core: some tweaks for better colour handling when we're redirecting stdout/stderr

my/core/logging.py

@@ -128,10 +128,12 @@ def setup_logger(logger: str | logging.Logger, *, level: LevelIsh = None) -> Non
     else:
         # log_color/reset are specific to colorlog
         FORMAT_COLOR = FORMAT.format(start='%(log_color)s', end='%(reset)s')
-        fmt = FORMAT_COLOR if ch.stream.isatty() else FORMAT_NOCOLOR
         # colorlog should detect tty in principle, but doesn't handle everything for some reason
         # see https://github.com/borntyping/python-colorlog/issues/71
-        formatter = colorlog.ColoredFormatter(fmt)
+        if ch.stream.isatty():
+            formatter = colorlog.ColoredFormatter(FORMAT_COLOR)
+        else:
+            formatter = logging.Formatter(FORMAT_NOCOLOR)
 
     ch.setFormatter(formatter)
 

my/core/preinit.py

@@ -1,5 +1,8 @@
 from pathlib import Path
 
+# todo preinit isn't really a good name? it's only in a separate file because
+# - it's imported from my.core.init (so we wan't to keep this file as small/reliable as possible, hence not common or something)
+# - we still need this function in __main__, so has to be separate from my/core/init.py
 def get_mycfg_dir() -> Path:
     import appdirs
     import os

my/core/warnings.py

@@ -16,7 +16,7 @@ def _colorize(x: str, color: Optional[str]=None) -> str:
     if color is None:
         return x
 
-    if not sys.stdout.isatty():
+    if not sys.stderr.isatty():
         return x
     # click handles importing/initializing colorama if necessary
     # on windows it installs it if necessary