Add colored logs

requirements/main.txt

@@ -2,6 +2,7 @@
 # setup.py lists a separate set of requirements that are looser to simplify
 # installation
 cffi == 1.14.0
+coloredlogs == 14.0  # technically optional
 img2pdf == 0.3.3
 pdfminer.six == 20200124
 pikepdf == 1.10.2

setup.py

@@ -97,6 +97,7 @@ setup(
     install_requires=[
         'chardet >= 3.0.4, < 4',  # unlisted requirement of pdfminer.six 20181108
         'cffi >= 1.9.1',  # must be a setup and install requirement
+        'coloredlogs >= 14.0',  # strictly optional
         'img2pdf >= 0.3.0, < 0.4',  # pure Python, so track HEAD closely
         'pdfminer.six >= 20181108, <= 20200124',
         'pikepdf >= 1.8.1, < 2',

src/ocrmypdf/api.py

@@ -28,6 +28,11 @@ from ._sync import run_pipeline
 from ._validation import check_options
 from .cli import parser
 
+try:
+    import coloredlogs
+except ModuleNotFoundError:
+    coloredlogs = None
+
 
 class Verbosity(IntEnum):
     """Verbosity level for configure_logging."""
@@ -92,7 +97,18 @@ def configure_logging(
     else:
         fmt = '%(levelname)7s -%(pageno)s %(message)s'
 
-    formatter = logging.Formatter(fmt=fmt)
+    use_colors = progress_bar_friendly
+    if not coloredlogs:
+        use_colors = False
+    if use_colors:
+        if os.name == 'nt':
+            use_colors = coloredlogs.enable_ansi_support()
+        if use_colors:
+            use_colors = coloredlogs.terminal_supports_colors()
+    if use_colors:
+        formatter = coloredlogs.ColoredFormatter(fmt=fmt)
+    else:
+        formatter = logging.Formatter(fmt=fmt)
 
     console.setFormatter(formatter)
     log.addHandler(console)