我有一个这样的函数...
def validate_phone(raw_number, debug=False):
我想让debug标志控制它是否输出日志语句。例如：
if (debug):
print('Before splitting numbers', file=sys.stderr)
split_version = raw_number.split('-')
if (debug):
print('After splitting numbers', file=sys.stderr)
然而，那段代码非常重复。如何以最简洁（最DRY？）的方式处理这种if-标志-然后记录逻辑？
我认为在运行 Python 脚本时，使用日志记录是打印调试信息的最佳解决方案。我编写了一个 DebugPrint 模块，帮助更轻松地使用日志记录：
#DebugPrint.py
import logging
import os
import time
DEBUGMODE=True
logging.basicConfig(level=logging.DEBUG)
log=logging.getLogger('=>')
#DebugPrint.py
#DbgPrint=logging.debug
def DbgPrint(*args, **kwargs):
if DEBUGMODE:
#get module, class, function, linenumber information
import inspect
className = None
try:
className = inspect.stack()[2][0].f_locals['self'].__class__.__name__
except:
pass
modName=None
try:
modName = os.path.basename(inspect.stack()[2][1])
except:
pass
lineNo=inspect.stack()[2][2]
fnName=None
try:
fnName = inspect.stack()[2][3]
except:
pass
DbgText="line#{}:{}->{}->{}()".format(lineNo, modName,className, fnName)
argCnt=len(args)
kwargCnt=len(kwargs)
#print("argCnt:{} kwargCnt:{}".format(argCnt,kwargCnt))
fmt=""
fmt1=DbgText+":"+time.strftime("%H:%M:%S")+"->"
if argCnt > 0:
fmt1+=(argCnt-1)*"%s,"
fmt1+="%s"
fmt+=fmt1
if kwargCnt>0:
fmt2="%s"
args+=("{}".format(kwargs),)
if len(fmt)>0:
fmt+=","+fmt2
else:
fmt+=fmt2
#print("fmt:{}".format(fmt))
log.debug(fmt,*args)
if __name__=="__main__":
def myTest():
print("Running myTest()")
DbgPrint("Hello","World")
myTest()
DEBUG:=>:16:24:14:line#78:DebugPrint.py->None->myTest():->Hello,World
#testDebugPrint.py
from DebugPrint import DbgPrint
class myTestClass(object):
def __init__(self):
DbgPrint("Initializing the class")
def doSomething(self, arg):
DbgPrint("I'm doing something with {}".format(arg))
if __name__=='__main__':
test=myTestClass()
test.doSomething("a friend!")
DEBUG:=>:16:25:02:line#7:testDebugPrint.py->myTestClass->__init__():->Initializing the class
DEBUG:=>:16:25:02:line#10:testDebugPrint.py->myTestClass->doSomething():->I'm doing something with a friend!
> cat a.py
import logging
log = logging.getLogger(__name__)
def main():
log.debug('This is debug')
log.info('This is info')
log.warn('This is warn')
log.fatal('This is fatal')
try:
raise Exception("this is exception")
except Exception:
log.warn('Failed with exception', exc_info=True)
raise
if __name__ == '__main__':
import argparse
parser = argparse.ArgumentParser(description='something')
parser.add_argument(
'-v', '--verbose', action='count', default=0, dest='verbosity')
args = parser.parse_args()
logging.basicConfig()
logging.getLogger().setLevel(logging.WARN - 10 * args.verbosity)
main()
> python a.py
WARNING:__main__:This is warn
CRITICAL:__main__:This is fatal
WARNING:__main__:Failed with exception
Traceback (most recent call last):
File "a.py", line 12, in main
raise Exception("this is exception")
Exception: this is exception
Traceback (most recent call last):
File "a.py", line 27, in <module>
main()
File "a.py", line 12, in main
raise Exception("this is exception")
Exception: this is exception
> python a.py -v
INFO:__main__:This is info
WARNING:__main__:This is warn
CRITICAL:__main__:This is fatal
WARNING:__main__:Failed with exception
Traceback (most recent call last):
File "a.py", line 12, in main
raise Exception("this is exception")
Exception: this is exception
Traceback (most recent call last):
File "a.py", line 27, in <module>
main()
File "a.py", line 12, in main
raise Exception("this is exception")
Exception: this is exception
> python a.py -vv
DEBUG:__main__:This is debug
INFO:__main__:This is info
WARNING:__main__:This is warn
CRITICAL:__main__:This is fatal
WARNING:__main__:Failed with exception
Traceback (most recent call last):
File "a.py", line 12, in main
raise Exception("this is exception")
Exception: this is exception
Traceback (most recent call last):
File "a.py", line 27, in <module>
main()
File "a.py", line 12, in main
raise Exception("this is exception")
Exception: this is exception
import logging
import sys
# Get the "root" level logger.
root = logging.getLogger()
# Set the log level to debug.
root.setLevel(logging.DEBUG)
# Add a handler to output log messages as a stream (to a file/handle)
# in this case, sys.stderr
ch = logging.StreamHandler(sys.stderr)
# This handler can log debug messages - multiple handlers could log
# different "levels" of log messages.
ch.setLevel(logging.DEBUG)
# Format the output to include the time, etc.
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
ch.setFormatter(formatter)
# Add the formatter to the root handler...
root.addHandler(ch)
# Get a logger object - this is what we use to omit log messages.
logger=logging.getLogger(__name__)
# Generate a bunch of log messages as a demonstration
for i in xrange(100):
logger.debug('The value of i is: %s', i)
# Demonstrate a useful example of logging full exception tracebacks
# if the logger will output debug, but a warning in other modes.
try:
a='a'+12
except Exception as e:
# Only log exceptions if debug is enabled..
if logger.isEnabledFor(logging.DEBUG):
# Log the traceback w/ the exception message.
logger.exception('Something went wrong: %s', e)
else:
logger.warning('Something went wrong: %s', e)
点击此处了解更多相关信息: https://docs.python.org/2/library/logging.html
要禁用日志记录，只需将级别（logging.DEBUG）设置为其他值（例如logging.INFO）。请注意，将消息重定向到其他地方（如文件）或将某些消息（调试）发送到某个地方，将其他消息（警告）发送到其他地方也很容易。
import logging
logging.basicConfig(filename='example.log',level=logging.DEBUG)
logging.debug('This message should go to the log file')
你可以更改日志级别为 INFO/DEBUG/WARNING/ERROR/CRITICAL，而且 logging 模块还可以为你记录时间戳，并且它也是可配置的。
logging模块？ - Haifeng Zhanglogging是正确答案），但您始终可以使用动态定义的函数。只需在函数内部执行以下操作：debugprint = print if debug else lambda *a, **k: None，然后在整个函数中使用debugprint来代替print进行调试打印；这样做会评估参数并产生函数调用开销，但在非调试模式下不会执行任何操作，在调试模式下则会打印输出。 - ShadowRanger