Refactor console_utilities

- Use `re.Pattern`
- Avoid importing `shutil` for speed

Author: AA-Turner

sphinx/_cli/console_utilities.py

@@ -2,9 +2,8 @@
 
 import os
 import re
-import shutil
 import sys
-from typing import Dict, Pattern
+from typing import Dict
 
 try:
     # check if colorama is installed to support color on Windows
@@ -13,7 +12,7 @@
     colorama = None
 
 
-_ansi_re: Pattern = re.compile('\x1b\\[(\\d\\d;){0,2}\\d\\dm')
+_ansi_re: 're.Pattern[str]' = re.compile('\x1b\\[(\\d\\d;){0,2}\\d\\dm')
 codes: Dict[str, str] = {}
 
 
@@ -24,7 +23,17 @@ def terminal_safe(s: str) -> str:
 
 def get_terminal_width() -> int:
     """Return the width of the terminal in columns."""
-    return shutil.get_terminal_size().columns - 1
+    try:
+        columns = int(os.environ.get('COLUMNS', 0))
+    except ValueError:
+        columns = 0
+    if columns > 1:
+        return columns - 1
+    try:
+        return os.get_terminal_size(sys.__stdout__.fileno()).columns - 1
+    except (AttributeError, ValueError, OSError):
+        # fallback
+        return 80 - 1
 
 
 _tw: int = get_terminal_width()