Welcome to pysimplelog V. 4.0.0 documentation!

This is a pythonic simple yet complete system logger. It allows logging simultaneously to two streams, the first one is the system standard output by default and the second one is designated to be set to a file. In addition, pysimplelog is text colouring and attributes enabled when the stream allows it.

Installation guide:

pysimplelog is a pure python 2.7.x module that needs no particular installation. One can either fork pysimplelog’s github repository and copy the package to python’s site-packages or use pip as the following:

pip install pysimplelog
pysimplelog.get_version()

Get pysimplelog’s version number.

pysimplelog.get_author()

Get pysimplelog’s author’s name.

pysimplelog.get_email()

Get pysimplelog’s author’s email.

pysimplelog.get_doc()

Get pysimplelog’s official online documentation link.

pysimplelog.get_repository()

Get pysimplelog’s official online repository link.

pysimplelog.get_pypi()

Get pysimplelog pypi’s link.

Usage

# import python 2.7.x 3.x.y compatible print function
from __future__ import print_function
# import Logger
from pysimplelog import Logger

# initialize
l=Logger("log test")

# change log file basename from simplelog to mylog
l.set_log_file_basename("mylog")

# change log file extension from .log to .pylog
l.set_log_file_extension("pylog")

# Add new log types.
l.add_log_type("super critical", name="SUPER CRITICAL", level=200, color='red', attributes=["bold","underline"])
l.add_log_type("wrong", name="info", color='magenta', attributes=["strike through"])
l.add_log_type("important", name="info", color='black', highlight="orange", attributes=["bold"])

# update error log type
l.update_log_type(logType='error', color='pink', attributes=['underline','bold'])

# print logger
print(l, end="\n\n")

# test logging
l.info("I am info, called using my shortcut method.")
l.log("info", "I am  info, called using log method.")

l.warn("I am warn, called using my shortcut method.")
l.log("warn", "I am warn, called using log method.")

l.error("I am error, called using my shortcut method.")
l.log("error", "I am error, called using log method.")

l.critical("I am critical, called using my shortcut method.")
l.log("critical", "I am critical, called using log method.")

l.debug("I am debug, called using my shortcut method.")
l.log("debug", "I am debug, called using log method.")

l.log("super critical", "I am super critical, called using log method because I have no shortcut method.")
l.log("wrong", "I am wrong, called using log method because I have no shortcut method.")
l.log("important", "I am important, called using log method because I have no shortcut method.")

# print last logged messages
print("")
print("Last logged messages are:")
print("=========================")
print(l.lastLoggedMessage)
print(l.lastLoggedDebug)
print(l.lastLoggedInfo)
print(l.lastLoggedWarning)
print(l.lastLoggedError)
print(l.lastLoggedCritical)

# log data
print("")
print("Log random data and traceback stack:")
print("====================================")
l.info("Check out this data", data=list(range(10)))
print("")

# log error with traceback
import traceback
try:
    1/range(10)
except Exception as err:
    l.error('%s (is this python ?)'%err, tback=traceback.extract_stack())

output


    Logger (Version 4.0.0)
    log type       |log name       |level     |std flag  |file flag |
    ---------------|---------------|----------|----------|----------|
    wrong          |info           |0.0       |True      |True      |
    debug          |DEBUG          |0.0       |True      |True      |
    important      |info           |0.0       |True      |True      |
    info           |INFO           |10.0      |True      |True      |
    warn           |WARNING        |20.0      |True      |True      |
    error          |ERROR          |30.0      |True      |True      |
    critical       |CRITICAL       |100.0     |True      |True      |
    super critical |SUPER CRITICAL |200.0     |True      |True      |

    2018-09-07 16:07:58 - log test <INFO> I am info, called using my shortcut method.
    2018-09-07 16:07:58 - log test <INFO> I am  info, called using log method.
    2018-09-07 16:07:58 - log test <WARNING> I am warn, called using my shortcut method.
    2018-09-07 16:07:58 - log test <WARNING> I am warn, called using log method.
    2018-09-07 16:07:58 - log test <ERROR> I am error, called using my shortcut method.
    2018-09-07 16:07:58 - log test <ERROR> I am error, called using log method.
    2018-09-07 16:07:58 - log test <CRITICAL> I am critical, called using my shortcut method.
    2018-09-07 16:07:58 - log test <CRITICAL> I critical, called using log method.
    2018-09-07 16:07:58 - log test <DEBUG> I am debug, called using my shortcut method.
    2018-09-07 16:07:58 - log test <DEBUG> I am debug, called using log method.
    2018-09-07 16:07:58 - log test <SUPER CRITICAL> I am super critical, called using log method because I have no shortcut method.
    2018-09-07 16:07:58 - log test <info> I am wrong, called using log method because I have no shortcut method.
    2015-11-18 14:25:08 - log test <info> I am important, called using log method because I have no shortcut method.

    Last logged messages are:
    =========================
    I am important, called using log method because I have no shortcut method.
    I am debug, called using log method.
    I am  info, called using log method.
    I am warn, called using log method.
    I am error, called using log method.
    I am critical, called using log method.

    Log random data and traceback stack:
    ====================================
    2018-09-07 16:07:58 - log test  Check out this data
    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
    2015-11-18 14:25:08 - log test <ERROR> unsupported operand type(s) for /: 'int' and 'list' (is this python ?)
      File "<stdin>", line 4, in <module>
class pysimplelog.SimpleLog.Logger(name='logger', flush=True, logToStdout=True, stdout=None, logToFile=True, logFile=None, logFileBasename='simplelog', logFileExtension='log', logFileMaxSize=10, logFileFirstNumber=0, logFileRoll=None, stdoutMinLevel=None, stdoutMaxLevel=None, fileMinLevel=None, fileMaxLevel=None, logTypes=None, timezone=None, *args, **kwargs)

This is simplelog main Logger class definition.

A logging is constituted of a header a message and a footer. In the current implementation the footer is empty and the header is as the following:

date time - loggerName <logTypeName>

In order to change any of the header or the footer, ‘_get_header’ and ‘_get_footer’ methods must be overloaded.

When used in a python application, it is advisable to use Logger singleton implementation and not Logger itself. if no overloading is needed one can simply import the singleton as the following:

from pysimplelog import SingleLogger as Logger

A new Logger instanciates with the following logType list (logTypes <NAME>: level)

  • debug <DEBUG>: 0

  • info <INFO>: 10

  • warn <WARNING>: 20

  • error <ERROR>: 30

  • critical <CRITICAL>: 100

Recommended overloading implementation, this is how it could be done:

from pysimplelog import SingleLogger as LOG

class Logger(LOG):
    # *args and **kwargs can be replace by fixed arguments
    def custom_init(self, *args, **kwargs):
        # hereinafter any further instanciation can be coded

In case overloading __init__ is needed, this is how it could be done:

from pysimplelog import SingleLogger as LOG

class Logger(LOG):
    # custom_init will still be called in super(Logger, self).__init__(*args, **kwargs)
    def __init__(self, *args, **kwargs):
        if self._isInitialized: return
        super(Logger, self).__init__(*args, **kwargs)
        # hereinafter any further instanciation can be coded
Parameters

  1. name (string): The logger name.

  2. flush (boolean): Whether to always flush the logging streams.

  3. logToStdout (boolean): Whether to log to the standard output stream.

  4. stdout (None, stream): The standard output stream. If None, system standard output will be set automatically. Otherwise any stream with read and write methods can be passed

  5. logToFile (boolean): Whether to log to to file.

  6. logFile (None, string): the full log file path including directory basename and extension. If this is given, all of logFileBasename and logFileExtension will be discarded. logfile is equivalent to logFileBasename.logFileExtension

  7. logFileBasename (string): Logging file directory path and file basename. A logging file full name is set as logFileBasename.logFileExtension

  8. logFileExtension (string): Logging file extension. A logging file full name is set as logFileBasename.logFileExtension

  9. logFileMaxSize (None, number): The maximum size in Megabytes of a logging file. Once exceeded, another logging file as logFileBasename_N.logFileExtension will be created. Where N is an automatically incremented number. If None or a negative number is given, the logging file will grow indefinitely

  10. logFileFirstNumber (None, integer): first log file number ‘N’ in logFileBasename_N.logFileExtension. If None is given then first log file will be logFileBasename.logFileExtension and ince logFileMaxSize is reached second log file will be logFileBasename_0.logFileExtension and so on and so forth. If number is given it must be an integer >=0

  11. logFileRoll (None, intger): If given, it sets the maximum number of log files to write. Exceeding the number will result in deleting previous ones. This also insures always increasing files numbering.

  12. stdoutMinLevel(None, number): The minimum logging to system standard output level. If None, standard output minimum level checking is left out.

  13. stdoutMaxLevel(None, number): The maximum logging to system standard output level. If None, standard output maximum level checking is left out.

  14. fileMinLevel(None, number): The minimum logging to file level. If None, file minimum level checking is left out.

  15. fileMaxLevel(None, number): The maximum logging to file level. If None, file maximum level checking is left out.

  16. logTypes (None, dict): Used to create and update existing log types upon initialization. Given dictionary keys are logType (new or existing) and values can be None or a dictionary of kwargs to call update_log_type upon. This argument will be called after custom_init

  17. timezone (None, str): Logging time timezone. If provided pytz must be installed and it must be the timezone name. If not provided, the machine default timezone will be used.

  18. *args: This is used to send non-keyworded variable length argument

    list to custom initialize. args will be parsed and used in custom_init method.

  19. **kwargs: This allows passing keyworded variable length of

    arguments to custom_init method. kwargs can be anything other than __init__ arguments.

property lastLogged

Get a dictionary of last logged messages. Keys are log types and values are the the last messages.

property lastLoggedMessage

Get last logged message of any type. Retuns None if no message was logged.

property lastLoggedDebug

Get last logged message of type ‘debug’. Retuns None if no message was logged.

property lastLoggedInfo

Get last logged message of type ‘info’. Retuns None if no message was logged.

property lastLoggedWarning

Get last logged message of type ‘warn’. Retuns None if no message was logged.

property lastLoggedError

Get last logged message of type ‘error’. Retuns None if no message was logged.

property lastLoggedCritical

Get last logged message of type ‘critical’. Retuns None if no message was logged.

property logTypes

list of all defined log types.

property logLevels

dictionary copy of all defined log types levels.

property logTypeFileFlags

dictionary copy of all defined log types logging to a file flags.

property logTypeStdoutFlags

dictionary copy of all defined log types logging to Standard output flags.

property stdoutMinLevel

Standard output minimum logging level.

property stdoutMaxLevel

Standard output maximum logging level.

property fileMinLevel

file logging minimum level.

property fileMaxLevel

file logging maximum level.

property forcedStdoutLevels

dictionary copy of forced flags of logging to standard output.

property forcedFileLevels

dictionary copy of forced flags of logging to file.

property logTypeNames

dictionary copy of all defined log types logging names.

property logTypeLevels

dictionary copy of all defined log types levels showing when logging.

property logTypeFormats

dictionary copy of all defined log types format showing when logging.

property name

logger name.

property logToStdout

log to stdout flag.

property logFileRoll

Log file roll parameter.

property logToFile

log to file flag.

property logFileName

currently used log file name.

property logFileBasename

log file basename.

property logFileExtension

log file extension.

property logFileMaxSize

maximum allowed logfile size in megabytes.

property logFileFirstNumber

log file first number

property timezone

The timezone if given

set_timezone(timezone)

Set logging timezone

Parameters

  1. timezone (None, str): Logging time timezone. If provided pytz must be installed and it must be the timezone name. If not provided, the machine default timezone will be used

is_logType(logType)

Get whether given logType is defined or not

Parameters

  1. logType (string): A defined logging type.

Result

  1. result (boolean): Whether given logType is defined or not

update(**kwargs)

Update logger general parameters using key value pairs. Updatable parameters are name, flush, stdout, logToStdout, logFileRoll, logToFile, logFileMaxSize, stdoutMinLevel, stdoutMaxLevel, fileMinLevel, fileMaxLevel and logFileFirstNumber.

property parameters

get a dictionary of logger general parameters. The same dictionary can be used to update another logger instance using update method

custom_init(*args, **kwargs)

Custom initialize abstract method. This method will be called at the end of initialzation. This method needs to be overloaded to custom initialize Logger instances.

Parameters

  1. *args (): This is used to send non-keyworded variable length argument list to custom initialize.

  2. **kwargs (): This is keyworded variable length of arguments. kwargs can be anything other than __init__ arguments.

set_name(name)

Set the logger name.

Parameters

  1. name (string): The logger name.

set_flush(flush)

Set the logger flush flag.

Parameters

  1. flush (boolean): Whether to always flush the logging streams.

set_stdout(stream=None)

Set the logger standard output stream.

Parameters

  1. stdout (None, stream): The standard output stream. If None, system standard output will be set automatically. Otherwise any stream with read and write methods can be passed

set_log_to_stdout_flag(logToStdout)

Set the logging to the defined standard output flag. When set to False, no logging to standard output will happen regardless of a logType standard output flag.

Parameters

  1. logToStdout (boolean): Whether to log to the standard output stream.

set_log_to_file_flag(logToFile)

Set the logging to a file general flag. When set to False, no logging to file will happen regardless of a logType file flag.

Parameters

  1. logToFile (boolean): Whether to log to to file.

set_log_type_flags(logType, stdoutFlag, fileFlag)

Set a defined log type flags.

Parameters

  1. logType (string): A defined logging type.

  2. stdoutFlag (boolean): Whether to log to the standard output stream.

  3. fileFlag (boolean): Whether to log to to file.

set_log_file_roll(logFileRoll)

Set roll parameter to determine the maximum number of log files allowed. Beyond the maximum, older will be removed.

Parameters

  1. logFileRoll (None, intger): If given, it sets the maximum number of log files to write. Exceeding the number will result in deleting older files. This also insures always increasing files numbering. Log files will be identified in increasing N order of logFileBasename_N.logFileExtension pattern. Be careful setting this parameter as old log files will be permanently deleted if the number of files exceeds the value of logFileRoll

set_log_file(logfile)

Set the log file full path including directory path basename and extension.

Parameters

  1. logFile (string): the full log file path including basename and extension. If this is given, all of logFileBasename and logFileExtension will be discarded. logfile is equivalent to logFileBasename.logFileExtension

set_log_file_extension(logFileExtension)

Set the log file extension.

Parameters

  1. logFileExtension (string): Logging file extension. A logging file full name is set as logFileBasename.logFileExtension

set_log_file_basename(logFileBasename)

Set the log file basename.

Parameters

  1. logFileBasename (string): Logging file directory path and file basename. A logging file full name is set as logFileBasename.logFileExtension

set_log_file_maximum_size(logFileMaxSize)

Set the log file maximum size in megabytes

Parameters

  1. logFileMaxSize (None, number): The maximum size in Megabytes of a logging file. Once exceeded, another logging file as logFileBasename_N.logFileExtension will be created. Where N is an automatically incremented number. If None or a negative number is given, the logging file will grow indefinitely

set_log_file_first_number(logFileFirstNumber)

Set log file first number

Parameters

  1. logFileFirstNumber (None, integer): first log file number ‘N’ in logFileBasename_N.logFileExtension. If None is given then first log file will be logFileBasename.logFileExtension and ince logFileMaxSize is reached second log file will be logFileBasename_0.logFileExtension and so on and so forth. If number is given it must be an integer >=0

set_minimum_level(level=0, stdoutFlag=True, fileFlag=True)

Set the minimum logging level. All levels below the minimum will be ignored at logging.

Parameters

  1. level (None, number, str): The minimum level of logging. If None, minimum level checking is left out. If str, it must be a defined logtype and therefore the minimum level would be the level of this logtype.

  2. stdoutFlag (boolean): Whether to apply this minimum level to standard output logging.

  3. fileFlag (boolean): Whether to apply this minimum level to file logging.

set_maximum_level(level=0, stdoutFlag=True, fileFlag=True)

Set the maximum logging level. All levels above the maximum will be ignored at logging.

Parameters

  1. level (None, number, str): The maximum level of logging. If None, maximum level checking is left out. If str, it must be a defined logtype and therefore the maximum level would be the level of this logtype.

  2. stdoutFlag (boolean): Whether to apply this maximum level to standard output logging.

  3. fileFlag (boolean): Whether to apply this maximum level to file logging.

force_log_type_stdout_flag(logType, flag)

Force a logtype standard output logging flag despite minimum and maximum logging level boundaries.

Parameters

  1. logType (string): A defined logging type.

  2. flag (None boolean): The standard output logging flag. If None, logtype existing forced flag is released.

force_log_type_file_flag(logType, flag)

Force a logtype file logging flag despite minimum and maximum logging level boundaries.

Parameters

  1. logType (string): A defined logging type.

  2. flag (None, boolean): The file logging flag. If None, logtype existing forced flag is released.

force_log_type_flags(logType, stdoutFlag, fileFlag)

Force a logtype logging flags.

Parameters

  1. logType (string): A defined logging type.

  2. stdoutFlag (None, boolean): The standard output logging flag. If None, logtype stdoutFlag forcing is released.

  3. fileFlag (None, boolean): The file logging flag. If None, logtype fileFlag forcing is released.

set_log_type_name(logType, name)

Set a logtype name.

Parameters

  1. logType (string): A defined logging type.

  2. name (string): The logtype new name.

set_log_type_level(logType, level)

Set a logtype logging level.

Parameters

  1. logType (string): A defined logging type.

  2. level (number): The level of logging.

remove_log_type(logType, _assert=False)

Remove a logtype.

Parameters

  1. logType (string): The logtype.

  2. _assert (boolean): Raise an assertion error if logType is not defined.

add_log_type(logType, name=None, level=0, stdoutFlag=None, fileFlag=None, color=None, highlight=None, attributes=None)

Add a new logtype.

Parameters

  1. logType (string): The logtype.

  2. name (None, string): The logtype name. If None, name will be set to logtype.

  3. level (number): The level of logging.

  4. stdoutFlag (None, boolean): Force standard output logging flag. If None, flag will be set according to minimum and maximum levels.

  5. fileFlag (None, boolean): Force file logging flag. If None, flag will be set according to minimum and maximum levels.

  6. color (None, string): The logging text color. The defined colors are:

    black , red , green , orange , blue , magenta , cyan , grey , dark grey , light red , light green , yellow , light blue , pink , light cyan

  7. highlight (None, string): The logging text highlight color. The defined highlights are:

    black , red , green , orange , blue , magenta , cyan , grey

  8. attributes (None, string): The logging text attribute. The defined attributes are:

    bold , underline , blink , invisible , strike through

N.B logging color, highlight and attributes are not allowed on all types of streams.

update_log_type(logType, name=None, level=None, stdoutFlag=None, fileFlag=None, color=None, highlight=None, attributes=None)

update a logtype.

Parameters

  1. logType (string): The logtype.

  2. name (None, string): The logtype name. If None, name will be set to logtype.

  3. level (number): The level of logging.

  4. stdoutFlag (None, boolean): Force standard output logging flag. If None, flag will be set according to minimum and maximum levels.

  5. fileFlag (None, boolean): Force file logging flag. If None, flag will be set according to minimum and maximum levels.

  6. color (None, string): The logging text color. The defined colors are:

    black , red , green , orange , blue , magenta , cyan , grey , dark grey , light red , light green , yellow , light blue , pink , light cyan

  7. highlight (None, string): The logging text highlight color. The defined highlights are:

    black , red , green , orange , blue , magenta , cyan , grey

  8. attributes (None, string): The logging text attribute. The defined attributes are:

    bold , underline , blink , invisible , strike through

N.B logging color, highlight and attributes are not allowed on all types of streams.

is_enabled_for_stdout(logType)

Get whether given logtype is enabled for standard output logging. When a logType is not enabled, calling for log will return without logging. This method will check general standard output logging flag and given logType standard output flag. For a logType to log it must have both flags set to True

Parameters

  1. logType (string): A defined logging type.

Returns

  1. enabled (bool): whehter enabled or not.

is_enabled_for_file(logType)

Get whether given logtype is enabled for file logging. When a logType is not enabled, calling for log will return without logging. This method will check general file logging flag and given logType file flag. For a logType to log it must have both flags set to True

Parameters

  1. logType (string): A defined logging type.

Returns

  1. enabled (bool): whehter enabled or not.

log(logType, message, data=None, tback=None)

log a message of a certain logtype.

Parameters

  1. logType (string): A defined logging type.

  2. message (string): Any message to log.

  3. data (None, object): Any type of data to print and/or write to log file after log message

  4. tback (None, str, list): Stack traceback to print and/or write to log file. In general, this should be traceback.extract_stack

Returns

  1. message (string): the logged message

force_log(logType, message, data=None, tback=None, stdout=True, file=True)

Force logging a message of a certain logtype whether logtype level is allowed or not.

Parameters

  1. logType (string): A defined logging type.

  2. message (string): Any message to log.

  3. tback (None, str, list): Stack traceback to print and/or write to log file. In general, this should be traceback.extract_stack

  4. stdout (boolean): Whether to force logging to standard output.

  5. file (boolean): Whether to force logging to file.

Returns

  1. message (string): the logged message

flush()

Flush all streams.

info(message, *args, **kwargs)

alias to message at information level

information(message, *args, **kwargs)

alias to message at information level

warn(message, *args, **kwargs)

alias to message at warning level

warning(message, *args, **kwargs)

alias to message at warning level

error(message, *args, **kwargs)

alias to message at error level

critical(message, *args, **kwargs)

alias to message at critical level

debug(message, *args, **kwargs)

alias to message at debug level

class pysimplelog.SimpleLog.SingleLogger(*args, **kwargs)

This is singleton implementation of Logger class.