summaryrefslogtreecommitdiff
path: root/Lib/test/test_print.py
blob: 394a2f19b6d3abd1ce495e46923e0db3e49e42bc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
"""Test correct operation of the print function.
"""

# In 2.6, this gives us the behavior we want.  In 3.0, it has
#  no function, but it still must parse correctly.
from __future__ import print_function

import unittest
from test import test_support

import sys
from StringIO import StringIO

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 eiher 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):
    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 test_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))

        # 2.x unicode tests
        x(u'1 2\n', ('1', u'2'))
        x(u'u\1234\n', (u'u\1234',))
        x(u'  abc 1\n', (' ', ClassWith__str__(u'abc'), 1))

        # errors
        self.assertRaises(TypeError, print, '', sep=3)
        self.assertRaises(TypeError, print, '', end=3)
        self.assertRaises(AttributeError, print, '', file='')

    def test_mixed_args(self):
        # If an unicode arg is passed, sep and end should be unicode, too.
        class Recorder(object):

            def __init__(self, must_be_unicode):
                self.buf = []
                self.force_unicode = must_be_unicode

            def write(self, what):
                if self.force_unicode and not isinstance(what, unicode):
                    raise AssertionError("{0!r} is not unicode".format(what))
                self.buf.append(what)

        buf = Recorder(True)
        print(u'hi', file=buf)
        self.assertEqual(u''.join(buf.buf), 'hi\n')
        del buf.buf[:]
        print(u'hi', u'nothing', file=buf)
        self.assertEqual(u''.join(buf.buf), 'hi nothing\n')
        buf = Recorder(False)
        print('hi', 'bye', end=u'\n', file=buf)
        self.assertTrue(isinstance(buf.buf[1], unicode))
        self.assertTrue(isinstance(buf.buf[3], unicode))
        del buf.buf[:]
        print(sep=u'x', file=buf)
        self.assertTrue(isinstance(buf.buf[-1], unicode))


def test_main():
    test_support.run_unittest(TestPrint)

if __name__ == "__main__":
    test_main()