ENH: Change logging level colours

src/triumvirate/logger.py

@@ -9,15 +9,27 @@
 
 """  # numpydoc ignore=SS01
 import logging
+import os
 import sys
 import time
 import warnings
+from copy import copy
 
 
-class _ElapsedLogFormatter(logging.Formatter):
-    """Elapsed-time logging formatter.
+class _ElapsedColourLogFormatter(logging.Formatter):
+    """Elapsed-time colourised logging formatter.
 
     """
+    # Log level colours
+    _IN_BOLD = 1  # default to: 0 for non-bold, 1 for bold
+    _COLOURS = {
+        'NOTSET': "\033[0m",                    # reset
+        'DEBUG': f"\033[{_IN_BOLD};36m",        # cyan
+        'INFO': f"\033[{_IN_BOLD};32m",         # green (blue)
+        'WARNING': f"\033[{_IN_BOLD};33m",      # yellow
+        'ERROR': f"\033[{_IN_BOLD};31m",        # red
+        'CRITICAL': f"\033[{_IN_BOLD};37;41m",  # white on red
+    }
 
     _start_time = time.time()
 
@@ -36,13 +48,25 @@ def format(self, record):
             Modified log record with elapsed time.
 
         """
+        fmt_record = copy(record)
+
         elapsed_time = record.created - self._start_time
         h, remainder_time = divmod(elapsed_time, 3600)
         m, s = divmod(remainder_time, 60)
 
-        record.elapsed = f"(+{int(h):02d}:{int(m):02d}:{int(s):02d})"
+        fmt_record.elapsed = f"(+{int(h):02d}:{int(m):02d}:{int(s):02d})"
+
+        reset = self._COLOURS.get('NOTSET', "\033[0m")
+        colour = self._COLOURS.get(record.levelname, reset)
+
+        fmt_record.levelname = f"{record.levelname:.4s}"\
+            .replace('DEBU', 'DBUG')\
+            .replace('CRIT', 'FATAL')
+        if 'color' in os.getenv('TERM', '') \
+                and os.getenv('TRV_INTERACTIVE') is not None:
+            fmt_record.levelname = colour + fmt_record.levelname + reset
 
-        return logging.Formatter.format(self, record)
+        return logging.Formatter.format(self, fmt_record)
 
 
 class _CppLogAdapter(logging.LoggerAdapter):
@@ -138,8 +162,8 @@ def setup_logger(log_level=logging.INFO):
 
     """
     # Set formatter.
-    formatter = _ElapsedLogFormatter(
-        fmt='[%(asctime)s %(elapsed)s %(levelname).4s] %(message)s',
+    formatter = _ElapsedColourLogFormatter(
+        fmt='[%(asctime)s %(elapsed)s %(levelname)s] %(message)s',
         datefmt='%Y-%m-%d %H:%M:%S'
     )
 

src/triumvirate/src/monitor.cpp

@@ -149,7 +149,7 @@ std::string show_timestamp() {
 
 void exit_fatal(const std::string& msg) {
   if (is_colourable()) {
-    std::cout << "\n\033[1;31mFATAL:\033[0m " << msg << std::endl;
+    std::cout << "\n\033[1;37;41mFATAL:\033[0m " << msg << std::endl;
   } else {
     std::cout << "\nFATAL: " << msg << std::endl;
   }
@@ -212,7 +212,7 @@ void Logger::log(int level_entry, const char* fmt_string, ...) {
           log_type = "";
           break;
         case LogLevel::DBUG:
-          log_type = "\033[0;35mDBUG\033[0m";  // magenta
+          log_type = "\033[0;36mDBUG\033[0m";  // cyan
           break;
         case LogLevel::STAT:
           log_type = "\033[0;34mSTAT\033[0m";  // blue
@@ -267,7 +267,7 @@ void Logger::debug(const char* fmt_string, ...) {
     std::va_list args;
     va_start(args, fmt_string);
     if (is_colourable()) {
-      Logger::emit("\033[0;35mDBUG\033[0m", fmt_string, args);
+      Logger::emit("\033[0;36mDBUG\033[0m", fmt_string, args);
     } else {
       Logger::emit("DBUG", fmt_string, args);
     }

tests/test_logger.py

@@ -9,8 +9,14 @@
 
 # Define the RegEx expression for logging format.
 _LOG_FORMAT = (
-    r"\[\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2}\s\(\+\d+:\d{2}:\d{2}\)\s\w{4}\]"
-    r"\s.*\(in C\+\+\)"
+    r"\["                                                     # [
+    r"\d{4}-\d{2}-\d{2}\s"                                    # date
+    r"\d{2}:\d{2}:\d{2}\s"                                    # timestamp
+    r"\(\+\d+:\d{2}:\d{2}\)\s"                                # elapsed time
+    r"(?:\033\[\d+(?:;\d+)*m)?\w{4}(?:\033\[\d+(?:;\d+)*m)?"  # log level
+    r"\]\s"                                                   # ]
+    r".*"                                                     # log message
+    r"\(in C\+\+\)"                                           # C++ indication
 )