Added stripped down TerminalWriter from py library which only support…

…s coloring. Refs devpi#930

common/devpi_common/terminal.py

@@ -0,0 +1,62 @@
+try:
+    import colorama
+except ImportError:
+    colorama = None
+import os
+import sys
+
+
+_esctable = dict(
+    bold='\x1b[1m', light='\x1b[2m', blink='\x1b[5m', invert='\x1b[7m',
+    black='\x1b[30m', red='\x1b[31m', green='\x1b[32m', yellow='\x1b[33m',
+    blue='\x1b[34m', purple='\x1b[35m', cyan='\x1b[36m', white='\x1b[37m',
+    Black='\x1b[40m', Red='\x1b[41m', Green='\x1b[42m', Yellow='\x1b[43m',
+    Blue='\x1b[44m', Purple='\x1b[45m', Cyan='\x1b[46m', White='\x1b[47m')
+
+
+def isatty(fd):
+    return hasattr(fd, 'isatty') and fd.isatty()
+
+
+def should_do_markup(fd):
+    if os.environ.get('PY_COLORS') == '1':
+        return True
+    if os.environ.get('PY_COLORS') == '0':
+        return False
+    if 'NO_COLOR' in os.environ:
+        return False
+    if os.environ.get('TERM') == 'dumb':
+        return False
+    if sys.platform.startswith('java') and os._name == 'nt':
+        return False
+    return isatty(fd)
+
+
+class TerminalWriter:
+    def __init__(self, fd=None):
+        if fd is None:
+            fd = sys.stdout
+        if colorama is not None and isatty(fd):
+            fd = colorama.AnsiToWin32(fd).stream
+        self.fd = fd
+        self.hasmarkup = should_do_markup(fd)
+
+    def markup(self, text, **kwargs):
+        esc = []
+        for name in kwargs:
+            if name not in _esctable:
+                raise ValueError(f"unknown markup: {name!r}")
+            if kwargs[name]:
+                esc.append(_esctable[name])
+        return ''.join((*esc, text, '\x1b[0m'))
+
+    def write(self, msg, **kwargs):
+        if not msg:
+            return
+        if self.hasmarkup and kwargs:
+            msg = self.markup(msg, **kwargs)
+        self.fd.write(msg)
+
+    def line(self, s='', **kwargs):
+        self.write(s, **kwargs)
+        self.write('\n')

common/news/930.feature

@@ -0,0 +1 @@
+Added stripped down TerminalWriter from ``py`` library which only supports coloring.