1 import unittest
2 import sys
3 from io import StringIO
4
5 from test import support
6
7 NotDefined = object()
8
9 # A dispatch table all 8 combinations of providing
10 # sep, end, and file.
11 # I use this machinery so that I'm not just passing default
12 # values to print, I'm either passing or not passing in the
13 # arguments.
14 dispatch = {
15 (False, False, False):
16 lambda args, sep, end, file: print(*args),
17 (False, False, True):
18 lambda args, sep, end, file: print(file=file, *args),
19 (False, True, False):
20 lambda args, sep, end, file: print(end=end, *args),
21 (False, True, True):
22 lambda args, sep, end, file: print(end=end, file=file, *args),
23 (True, False, False):
24 lambda args, sep, end, file: print(sep=sep, *args),
25 (True, False, True):
26 lambda args, sep, end, file: print(sep=sep, file=file, *args),
27 (True, True, False):
28 lambda args, sep, end, file: print(sep=sep, end=end, *args),
29 (True, True, True):
30 lambda args, sep, end, file: print(sep=sep, end=end, file=file, *args),
31 }
32
33
34 # Class used to test __str__ and print
35 class ESC[4;38;5;81mClassWith__str__:
36 def __init__(self, x):
37 self.x = x
38
39 def __str__(self):
40 return self.x
41
42
43 class ESC[4;38;5;81mTestPrint(ESC[4;38;5;149munittestESC[4;38;5;149m.ESC[4;38;5;149mTestCase):
44 """Test correct operation of the print function."""
45
46 def check(self, expected, args,
47 sep=NotDefined, end=NotDefined, file=NotDefined):
48 # Capture sys.stdout in a StringIO. Call print with args,
49 # and with sep, end, and file, if they're defined. Result
50 # must match expected.
51
52 # Look up the actual function to call, based on if sep, end,
53 # and file are defined.
54 fn = dispatch[(sep is not NotDefined,
55 end is not NotDefined,
56 file is not NotDefined)]
57
58 with support.captured_stdout() as t:
59 fn(args, sep, end, file)
60
61 self.assertEqual(t.getvalue(), expected)
62
63 def test_print(self):
64 def x(expected, args, sep=NotDefined, end=NotDefined):
65 # Run the test 2 ways: not using file, and using
66 # file directed to a StringIO.
67
68 self.check(expected, args, sep=sep, end=end)
69
70 # When writing to a file, stdout is expected to be empty
71 o = StringIO()
72 self.check('', args, sep=sep, end=end, file=o)
73
74 # And o will contain the expected output
75 self.assertEqual(o.getvalue(), expected)
76
77 x('\n', ())
78 x('a\n', ('a',))
79 x('None\n', (None,))
80 x('1 2\n', (1, 2))
81 x('1 2\n', (1, ' ', 2))
82 x('1*2\n', (1, 2), sep='*')
83 x('1 s', (1, 's'), end='')
84 x('a\nb\n', ('a', 'b'), sep='\n')
85 x('1.01', (1.0, 1), sep='', end='')
86 x('1*a*1.3+', (1, 'a', 1.3), sep='*', end='+')
87 x('a\n\nb\n', ('a\n', 'b'), sep='\n')
88 x('\0+ +\0\n', ('\0', ' ', '\0'), sep='+')
89
90 x('a\n b\n', ('a\n', 'b'))
91 x('a\n b\n', ('a\n', 'b'), sep=None)
92 x('a\n b\n', ('a\n', 'b'), end=None)
93 x('a\n b\n', ('a\n', 'b'), sep=None, end=None)
94
95 x('*\n', (ClassWith__str__('*'),))
96 x('abc 1\n', (ClassWith__str__('abc'), 1))
97
98 # errors
99 self.assertRaises(TypeError, print, '', sep=3)
100 self.assertRaises(TypeError, print, '', end=3)
101 self.assertRaises(AttributeError, print, '', file='')
102
103 def test_print_flush(self):
104 # operation of the flush flag
105 class ESC[4;38;5;81mfilelike:
106 def __init__(self):
107 self.written = ''
108 self.flushed = 0
109
110 def write(self, str):
111 self.written += str
112
113 def flush(self):
114 self.flushed += 1
115
116 f = filelike()
117 print(1, file=f, end='', flush=True)
118 print(2, file=f, end='', flush=True)
119 print(3, file=f, flush=False)
120 self.assertEqual(f.written, '123\n')
121 self.assertEqual(f.flushed, 2)
122
123 # ensure exceptions from flush are passed through
124 class ESC[4;38;5;81mnoflush:
125 def write(self, str):
126 pass
127
128 def flush(self):
129 raise RuntimeError
130 self.assertRaises(RuntimeError, print, 1, file=noflush(), flush=True)
131
132
133 class ESC[4;38;5;81mTestPy2MigrationHint(ESC[4;38;5;149munittestESC[4;38;5;149m.ESC[4;38;5;149mTestCase):
134 """Test that correct hint is produced analogous to Python3 syntax,
135 if print statement is executed as in Python 2.
136 """
137
138 def test_normal_string(self):
139 python2_print_str = 'print "Hello World"'
140 with self.assertRaises(SyntaxError) as context:
141 exec(python2_print_str)
142
143 self.assertIn("Missing parentheses in call to 'print'. Did you mean print(...)",
144 str(context.exception))
145
146 def test_string_with_soft_space(self):
147 python2_print_str = 'print "Hello World",'
148 with self.assertRaises(SyntaxError) as context:
149 exec(python2_print_str)
150
151 self.assertIn("Missing parentheses in call to 'print'. Did you mean print(...)",
152 str(context.exception))
153
154 def test_string_with_excessive_whitespace(self):
155 python2_print_str = 'print "Hello World", '
156 with self.assertRaises(SyntaxError) as context:
157 exec(python2_print_str)
158
159 self.assertIn("Missing parentheses in call to 'print'. Did you mean print(...)",
160 str(context.exception))
161
162 def test_string_with_leading_whitespace(self):
163 python2_print_str = '''if 1:
164 print "Hello World"
165 '''
166 with self.assertRaises(SyntaxError) as context:
167 exec(python2_print_str)
168
169 self.assertIn("Missing parentheses in call to 'print'. Did you mean print(...)",
170 str(context.exception))
171
172 # bpo-32685: Suggestions for print statement should be proper when
173 # it is in the same line as the header of a compound statement
174 # and/or followed by a semicolon
175 def test_string_with_semicolon(self):
176 python2_print_str = 'print p;'
177 with self.assertRaises(SyntaxError) as context:
178 exec(python2_print_str)
179
180 self.assertIn("Missing parentheses in call to 'print'. Did you mean print(...)",
181 str(context.exception))
182
183 def test_string_in_loop_on_same_line(self):
184 python2_print_str = 'for i in s: print i'
185 with self.assertRaises(SyntaxError) as context:
186 exec(python2_print_str)
187
188 self.assertIn("Missing parentheses in call to 'print'. Did you mean print(...)",
189 str(context.exception))
190
191 def test_stream_redirection_hint_for_py2_migration(self):
192 # Test correct hint produced for Py2 redirection syntax
193 with self.assertRaises(TypeError) as context:
194 print >> sys.stderr, "message"
195 self.assertIn('Did you mean "print(<message>, '
196 'file=<output_stream>)"?', str(context.exception))
197
198 # Test correct hint is produced in the case where RHS implements
199 # __rrshift__ but returns NotImplemented
200 with self.assertRaises(TypeError) as context:
201 print >> 42
202 self.assertIn('Did you mean "print(<message>, '
203 'file=<output_stream>)"?', str(context.exception))
204
205 # Test stream redirection hint is specific to print
206 with self.assertRaises(TypeError) as context:
207 max >> sys.stderr
208 self.assertNotIn('Did you mean ', str(context.exception))
209
210 # Test stream redirection hint is specific to rshift
211 with self.assertRaises(TypeError) as context:
212 print << sys.stderr
213 self.assertNotIn('Did you mean', str(context.exception))
214
215 # Ensure right operand implementing rrshift still works
216 class ESC[4;38;5;81mOverrideRRShift:
217 def __rrshift__(self, lhs):
218 return 42 # Force result independent of LHS
219
220 self.assertEqual(print >> OverrideRRShift(), 42)
221
222
223
224 if __name__ == "__main__":
225 unittest.main()