Support colorscheme with only basic ANSI color sequences

stackprinter/__init__.py

@@ -82,6 +82,9 @@ def format(thing=None, **kwargs):
     style: string
         'plaintext' (default): Output just text
 
+        'ansi': Enable colors, using basic ansi sequences. It is compatible
+            with light and dark background, based on terminal settings.
+
         'darkbg', 'darkbg2', 'darkbg3', 'lightbg', 'lightbg2', 'lightbg3':
             Enable colors, for use in terminals that support 256 ansi
             colors or in jupyter notebooks (or even with `ansi2html`)

stackprinter/colorschemes.py

@@ -1,19 +1,92 @@
 import random
+import colorsys
 
 
-__all__ = ['color', 'darkbg', 'darkbg2', 'darkbg3',
+__all__ = ['plaintext', 'color',
+           'darkbg', 'darkbg2', 'darkbg3',
            'lightbg', 'lightbg2', 'lightbg3']
 
 class ColorScheme():
 
     def __getitem__(self, name):
         raise NotImplemented
 
-    def get_random(self):
+    def get_random(self, seed, highlight):
+        raise NotImplemented
+
+
+class plaintext(ColorScheme):
+
+    def __getitem__(self, name):
+        return "%s"
+
+    def get_random(self, seed, highlight):
+        return "%s"
+
+
+class ansi(ColorScheme):
+    colors = {
+        'exception_type': '31',
+        'exception_msg': '31',
+        'highlight': '1;31',
+        'header': '0',
+        'lineno': '1',
+        'arrow_lineno': '1',
+        'dots': '0',
+        'source_bold': '0',
+        'source_default': '0',
+        'source_comment': '0',
+        'var_invisible': '0',
+    }
+
+    def __init__(self):
+        self.rng = random.Random()
+
+    def __getitem__(self, name):
+        return self._ansi_tpl(self.colors[name])
+
+    def get_random(self, seed, highlight):
+        self.rng.seed(seed)
+        random_code = str(self.rng.randint(32, 36))
+        if self.rng.choice((True, False)):
+            random_code = "1;" + random_code
+        return self._ansi_tpl(random_code)
+
+    @staticmethod
+    def _ansi_tpl(color_code):
+        return f"\u001b[{color_code}m%s\u001b[0m"
+
+
+class HslScheme(ColorScheme):
+    colors = {}
+
+    def __init__(self):
+        self.rng = random.Random()
+
+    def __getitem__(self, name):
+        return self._ansi_tpl(*self.colors[name])
+
+    def get_random(self, seed, highlight):
+        self.rng.seed(seed)
+        return self._ansi_tpl(*self._random_color(highlight))
+
+    def _random_color(self, highlight):
         raise NotImplemented
 
+    @staticmethod
+    def _ansi_tpl(hue, sat, val, bold=False):
+        r_, g_, b_ = colorsys.hsv_to_rgb(hue, sat, val)
+        r = int(round(r_*5))
+        g = int(round(g_*5))
+        b = int(round(b_*5))
+        point = 16 + 36 * r + 6 * g + b
+
+        bold_tp = '1;' if bold else ''
+        code_tpl = ('\u001b[%s38;5;%dm' % (bold_tp, point)) + '%s\u001b[0m'
+        return code_tpl
+
 
-class darkbg(ColorScheme):
+class darkbg(HslScheme):
                               # Hue, Sat, Val, Bold
     colors = {'exception_type': (0.0, 0.9, 0.6, False),
               'exception_msg':  (0.0, 0.9, 0.6, True),
@@ -31,27 +104,17 @@ class darkbg(ColorScheme):
               'var_invisible':  (0.6, 0.4, 0.4, False)
              }
 
-    def __init__(self):
-        self.rng = random.Random()
-
-    def __getitem__(self, name):
-        return self.colors[name]
-
-    def get_random(self, seed, highlight):
-        self.rng.seed(seed)
-
+    def _random_color(self, highlight):
         hue = self.rng.uniform(0.05,0.7)
-        # if hue < 0:
-        #     hue = hue + 1
-        sat = 1. #1. if highlight else 0.5
-        val = 0.5 #1. if highlight else 0.3
+        sat = 1.0
+        val = 0.5
         bold = highlight
 
         return hue, sat, val, bold
 
 
 
-class darkbg2(ColorScheme):
+class darkbg2(HslScheme):
                               # Hue, Sat, Val, Bold
     colors = {'exception_type': (0., 1., 0.8, True),
               'exception_msg':  (0., 1., 0.8, True),
@@ -69,26 +132,16 @@ class darkbg2(ColorScheme):
               'var_invisible':  (0.6, 0.4, 0.4, False)
              }
 
-    def __init__(self):
-        self.rng = random.Random()
-
-    def __getitem__(self, name):
-        return self.colors[name]
-
-    def get_random(self, seed, highlight):
-        self.rng.seed(seed)
-
+    def _random_color(self, highlight):
         hue = self.rng.uniform(0.05,0.7)
-        # if hue < 0:
-        #     hue = hue + 1
-        sat = 1. if highlight else 1.
-        val = 0.8 #if highlight else 0.5
+        sat = 1.0
+        val = 0.8
         bold = highlight
 
         return hue, sat, val, bold
 
 
-class darkbg3(ColorScheme):
+class darkbg3(HslScheme):
                               # Hue, Sat, Val, Bold
     colors = {'exception_type': (0., 1., 0.8, True),
               'exception_msg':  (0., 1., 0.8, True),
@@ -103,26 +156,16 @@ class darkbg3(ColorScheme):
               'var_invisible':  (0.6, 0.4, 0.4, False)
              }
 
-    def __init__(self):
-        self.rng = random.Random()
-
-    def __getitem__(self, name):
-        return self.colors[name]
-
-    def get_random(self, seed, highlight):
-        self.rng.seed(seed)
-
+    def _random_color(self, highlight):
         hue = self.rng.uniform(0.05,0.7)
-        # if hue < 0:
-        #     hue = hue + 1
-        sat = 1. if highlight else 1.
+        sat = 1.0
         val = 0.8 if highlight else 0.5
         bold = highlight
 
         return hue, sat, val, bold
 
 
-class lightbg(ColorScheme):
+class lightbg(HslScheme):
                               # Hue, Sat, Val, Bold
     colors = {'exception_type': (0.0, 1., 0.6, False),
               'exception_msg':  (0.0, 1., 0.6, True),
@@ -139,26 +182,16 @@ class lightbg(ColorScheme):
               'var_invisible':  (0.6, 0.4, 0.2, False)
              }
 
-    def __init__(self):
-        self.rng = random.Random()
-
-    def __getitem__(self, name):
-        return self.colors[name]
-
-    def get_random(self, seed, highlight):
-        self.rng.seed(seed)
-
+    def _random_color(self, highlight):
         hue = self.rng.uniform(0.05, 0.7)
-        # if hue < 0:
-        #     hue = hue + 1
-        sat = 1.
-        val = 0.5 #0.5 #0.6 if highlight else 0.2
+        sat = 1.0
+        val = 0.5
         bold = highlight
 
         return hue, sat, val, bold
 
 
-class lightbg2(ColorScheme):
+class lightbg2(HslScheme):
                               # Hue, Sat, Val, Bold
     colors = {'exception_type': (0.0, 1., 0.6, False),
               'exception_msg':  (0.0, 1., 0.6, True),
@@ -176,25 +209,15 @@ class lightbg2(ColorScheme):
               'var_invisible':  (0.6, 0.4, 0.2, False)
              }
 
-    def __init__(self):
-        self.rng = random.Random()
-
-    def __getitem__(self, name):
-        return self.colors[name]
-
-    def get_random(self, seed, highlight):
-        self.rng.seed(seed)
-
+    def _random_color(self, highlight):
         hue = self.rng.uniform(0.05, 0.7)
-        # if hue < 0:
-        #     hue = hue + 1
-        sat = 1.
+        sat = 1.0
         val = 0.5
         bold = True
 
         return hue, sat, val, bold
 
-class lightbg3(ColorScheme):
+class lightbg3(HslScheme):
                               # Hue, Sat, Val, Bold
     colors = {'exception_type': (0.0, 1., 0.7, False),
               'exception_msg':  (0.0, 1., 0.7, True),
@@ -212,19 +235,9 @@ class lightbg3(ColorScheme):
               'var_invisible':  (0.6, 0.4, 0.2, False)
              }
 
-    def __init__(self):
-        self.rng = random.Random()
-
-    def __getitem__(self, name):
-        return self.colors[name]
-
-    def get_random(self, seed, highlight):
-        self.rng.seed(seed)
-
+    def _random_color(self, highlight):
         hue = self.rng.uniform(0.05, 0.7)
-        # if hue < 0:
-        #     hue = hue + 1
-        sat = 1.
+        sat = 1.0
         val = 0.5
         bold = True
 
@@ -236,15 +249,31 @@ def get_random(self, seed, highlight):
 
 
 if __name__ == '__main__':
+    scheme = darkbg3()
+    for attr in [
+        'exception_type',
+        'exception_msg',
+        'highlight',
+        'header',
+        'lineno',
+        'arrow_lineno',
+        'dots',
+        'source_bold',
+        'source_default',
+        'source_comment',
+        'var_invisible',
+    ]:
+        print(scheme[attr] % attr)
+    exit()
     import numpy as np
-    from utils import get_ansi_tpl
+    hsl_scheme = HslScheme()
 
     for hue in np.arange(0,1.05,0.05):
         print('\n\nhue %.2f\nsat' % hue)
         for sat in np.arange(0,1.05,0.05):
             print('%.2f  ' % sat, end='')
             for val in np.arange(0,1.05,0.05):
-                tpl = get_ansi_tpl(hue, sat, val)
+                tpl = hsl_scheme._ansi_tpl(hue, sat, val)
                 # number = " (%.1f %.1f %.1f)" % (hue, sat, val)
                 number = ' %.2f' % val
                 print(tpl % number, end='')

stackprinter/formatting.py

@@ -6,15 +6,12 @@
 
 import stackprinter.extraction as ex
 import stackprinter.colorschemes as colorschemes
-from stackprinter.utils import match, get_ansi_tpl
+from stackprinter.utils import match
 from stackprinter.frame_formatting import FrameFormatter, ColorfulFrameFormatter
 
 
 def get_formatter(style, **kwargs):
-    if style in ['plaintext', 'plain']:
-        return FrameFormatter(**kwargs)
-    else:
-        return ColorfulFrameFormatter(style, **kwargs)
+    return ColorfulFrameFormatter(style, **kwargs)
 
 
 def format_summary(frames, style='plaintext', source_lines=1, reverse=False,
@@ -155,12 +152,9 @@ def format_exc_info(etype, evalue, tb, style='plaintext', add_summary='auto',
                                    suppressed_vars=suppressed_vars,
                                    **kwargs)
 
-            if style == 'plaintext':
-                msg +=  chain_hint
-            else:
-                sc = getattr(colorschemes, style)
-                clr = get_ansi_tpl(*sc.colors['exception_type'])
-                msg += clr % chain_hint
+            sc = getattr(colorschemes, style)()
+            clr = sc['exception_type']
+            msg += clr % chain_hint
 
         # Now, actually do some formatting:
         parts = []
@@ -226,15 +220,12 @@ def format_exception_message(etype, evalue, tb=None, style='plaintext'):
     if val_str:
         type_str += ": "
 
-    if style == 'plaintext':
-        return type_str + val_str
-    else:
-        sc = getattr(colorschemes, style)
+    sc = getattr(colorschemes, style)()
 
-        clr_head = get_ansi_tpl(*sc.colors['exception_type'])
-        clr_msg = get_ansi_tpl(*sc.colors['exception_msg'])
+    clr_head = sc['exception_type']
+    clr_msg = sc['exception_msg']
 
-        return clr_head % type_str + clr_msg % val_str
+    return clr_head % type_str + clr_msg % val_str
 
 
 def _walk_traceback(tb):