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			144 lines
		
	
	
	
		
			4.6 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			144 lines
		
	
	
	
		
			4.6 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| """Test correct operation of the print function.
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| """
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| 
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| # In 2.6, this gives us the behavior we want.  In 3.0, it has
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| #  no function, but it still must parse correctly.
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| from __future__ import print_function
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| 
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| import unittest
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| from test import support
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| 
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| try:
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|     # 3.x
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|     from io import StringIO
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| except ImportError:
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|     # 2.x
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|     from StringIO import StringIO
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| 
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| NotDefined = object()
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| 
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| # A dispatch table all 8 combinations of providing
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| #  sep, end, and file
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| # I use this machinery so that I'm not just passing default
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| #  values to print, I'm either passing or not passing in the
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| #  arguments
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| dispatch = {
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|     (False, False, False):
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|      lambda args, sep, end, file: print(*args),
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|     (False, False, True):
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|      lambda args, sep, end, file: print(file=file, *args),
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|     (False, True,  False):
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|      lambda args, sep, end, file: print(end=end, *args),
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|     (False, True,  True):
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|      lambda args, sep, end, file: print(end=end, file=file, *args),
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|     (True,  False, False):
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|      lambda args, sep, end, file: print(sep=sep, *args),
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|     (True,  False, True):
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|      lambda args, sep, end, file: print(sep=sep, file=file, *args),
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|     (True,  True,  False):
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|      lambda args, sep, end, file: print(sep=sep, end=end, *args),
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|     (True,  True,  True):
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|      lambda args, sep, end, file: print(sep=sep, end=end, file=file, *args),
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|     }
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| 
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| # Class used to test __str__ and print
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| class ClassWith__str__:
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|     def __init__(self, x):
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|         self.x = x
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|     def __str__(self):
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|         return self.x
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| 
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| class TestPrint(unittest.TestCase):
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|     def check(self, expected, args,
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|             sep=NotDefined, end=NotDefined, file=NotDefined):
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|         # Capture sys.stdout in a StringIO.  Call print with args,
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|         #  and with sep, end, and file, if they're defined.  Result
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|         #  must match expected.
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| 
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|         # Look up the actual function to call, based on if sep, end, and file
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|         #  are defined
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|         fn = dispatch[(sep is not NotDefined,
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|                        end is not NotDefined,
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|                        file is not NotDefined)]
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| 
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|         with support.captured_stdout() as t:
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|             fn(args, sep, end, file)
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| 
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|         self.assertEqual(t.getvalue(), expected)
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| 
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|     def test_print(self):
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|         def x(expected, args, sep=NotDefined, end=NotDefined):
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|             # Run the test 2 ways: not using file, and using
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|             #  file directed to a StringIO
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| 
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|             self.check(expected, args, sep=sep, end=end)
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| 
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|             # When writing to a file, stdout is expected to be empty
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|             o = StringIO()
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|             self.check('', args, sep=sep, end=end, file=o)
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| 
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|             # And o will contain the expected output
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|             self.assertEqual(o.getvalue(), expected)
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| 
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|         x('\n', ())
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|         x('a\n', ('a',))
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|         x('None\n', (None,))
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|         x('1 2\n', (1, 2))
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|         x('1   2\n', (1, ' ', 2))
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|         x('1*2\n', (1, 2), sep='*')
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|         x('1 s', (1, 's'), end='')
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|         x('a\nb\n', ('a', 'b'), sep='\n')
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|         x('1.01', (1.0, 1), sep='', end='')
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|         x('1*a*1.3+', (1, 'a', 1.3), sep='*', end='+')
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|         x('a\n\nb\n', ('a\n', 'b'), sep='\n')
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|         x('\0+ +\0\n', ('\0', ' ', '\0'), sep='+')
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| 
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|         x('a\n b\n', ('a\n', 'b'))
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|         x('a\n b\n', ('a\n', 'b'), sep=None)
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|         x('a\n b\n', ('a\n', 'b'), end=None)
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|         x('a\n b\n', ('a\n', 'b'), sep=None, end=None)
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| 
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|         x('*\n', (ClassWith__str__('*'),))
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|         x('abc 1\n', (ClassWith__str__('abc'), 1))
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| 
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| #        # 2.x unicode tests
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| #        x(u'1 2\n', ('1', u'2'))
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| #        x(u'u\1234\n', (u'u\1234',))
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| #        x(u'  abc 1\n', (' ', ClassWith__str__(u'abc'), 1))
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| 
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|         # errors
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|         self.assertRaises(TypeError, print, '', sep=3)
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|         self.assertRaises(TypeError, print, '', end=3)
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|         self.assertRaises(AttributeError, print, '', file='')
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| 
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|     def test_print_flush(self):
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|         # operation of the flush flag
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|         class filelike():
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|             def __init__(self):
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|                 self.written = ''
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|                 self.flushed = 0
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|             def write(self, str):
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|                 self.written += str
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|             def flush(self):
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|                 self.flushed += 1
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| 
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|         f = filelike()
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|         print(1, file=f, end='', flush=True)
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|         print(2, file=f, end='', flush=True)
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|         print(3, file=f, flush=False)
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|         self.assertEqual(f.written, '123\n')
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|         self.assertEqual(f.flushed, 2)
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| 
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|         # ensure exceptions from flush are passed through
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|         class noflush():
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|             def write(self, str):
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|                 pass
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|             def flush(self):
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|                 raise RuntimeError
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|         self.assertRaises(RuntimeError, print, 1, file=noflush(), flush=True)
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| 
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| def test_main():
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|     support.run_unittest(TestPrint)
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| 
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| if __name__ == "__main__":
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|     test_main()
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