271 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			Python
		
	
	
	
			
		
		
	
	
			271 lines
		
	
	
		
			7.5 KiB
		
	
	
	
		
			Python
		
	
	
	
| # SPDX-License-Identifier: GPL-2.0+
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| # Copyright (c) 2011 The Chromium OS Authors.
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| #
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| 
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| """Terminal utilities
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| 
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| This module handles terminal interaction including ANSI color codes.
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| """
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| 
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| import os
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| import re
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| import shutil
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| import sys
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| 
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| # Selection of when we want our output to be colored
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| COLOR_IF_TERMINAL, COLOR_ALWAYS, COLOR_NEVER = range(3)
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| 
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| # Initially, we are set up to print to the terminal
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| print_test_mode = False
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| print_test_list = []
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| 
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| # The length of the last line printed without a newline
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| last_print_len = None
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| 
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| # credit:
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| # stackoverflow.com/questions/14693701/how-can-i-remove-the-ansi-escape-sequences-from-a-string-in-python
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| ansi_escape = re.compile(r'\x1b(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])')
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| 
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| class PrintLine:
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|     """A line of text output
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| 
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|     Members:
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|         text: Text line that was printed
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|         newline: True to output a newline after the text
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|         colour: Text colour to use
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|     """
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|     def __init__(self, text, colour, newline=True, bright=True):
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|         self.text = text
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|         self.newline = newline
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|         self.colour = colour
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|         self.bright = bright
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| 
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|     def __eq__(self, other):
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|         return (self.text == other.text and
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|                 self.newline == other.newline and
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|                 self.colour == other.colour and
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|                 self.bright == other.bright)
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| 
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|     def __str__(self):
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|         return ("newline=%s, colour=%s, bright=%d, text='%s'" %
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|                 (self.newline, self.colour, self.bright, self.text))
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| 
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| 
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| def calc_ascii_len(text):
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|     """Calculate the length of a string, ignoring any ANSI sequences
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| 
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|     When displayed on a terminal, ANSI sequences don't take any space, so we
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|     need to ignore them when calculating the length of a string.
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| 
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|     Args:
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|         text: Text to check
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| 
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|     Returns:
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|         Length of text, after skipping ANSI sequences
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| 
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|     >>> col = Color(COLOR_ALWAYS)
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|     >>> text = col.build(Color.RED, 'abc')
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|     >>> len(text)
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|     14
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|     >>> calc_ascii_len(text)
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|     3
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|     >>>
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|     >>> text += 'def'
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|     >>> calc_ascii_len(text)
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|     6
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|     >>> text += col.build(Color.RED, 'abc')
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|     >>> calc_ascii_len(text)
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|     9
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|     """
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|     result = ansi_escape.sub('', text)
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|     return len(result)
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| 
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| def trim_ascii_len(text, size):
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|     """Trim a string containing ANSI sequences to the given ASCII length
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| 
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|     The string is trimmed with ANSI sequences being ignored for the length
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|     calculation.
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| 
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|     >>> col = Color(COLOR_ALWAYS)
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|     >>> text = col.build(Color.RED, 'abc')
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|     >>> len(text)
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|     14
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|     >>> calc_ascii_len(trim_ascii_len(text, 4))
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|     3
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|     >>> calc_ascii_len(trim_ascii_len(text, 2))
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|     2
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|     >>> text += 'def'
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|     >>> calc_ascii_len(trim_ascii_len(text, 4))
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|     4
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|     >>> text += col.build(Color.RED, 'ghi')
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|     >>> calc_ascii_len(trim_ascii_len(text, 7))
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|     7
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|     """
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|     if calc_ascii_len(text) < size:
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|         return text
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|     pos = 0
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|     out = ''
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|     left = size
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| 
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|     # Work through each ANSI sequence in turn
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|     for m in ansi_escape.finditer(text):
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|         # Find the text before the sequence and add it to our string, making
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|         # sure it doesn't overflow
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|         before = text[pos:m.start()]
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|         toadd = before[:left]
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|         out += toadd
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| 
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|         # Figure out how much non-ANSI space we have left
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|         left -= len(toadd)
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| 
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|         # Add the ANSI sequence and move to the position immediately after it
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|         out += m.group()
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|         pos = m.start() + len(m.group())
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| 
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|     # Deal with text after the last ANSI sequence
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|     after = text[pos:]
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|     toadd = after[:left]
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|     out += toadd
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| 
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|     return out
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| 
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| 
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| def tprint(text='', newline=True, colour=None, limit_to_line=False, bright=True):
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|     """Handle a line of output to the terminal.
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| 
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|     In test mode this is recorded in a list. Otherwise it is output to the
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|     terminal.
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| 
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|     Args:
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|         text: Text to print
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|         newline: True to add a new line at the end of the text
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|         colour: Colour to use for the text
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|     """
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|     global last_print_len
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| 
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|     if print_test_mode:
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|         print_test_list.append(PrintLine(text, colour, newline, bright))
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|     else:
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|         if colour:
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|             col = Color()
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|             text = col.build(colour, text, bright=bright)
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|         if newline:
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|             print(text)
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|             last_print_len = None
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|         else:
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|             if limit_to_line:
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|                 cols = shutil.get_terminal_size().columns
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|                 text = trim_ascii_len(text, cols)
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|             print(text, end='', flush=True)
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|             last_print_len = calc_ascii_len(text)
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| 
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| def print_clear():
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|     """Clear a previously line that was printed with no newline"""
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|     global last_print_len
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| 
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|     if last_print_len:
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|         print('\r%s\r' % (' '* last_print_len), end='', flush=True)
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|         last_print_len = None
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| 
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| def set_print_test_mode(enable=True):
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|     """Go into test mode, where all printing is recorded"""
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|     global print_test_mode
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| 
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|     print_test_mode = enable
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|     get_print_test_lines()
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| 
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| def get_print_test_lines():
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|     """Get a list of all lines output through tprint()
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| 
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|     Returns:
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|         A list of PrintLine objects
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|     """
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|     global print_test_list
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| 
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|     ret = print_test_list
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|     print_test_list = []
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|     return ret
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| 
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| def echo_print_test_lines():
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|     """Print out the text lines collected"""
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|     for line in print_test_list:
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|         if line.colour:
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|             col = Color()
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|             print(col.build(line.colour, line.text), end='')
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|         else:
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|             print(line.text, end='')
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|         if line.newline:
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|             print()
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| 
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| 
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| class Color(object):
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|     """Conditionally wraps text in ANSI color escape sequences."""
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|     BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = range(8)
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|     BOLD = -1
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|     BRIGHT_START = '\033[1;%dm'
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|     NORMAL_START = '\033[22;%dm'
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|     BOLD_START = '\033[1m'
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|     RESET = '\033[0m'
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| 
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|     def __init__(self, colored=COLOR_IF_TERMINAL):
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|         """Create a new Color object, optionally disabling color output.
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| 
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|         Args:
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|           enabled: True if color output should be enabled. If False then this
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|             class will not add color codes at all.
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|         """
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|         try:
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|             self._enabled = (colored == COLOR_ALWAYS or
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|                     (colored == COLOR_IF_TERMINAL and
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|                      os.isatty(sys.stdout.fileno())))
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|         except:
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|             self._enabled = False
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| 
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|     def start(self, color, bright=True):
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|         """Returns a start color code.
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| 
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|         Args:
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|           color: Color to use, .e.g BLACK, RED, etc.
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| 
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|         Returns:
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|           If color is enabled, returns an ANSI sequence to start the given
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|           color, otherwise returns empty string
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|         """
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|         if self._enabled:
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|             base = self.BRIGHT_START if bright else self.NORMAL_START
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|             return base % (color + 30)
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|         return ''
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| 
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|     def stop(self):
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|         """Returns a stop color code.
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| 
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|         Returns:
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|           If color is enabled, returns an ANSI color reset sequence,
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|           otherwise returns empty string
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|         """
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|         if self._enabled:
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|             return self.RESET
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|         return ''
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| 
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|     def build(self, color, text, bright=True):
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|         """Returns text with conditionally added color escape sequences.
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| 
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|         Keyword arguments:
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|           color: Text color -- one of the color constants defined in this
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|                   class.
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|           text: The text to color.
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| 
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|         Returns:
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|           If self._enabled is False, returns the original text. If it's True,
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|           returns text with color escape sequences based on the value of
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|           color.
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|         """
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|         if not self._enabled:
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|             return text
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|         if color == self.BOLD:
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|             start = self.BOLD_START
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|         else:
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|             base = self.BRIGHT_START if bright else self.NORMAL_START
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|             start = base % (color + 30)
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|         return start + text + self.RESET
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