog = lookup(prog)

    sys.path[0] = os.path.dirname(os.path.realpath(prog))
    __main__.__file__ = prog
    Xdb().runfile(prog)