python中使用sys模板和logging模块获取行号和函数名的方法

def currentframe():
"""Return the frame object for the caller's stack frame."""
try:
raise Exception
except:
return sys.exc_info()[2].tb_frame.f_back
def findCaller(self):
"""
Find the stack frame of the caller so that we can note the source
file name, line number and function name.
"""
f = currentframe()
#On some versions of IronPython, currentframe() returns None if
#IronPython isn't run with -X:Frames.
if f is not None:
f = f.f_back
rv = "(unknown file)", 0, "(unknown function)"
while hasattr(f, "f_code"):
co = f.f_code
filename = os.path.normcase(co.co_filename)
if filename == _srcfile:
f = f.f_back
continue
rv = (co.co_filename, f.f_lineno, co.co_name)
break
return rv
def _log(self, level, msg, args, exc_info=None, extra=None):
"""
Low-level logging routine which creates a LogRecord and then calls
all the handlers of this logger to handle the record.
"""
if _srcfile:
#IronPython doesn't track Python frames, so findCaller throws an
#exception on some versions of IronPython. We trap it here so that
#IronPython can use logging.
try:
fn, lno, func = self.findCaller()
except ValueError:
fn, lno, func = "(unknown file)", 0, "(unknown function)"
else:
fn, lno, func = "(unknown file)", 0, "(unknown function)"
if exc_info:
if not isinstance(exc_info, tuple):
exc_info = sys.exc_info()
record = self.makeRecord(self.name, level, fn, lno, msg, args, exc_info, func, extra)
self.handle(record)

我简单解释一下，实际上是通过在currentframe函数中抛出一个异常，然后通过向上查找的方式，找到调用的信息。其中