Method test_comments

Lib/test/test_fstring.py:738–787

(self)

                             ])

    def test_comments(self):
        # These aren't comments, since they're in strings.
        d = {'#': 'hash'}
        self.assertEqual(f'{"#"}', '#')
        self.assertEqual(f'{d["#"]}', 'hash')

        self.assertAllRaise(SyntaxError, "'{' was never closed",
                            ["f'{1#}'",   # error because everything after '#' is a comment
                             "f'{#}'",
                             "f'one: {1#}'",
                             "f'{1# one} {2 this is a comment still#}'",
                             ])
        self.assertAllRaise(SyntaxError, r"f-string: unmatched '\)'",
                            ["f'{)#}'",   # When wrapped in parens, this becomes
                                          #  '()#)'.  Make sure that doesn't compile.
                             ])
        self.assertEqual(f'''A complex trick: {
2  # two
}''', 'A complex trick: 2')
        self.assertEqual(f'''
{
40 # forty
+  # plus
2  # two
}''', '\n42')
        self.assertEqual(f'''
{
40 # forty
+  # plus
2  # two
}''', '\n42')

        self.assertEqual(f'''
# this is not a comment
{ # the following operation it's
3 # this is a number
* 2}''', '\n# this is not a comment\n6')
        self.assertEqual(f'''
{# f'a {comment}'
86 # constant
# nothing more
}''', '\n86')

        self.assertAllRaise(SyntaxError, r"f-string: valid expression required before '}'",
                            ["""f'''
{
# only a comment
}'''
""", # this is equivalent to f'{}'
                             ])

    def test_many_expressions(self):
        # Create a string with many expressions in it. Note that