Formatting

Simber allows you to format the output messages as you want.

How to pass keywords

Simber allows the user to pass the special keywords just like it is passed to any Python string. For instance, if you want the levelname to be dynamically formatted during the runtime, then the string should be following

message_string = "{levelname} Just another message"

If the above string is passed as the format for the logger, during the runtime, a call to INFO method will print the following.

INFO Just another message

Special Keywords

Simber allows a certain number of special keywords that are formatted just before the message is written.

Supported keywords are:

Name	Keyword	Description
Time	time	Time as of printing the message. It will be of the form %d/%m/%Y %H:%M:%S by default and can be changed with the time_format param of logger.
Filename	filename	Name of the file that is printing this message
Function Name	funcname	Name of the function that is printing this message
Line Number	lineno	Line number of the current call in the file
Level Name	levelname	Level at which the logger is printing this message
Level Number	levelno	Level number at which the logger is printing this message
Logger Name	logger	Name of the logger that is printing this message
Message	message	Message passed by the user

Passing custom formats

In Simber, formats are specific to streams. So the format for each stream can vary, thus there is a need to pass custom formats. By leveraging the above keywords, pretty useful custom formats can be passed.

One thing to note is that, whatever custom message is passed by the user will be appended to this formatted string.

Default format

By default, Simber uses the following format for printing to stdout.

[{levelname}] [{logger}]

By using the above format with the info method as following

# Considering logger is an instance of Logger with name `Test`
logger.info("Printing a test message to stdout")

The output will be

[INFO] [Test] Printing a test message to stdout

Custom Format

We can passing a proper custom format in the following way.

Let's say, we want the following things in our logger message

• Level of the logger
• Name of the logger
• Name of the calling file
• Line number of the calling file

We can create a custom format including all the above in the following way.

from simber import Logger

custom_format = "[{levelname}] [{logger}] [{filename}] [{lineno}]"

# Now create an instance and pass the format
logger = Logger("Test", format=custom_format)

logger.info("Just a test statement")

Above will output the following

[INFO] [Test] [test.py] [4] Just a test statement

Advanced

Simber formatter module has a Formatter class that exposes a static method sub.

This method is used by the logger in order to format the code. The code of the method can be found here

If you want to override this method, a class can be made by inheriting the Formatter class and defining the sub method according to your wish, however, it is important to keep it a static method and preserving the paramaters that it accepts.