ameliabot/core/logger.py

135 lines
4.0 KiB
Python

"""
colargulog
Python3 Logging with Colored Arguments and new string formatting style
Written by david.ohana@ibm.com
License: Apache-2.0
"""
import logging
import logging.handlers
import re
class ColorCodes:
grey = "\x1b[38;21m"
green = "\x1b[1;32m"
yellow = "\x1b[33;21m"
red = "\x1b[31;21m"
bold_red = "\x1b[31;1m"
blue = "\x1b[1;34m"
light_blue = "\x1b[1;36m"
purple = "\x1b[1;35m"
reset = "\x1b[0m"
class ColorizedArgsFormatter(logging.Formatter):
arg_colors = [ColorCodes.purple, ColorCodes.light_blue]
level_fields = ["levelname", "levelno"]
level_to_color = {
logging.DEBUG: ColorCodes.grey,
logging.INFO: ColorCodes.green,
logging.WARNING: ColorCodes.yellow,
logging.ERROR: ColorCodes.red,
logging.CRITICAL: ColorCodes.bold_red,
}
def __init__(self, fmt: str):
super().__init__()
self.level_to_formatter = {}
def add_color_format(level: int):
color = ColorizedArgsFormatter.level_to_color[level]
_format = fmt
for fld in ColorizedArgsFormatter.level_fields:
search = r"(%\(" + fld + r"\).*?s)"
_format = re.sub(search, f"{color}\\1{ColorCodes.reset}", _format) # NOQA
formatter = logging.Formatter(_format)
self.level_to_formatter[level] = formatter
add_color_format(logging.DEBUG)
add_color_format(logging.INFO)
add_color_format(logging.WARNING)
add_color_format(logging.ERROR)
add_color_format(logging.CRITICAL)
@staticmethod
def rewrite_record(record: logging.LogRecord):
if not BraceFormatStyleFormatter.is_brace_format_style(record):
return
msg = record.msg
msg = msg.replace("{", "_{{")
msg = msg.replace("}", "_}}")
placeholder_count = 0
# add ANSI escape code for next alternating
# color before each formatting parameter
# and reset color after it.
while True:
if "_{{" not in msg:
break
color_index = placeholder_count % len(ColorizedArgsFormatter.arg_colors) # NOQA
color = ColorizedArgsFormatter.arg_colors[color_index]
msg = msg.replace("_{{", color + "{", 1)
msg = msg.replace("_}}", "}" + ColorCodes.reset, 1)
placeholder_count += 1
record.msg = msg.format(*record.args)
record.args = []
def format(self, record):
orig_msg = record.msg
orig_args = record.args
formatter = self.level_to_formatter.get(record.levelno)
self.rewrite_record(record)
formatted = formatter.format(record)
# restore log record to original state for other handlers
record.msg = orig_msg
record.args = orig_args
return formatted
class BraceFormatStyleFormatter(logging.Formatter):
def __init__(self, fmt: str):
super().__init__()
self.formatter = logging.Formatter(fmt)
@staticmethod
def is_brace_format_style(record: logging.LogRecord):
if len(record.args) == 0:
return False
msg = record.msg
if '%' in msg:
return False
count_of_start_param = msg.count("{")
count_of_end_param = msg.count("}")
if count_of_start_param != count_of_end_param:
return False
if count_of_start_param != len(record.args):
return False
return True
@staticmethod
def rewrite_record(record: logging.LogRecord):
if not BraceFormatStyleFormatter.is_brace_format_style(record):
return
record.msg = record.msg.format(*record.args)
record.args = []
def format(self, record):
orig_msg = record.msg
orig_args = record.args
self.rewrite_record(record)
formatted = self.formatter.format(record)
# restore log record to original state for other handlers
record.msg = orig_msg
record.args = orig_args
return formatted