cmd2.Cmd.__init__ now initializes colorama and tells it to never strip ANSI codes since cmd2 deals with that

Also:
- Finished editing poutput(), ppaged(), and pfeedback() methods to strip ANSI color when appropriate
- Changed attr.ib() factory usage so cmd2 is compatible with older versions of attrs

4 files changed, 30 insertions, 25 deletions

diff --git a/cmd2/cmd2.py b/cmd2/cmd2.py
index db96228b..da5b528a 100644
--- a/cmd2/cmd2.py
+++ b/cmd2/cmd2.py
@@ -32,11 +32,11 @@ Git repository on GitHub at https://github.com/python-cmd2/cmd2
 import argparse
 import cmd
 import collections
+import colorama
 from colorama import Fore
 import glob
 import inspect
 import os
-import platform
 import re
 import shlex
 import sys
@@ -337,7 +337,7 @@ class Cmd(cmd.Cmd):
 
     # To make an attribute settable with the "do_set" command, add it to this ...
     # This starts out as a dictionary but gets converted to an OrderedDict sorted alphabetically by key
-    settable = {'colors': 'Allow colorized output',
+    settable = {'colors': 'Allow colorized output (valid values: Terminal, Always, Never)',
                 'continuation_prompt': 'On 2nd+ line of input',
                 'debug': 'Show full error stack on error',
                 'echo': 'Echo command issued into output',
@@ -369,6 +369,9 @@ class Cmd(cmd.Cmd):
             except AttributeError:
                 pass
 
+        # Override whether ansi codes should be stripped from the output since cmd2 has its own logic for doing this
+        colorama.init(strip=False)
+
         # initialize plugin system
         # needs to be done before we call __init__(0)
         self._initialize_plugin_system()
@@ -417,13 +420,13 @@ class Cmd(cmd.Cmd):
         self._STOP_AND_EXIT = True  # cmd convention
 
         self._colorcodes = {'bold': {True: '\x1b[1m', False: '\x1b[22m'},
-                            'cyan': {True: '\x1b[36m', False: '\x1b[39m'},
-                            'blue': {True: '\x1b[34m', False: '\x1b[39m'},
-                            'red': {True: '\x1b[31m', False: '\x1b[39m'},
-                            'magenta': {True: '\x1b[35m', False: '\x1b[39m'},
-                            'green': {True: '\x1b[32m', False: '\x1b[39m'},
-                            'underline': {True: '\x1b[4m', False: '\x1b[24m'},
-                            'yellow': {True: '\x1b[33m', False: '\x1b[39m'}}
+                            'cyan': {True: Fore.CYAN, False: Fore.RESET},
+                            'blue': {True: Fore.BLUE, False: Fore.RESET},
+                            'red': {True: Fore.RED, False: Fore.RESET},
+                            'magenta': {True: Fore.MAGENTA, False: Fore.RESET},
+                            'green': {True: Fore.GREEN, False: Fore.RESET},
+                            'underline': {True: '\x1b[4m', False: Fore.RESET},
+                            'yellow': {True: Fore.YELLOW, False: Fore.RESET}}
 
         # Used load command to store the current script dir as a LIFO queue to support _relative_load command
         self._script_dir = []
@@ -547,17 +550,15 @@ class Cmd(cmd.Cmd):
         # Make sure settable parameters are sorted alphabetically by key
         self.settable = collections.OrderedDict(sorted(self.settable.items(), key=lambda t: t[0]))
 
-    def decolorized_write(self, fileobj: IO, msg: str):
+    def decolorized_write(self, fileobj: IO, msg: str) -> None:
         """Write a string to a fileobject, stripping ANSI escape sequences if necessary
 
         Honor the current colors setting, which requires us to check whether the
         fileobject is a tty.
         """
-        if self.colors == constants.COLORS_NEVER:
+        if self.colors.lower() == constants.COLORS_NEVER.lower() or \
+                (self.colors.lower() == constants.COLORS_TERMINAL.lower() and not fileobj.isatty()):
             msg = utils.strip_ansi(msg)
-        if self.colors == constants.COLORS_TERMINAL:
-            if not fileobj.isatty():
-                msg = utils.strip_ansi(msg)
         fileobj.write(msg)
 
     def poutput(self, msg: Any, end: str='\n') -> None:
@@ -575,7 +576,7 @@ class Cmd(cmd.Cmd):
                 msg_str = '{}'.format(msg)
                 self.decolorized_write(self.stdout, msg_str)
                 if not msg_str.endswith(end):
-                    self.stdout.write(end)
+                    self.decolorized_write(self.stdout, end)
             except BrokenPipeError:
                 # This occurs if a command's output is being piped to another
                 # process and that process closes before the command is
@@ -615,7 +616,7 @@ class Cmd(cmd.Cmd):
             if self.feedback_to_output:
                 self.poutput(msg)
             else:
-                sys.stderr.write("{}\n".format(msg))
+                self.decolorized_write(sys.stderr, "{}\n".format(msg))
 
     def ppaged(self, msg: str, end: str='\n', chop: bool=False) -> None:
         """Print output using a pager if it would go off screen and stdout isn't currently being redirected.
@@ -651,6 +652,9 @@ class Cmd(cmd.Cmd):
                 # Don't attempt to use a pager that can block if redirecting or running a script (either text or Python)
                 # Also only attempt to use a pager if actually running in a real fully functional terminal
                 if functional_terminal and not self.redirecting and not self._in_py and not self._script_dir:
+                    if self.colors.lower() == constants.COLORS_NEVER.lower():
+                        msg_str = utils.strip_ansi(msg_str)
+
                     pager = self.pager
                     if chop:
                         pager = self.pager_chop
@@ -686,7 +690,7 @@ class Cmd(cmd.Cmd):
            is running on Windows, will return ``val`` unchanged.
            ``color`` should be one of the supported strings (or styles):
            red/blue/green/cyan/magenta, bold, underline"""
-        if self.colors and (self.stdout == self.initial_stdout):
+        if self.colors.lower() != constants.COLORS_NEVER.lower() and (self.stdout == self.initial_stdout):
             return self._colorcodes[color][True] + val + self._colorcodes[color][False]
         return val
 
diff --git a/cmd2/parsing.py b/cmd2/parsing.py
index 8edfacb9..92dc1b40 100644
--- a/cmd2/parsing.py
+++ b/cmd2/parsing.py
@@ -90,7 +90,7 @@ class Statement(str):
     command = attr.ib(default='', validator=attr.validators.instance_of(str), type=str)
 
     # list of arguments to the command, not including any output redirection or terminators; quoted args remain quoted
-    arg_list = attr.ib(factory=list, validator=attr.validators.instance_of(list), type=List[str])
+    arg_list = attr.ib(default=attr.Factory(list), validator=attr.validators.instance_of(list), type=List[str])
 
     # if the command is a multiline command, the name of the command, otherwise empty
     multiline_command = attr.ib(default='', validator=attr.validators.instance_of(str), type=str)
@@ -102,7 +102,7 @@ class Statement(str):
     suffix = attr.ib(default='', validator=attr.validators.instance_of(str), type=str)
 
     # if output was piped to a shell command, the shell command as a list of tokens
-    pipe_to = attr.ib(factory=list, validator=attr.validators.instance_of(list), type=List[str])
+    pipe_to = attr.ib(default=attr.Factory(list), validator=attr.validators.instance_of(list), type=List[str])
 
     # if output was redirected, the redirection token, i.e. '>>'
     output = attr.ib(default='', validator=attr.validators.instance_of(str), type=str)
diff --git a/examples/colors.py b/examples/colors.py
index 59e108b6..fb2de045 100755
--- a/examples/colors.py
+++ b/examples/colors.py
@@ -53,6 +53,7 @@ BG_COLORS ={
     'white':Back.WHITE,
 }
 
+
 class CmdLineApp(cmd2.Cmd):
     """Example cmd2 application demonstrating colorized output."""
 
@@ -71,14 +72,14 @@ class CmdLineApp(cmd2.Cmd):
         self.shortcuts.update({'&': 'speak'})
 
         # Set use_ipython to True to enable the "ipy" command which embeds and interactive IPython shell
-        super().__init__(use_ipython=False)
+        super().__init__(use_ipython=True)
 
     speak_parser = argparse.ArgumentParser()
     speak_parser.add_argument('-p', '--piglatin', action='store_true', help='atinLay')
     speak_parser.add_argument('-s', '--shout', action='store_true', help='N00B EMULATION MODE')
     speak_parser.add_argument('-r', '--repeat', type=int, help='output [n] times')
-    speak_parser.add_argument('-f', '--fg', help='foreground color to apply to output')
-    speak_parser.add_argument('-b', '--bg', help='background color to apply to output')
+    speak_parser.add_argument('-f', '--fg', choices=FG_COLORS, help='foreground color to apply to output')
+    speak_parser.add_argument('-b', '--bg', choices=BG_COLORS, help='background color to apply to output')
     speak_parser.add_argument('words', nargs='+', help='words to say')
 
     @cmd2.with_argparser(speak_parser)
@@ -95,9 +96,9 @@ class CmdLineApp(cmd2.Cmd):
         repetitions = args.repeat or 1
 
         color_on = ''
-        if args.fg and args.fg in FG_COLORS:
+        if args.fg:
             color_on += FG_COLORS[args.fg]
-        if args.bg and args.bg in BG_COLORS:
+        if args.bg:
             color_on += BG_COLORS[args.bg]
         color_off = Fore.RESET + Back.RESET
 
diff --git a/tests/conftest.py b/tests/conftest.py
index c86748e8..e177496b 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -94,7 +94,7 @@ timing: False
 """
 
 SHOW_LONG = """
-colors: Terminal          # Allow colorized output
+colors: Terminal          # Allow colorized output (valid values: Terminal, Always, Never)
 continuation_prompt: >    # On 2nd+ line of input
 debug: False              # Show full error stack on error
 echo: False               # Echo command issued into output