| import unittest |
| import sys |
| from io import StringIO |
| |
| from test import support |
| |
| NotDefined = object() |
| |
| # A dispatch table all 8 combinations of providing |
| # sep, end, and file. |
| # I use this machinery so that I'm not just passing default |
| # values to print, I'm either passing or not passing in the |
| # arguments. |
| dispatch = { |
| (False, False, False): |
| lambda args, sep, end, file: print(*args), |
| (False, False, True): |
| lambda args, sep, end, file: print(file=file, *args), |
| (False, True, False): |
| lambda args, sep, end, file: print(end=end, *args), |
| (False, True, True): |
| lambda args, sep, end, file: print(end=end, file=file, *args), |
| (True, False, False): |
| lambda args, sep, end, file: print(sep=sep, *args), |
| (True, False, True): |
| lambda args, sep, end, file: print(sep=sep, file=file, *args), |
| (True, True, False): |
| lambda args, sep, end, file: print(sep=sep, end=end, *args), |
| (True, True, True): |
| lambda args, sep, end, file: print(sep=sep, end=end, file=file, *args), |
| } |
| |
| |
| # Class used to test __str__ and print |
| class ClassWith__str__: |
| def __init__(self, x): |
| self.x = x |
| |
| def __str__(self): |
| return self.x |
| |
| |
| class TestPrint(unittest.TestCase): |
| """Test correct operation of the print function.""" |
| |
| def check(self, expected, args, |
| sep=NotDefined, end=NotDefined, file=NotDefined): |
| # Capture sys.stdout in a StringIO. Call print with args, |
| # and with sep, end, and file, if they're defined. Result |
| # must match expected. |
| |
| # Look up the actual function to call, based on if sep, end, |
| # and file are defined. |
| fn = dispatch[(sep is not NotDefined, |
| end is not NotDefined, |
| file is not NotDefined)] |
| |
| with support.captured_stdout() as t: |
| fn(args, sep, end, file) |
| |
| self.assertEqual(t.getvalue(), expected) |
| |
| def test_print(self): |
| def x(expected, args, sep=NotDefined, end=NotDefined): |
| # Run the test 2 ways: not using file, and using |
| # file directed to a StringIO. |
| |
| self.check(expected, args, sep=sep, end=end) |
| |
| # When writing to a file, stdout is expected to be empty |
| o = StringIO() |
| self.check('', args, sep=sep, end=end, file=o) |
| |
| # And o will contain the expected output |
| self.assertEqual(o.getvalue(), expected) |
| |
| x('\n', ()) |
| x('a\n', ('a',)) |
| x('None\n', (None,)) |
| x('1 2\n', (1, 2)) |
| x('1 2\n', (1, ' ', 2)) |
| x('1*2\n', (1, 2), sep='*') |
| x('1 s', (1, 's'), end='') |
| x('a\nb\n', ('a', 'b'), sep='\n') |
| x('1.01', (1.0, 1), sep='', end='') |
| x('1*a*1.3+', (1, 'a', 1.3), sep='*', end='+') |
| x('a\n\nb\n', ('a\n', 'b'), sep='\n') |
| x('\0+ +\0\n', ('\0', ' ', '\0'), sep='+') |
| |
| x('a\n b\n', ('a\n', 'b')) |
| x('a\n b\n', ('a\n', 'b'), sep=None) |
| x('a\n b\n', ('a\n', 'b'), end=None) |
| x('a\n b\n', ('a\n', 'b'), sep=None, end=None) |
| |
| x('*\n', (ClassWith__str__('*'),)) |
| x('abc 1\n', (ClassWith__str__('abc'), 1)) |
| |
| # errors |
| self.assertRaises(TypeError, print, '', sep=3) |
| self.assertRaises(TypeError, print, '', end=3) |
| self.assertRaises(AttributeError, print, '', file='') |
| |
| def test_print_flush(self): |
| # operation of the flush flag |
| class filelike: |
| def __init__(self): |
| self.written = '' |
| self.flushed = 0 |
| |
| def write(self, str): |
| self.written += str |
| |
| def flush(self): |
| self.flushed += 1 |
| |
| f = filelike() |
| print(1, file=f, end='', flush=True) |
| print(2, file=f, end='', flush=True) |
| print(3, file=f, flush=False) |
| self.assertEqual(f.written, '123\n') |
| self.assertEqual(f.flushed, 2) |
| |
| # ensure exceptions from flush are passed through |
| class noflush: |
| def write(self, str): |
| pass |
| |
| def flush(self): |
| raise RuntimeError |
| self.assertRaises(RuntimeError, print, 1, file=noflush(), flush=True) |
| |
| |
| class TestPy2MigrationHint(unittest.TestCase): |
| """Test that correct hint is produced analogous to Python3 syntax, |
| if print statement is executed as in Python 2. |
| """ |
| |
| def test_normal_string(self): |
| python2_print_str = 'print "Hello World"' |
| with self.assertRaises(SyntaxError) as context: |
| exec(python2_print_str) |
| |
| self.assertIn('print("Hello World")', str(context.exception)) |
| |
| def test_string_with_soft_space(self): |
| python2_print_str = 'print "Hello World",' |
| with self.assertRaises(SyntaxError) as context: |
| exec(python2_print_str) |
| |
| self.assertIn('print("Hello World", end=" ")', str(context.exception)) |
| |
| def test_string_with_excessive_whitespace(self): |
| python2_print_str = 'print "Hello World", ' |
| with self.assertRaises(SyntaxError) as context: |
| exec(python2_print_str) |
| |
| self.assertIn('print("Hello World", end=" ")', str(context.exception)) |
| |
| def test_string_with_leading_whitespace(self): |
| python2_print_str = '''if 1: |
| print "Hello World" |
| ''' |
| with self.assertRaises(SyntaxError) as context: |
| exec(python2_print_str) |
| |
| self.assertIn('print("Hello World")', str(context.exception)) |
| |
| # bpo-32685: Suggestions for print statement should be proper when |
| # it is in the same line as the header of a compound statement |
| # and/or followed by a semicolon |
| def test_string_with_semicolon(self): |
| python2_print_str = 'print p;' |
| with self.assertRaises(SyntaxError) as context: |
| exec(python2_print_str) |
| |
| self.assertIn('print(p)', str(context.exception)) |
| |
| def test_string_in_loop_on_same_line(self): |
| python2_print_str = 'for i in s: print i' |
| with self.assertRaises(SyntaxError) as context: |
| exec(python2_print_str) |
| |
| self.assertIn('print(i)', str(context.exception)) |
| |
| def test_stream_redirection_hint_for_py2_migration(self): |
| # Test correct hint produced for Py2 redirection syntax |
| with self.assertRaises(TypeError) as context: |
| print >> sys.stderr, "message" |
| self.assertIn('Did you mean "print(<message>, ' |
| 'file=<output_stream>)"?', str(context.exception)) |
| |
| # Test correct hint is produced in the case where RHS implements |
| # __rrshift__ but returns NotImplemented |
| with self.assertRaises(TypeError) as context: |
| print >> 42 |
| self.assertIn('Did you mean "print(<message>, ' |
| 'file=<output_stream>)"?', str(context.exception)) |
| |
| # Test stream redirection hint is specific to print |
| with self.assertRaises(TypeError) as context: |
| max >> sys.stderr |
| self.assertNotIn('Did you mean ', str(context.exception)) |
| |
| # Test stream redirection hint is specific to rshift |
| with self.assertRaises(TypeError) as context: |
| print << sys.stderr |
| self.assertNotIn('Did you mean', str(context.exception)) |
| |
| # Ensure right operand implementing rrshift still works |
| class OverrideRRShift: |
| def __rrshift__(self, lhs): |
| return 42 # Force result independent of LHS |
| |
| self.assertEqual(print >> OverrideRRShift(), 42) |
| |
| |
| |
| if __name__ == "__main__": |
| unittest.main() |