Flask Python Logging: TypeError while logging file path in File

Question

I'm trying to add content of variable "log_location" to current logger.

log_location = log_folder_location + os.path.sep + log_file_name
logger.debug("log location", str(log_location))
print "log_location: ",log_location

this prints to console, but gives error in logging,

Traceback (most recent call last):
  File "/usr/lib64/python2.6/logging/__init__.py", line 784, in emit
    msg = self.format(record)
  File "/usr/lib64/python2.6/logging/__init__.py", line 662, in format
    return fmt.format(record)
  File "/usr/lib64/python2.6/logging/__init__.py", line 444, in format
    record.message = record.getMessage()
  File "/usr/lib64/python2.6/logging/__init__.py", line 314, in getMessage
    msg = msg % self.args
TypeError: not all arguments converted during string formatting

it prints to,

log_location:  /U01/Nova/Logs/DEV-INT/TEST/validation_20170203-164617-5.log

This error is not happening in when I try in normal python prompt but facing same when using Flask

I've tried Logging Python stdout to File... with active stdout (backspacing/updating) and TypeError: not all arguments converted during string formatting python and this one too Python: Logging TypeError: not all arguments converted during string formatting

But did not understand what to do. Can someone explain this using simpler language, not like the documentation?

What Python version are you using? maybe there are unicode issues? what type are log_folder_location and log_file_name? — bastian, Feb 03 '17 at 12:11

Nikolay Prokopyev · Accepted Answer · 2017-02-07T09:42:22.927

Use only one argument to logger.debug() method call. I.e.

logger.debug("log location: " + str(log_location))

About the autoformatting feature (I don't think you need this, but for the completeness sake) - let's look from the docs:

Logger.debug(msg, *args, **kwargs)

Logs a message with level DEBUG on this logger. The msg is the message format string, and the args are the arguments which are merged into msg using the string formatting operator. (Note that this means that you can use keywords in the format string, together with a single dictionary argument.)

So, multiple arguments are useful when you have formatting template in the first arg, for example

logger.debug('log location: %s', log_location)

Yes, this was the right way, in fact I used logger above this code, & forgot to remove " , ", when changing print stmts to logger.debug..Now I think about it, I feel stupid to ask this...but yes, Thanx a lot this solves the issue(tested). — ajit junghare, Feb 03 '17 at 14:58

Flask Python Logging: TypeError while logging file path in File

1 Answers1