mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-10-31 02:15:10 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 8
cpython/Lib/test/test_fstring.py

745 lines
27 KiB
Python
Raw Blame History

import ast
import types
import decimal
import unittest
a_global = 'global variable'
# You could argue that I'm too strict in looking for specific error
# values with assertRaisesRegex, but without it it's way too easy to
# make a syntax error in the test strings. Especially with all of the
# triple quotes, raw strings, backslashes, etc. I think it's a
# worthwhile tradeoff. When I switched to this method, I found many
# examples where I wasn't testing what I thought I was.
class TestCase(unittest.TestCase):
def assertAllRaise(self, exception_type, regex, error_strings):
for str in error_strings:
with self.subTest(str=str):
with self.assertRaisesRegex(exception_type, regex):
eval(str)
def test__format__lookup(self):
# Make sure __format__ is looked up on the type, not the instance.
class X:
def __format__(self, spec):
return 'class'
x = X()
# Add a bound __format__ method to the 'y' instance, but not
# the 'x' instance.
y = X()
y.__format__ = types.MethodType(lambda self, spec: 'instance', y)
self.assertEqual(f'{y}', format(y))
self.assertEqual(f'{y}', 'class')
self.assertEqual(format(x), format(y))
# __format__ is not called this way, but still make sure it
# returns what we expect (so we can make sure we're bypassing
# it).
self.assertEqual(x.__format__(''), 'class')
self.assertEqual(y.__format__(''), 'instance')
# This is how __format__ is actually called.
self.assertEqual(type(x).__format__(x, ''), 'class')
self.assertEqual(type(y).__format__(y, ''), 'class')
def test_ast(self):
# Inspired by http://bugs.python.org/issue24975
class X:
def __init__(self):
self.called = False
def __call__(self):
self.called = True
return 4
x = X()
expr = """
a = 10
f'{a * x()}'"""
t = ast.parse(expr)
c = compile(t, '', 'exec')
# Make sure x was not called.
self.assertFalse(x.called)
# Actually run the code.
exec(c)
# Make sure x was called.
self.assertTrue(x.called)
def test_literal_eval(self):
# With no expressions, an f-string is okay.
self.assertEqual(ast.literal_eval("f'x'"), 'x')
self.assertEqual(ast.literal_eval("f'x' 'y'"), 'xy')
# But this should raise an error.
with self.assertRaisesRegex(ValueError, 'malformed node or string'):
ast.literal_eval("f'x{3}'")
# As should this, which uses a different ast node
with self.assertRaisesRegex(ValueError, 'malformed node or string'):
ast.literal_eval("f'{3}'")
def test_ast_compile_time_concat(self):
x = ['']
expr = """x[0] = 'foo' f'{3}'"""
t = ast.parse(expr)
c = compile(t, '', 'exec')
exec(c)
self.assertEqual(x[0], 'foo3')
def test_literal(self):
self.assertEqual(f'', '')
self.assertEqual(f'a', 'a')
self.assertEqual(f' ', ' ')
self.assertEqual(f'\N{GREEK CAPITAL LETTER DELTA}',
'\N{GREEK CAPITAL LETTER DELTA}')
self.assertEqual(f'\N{GREEK CAPITAL LETTER DELTA}',
'\u0394')
self.assertEqual(f'\N{True}', '\u22a8')
self.assertEqual(rf'\N{True}', r'\NTrue')
def test_escape_order(self):
# note that hex(ord('{')) == 0x7b, so this
# string becomes f'a{4*10}b'
self.assertEqual(f'a\u007b4*10}b', 'a40b')
self.assertEqual(f'a\x7b4*10}b', 'a40b')
self.assertEqual(f'a\x7b4*10\N{RIGHT CURLY BRACKET}b', 'a40b')
self.assertEqual(f'{"a"!\N{LATIN SMALL LETTER R}}', "'a'")
self.assertEqual(f'{10\x3a02X}', '0A')
self.assertEqual(f'{10:02\N{LATIN CAPITAL LETTER X}}', '0A')
self.assertAllRaise(SyntaxError, "f-string: single '}' is not allowed",
[r"""f'a{\u007b4*10}b'""", # mis-matched brackets
])
self.assertAllRaise(SyntaxError, 'unexpected character after line continuation character',
[r"""f'{"a"\!r}'""",
r"""f'{a\!r}'""",
])
def test_unterminated_string(self):
self.assertAllRaise(SyntaxError, 'f-string: unterminated string',
[r"""f'{"x'""",
r"""f'{"x}'""",
r"""f'{("x'""",
r"""f'{("x}'""",
])
def test_mismatched_parens(self):
self.assertAllRaise(SyntaxError, 'f-string: mismatched',
["f'{((}'",
])
def test_double_braces(self):
self.assertEqual(f'{{', '{')
self.assertEqual(f'a{{', 'a{')
self.assertEqual(f'{{b', '{b')
self.assertEqual(f'a{{b', 'a{b')
self.assertEqual(f'}}', '}')
self.assertEqual(f'a}}', 'a}')
self.assertEqual(f'}}b', '}b')
self.assertEqual(f'a}}b', 'a}b')
self.assertEqual(f'{{{10}', '{10')
self.assertEqual(f'}}{10}', '}10')
self.assertEqual(f'}}{{{10}', '}{10')
self.assertEqual(f'}}a{{{10}', '}a{10')
self.assertEqual(f'{10}{{', '10{')
self.assertEqual(f'{10}}}', '10}')
self.assertEqual(f'{10}}}{{', '10}{')
self.assertEqual(f'{10}}}a{{' '}', '10}a{}')
# Inside of strings, don't interpret doubled brackets.
self.assertEqual(f'{"{{}}"}', '{{}}')
self.assertAllRaise(TypeError, 'unhashable type',
["f'{ {{}} }'", # dict in a set
])
def test_compile_time_concat(self):
x = 'def'
self.assertEqual('abc' f'## {x}ghi', 'abc## defghi')
self.assertEqual('abc' f'{x}' 'ghi', 'abcdefghi')
self.assertEqual('abc' f'{x}' 'gh' f'i{x:4}', 'abcdefghidef ')
self.assertEqual('{x}' f'{x}', '{x}def')
self.assertEqual('{x' f'{x}', '{xdef')
self.assertEqual('{x}' f'{x}', '{x}def')
self.assertEqual('{{x}}' f'{x}', '{{x}}def')
self.assertEqual('{{x' f'{x}', '{{xdef')
self.assertEqual('x}}' f'{x}', 'x}}def')
self.assertEqual(f'{x}' 'x}}', 'defx}}')
self.assertEqual(f'{x}' '', 'def')
self.assertEqual('' f'{x}' '', 'def')
self.assertEqual('' f'{x}', 'def')
self.assertEqual(f'{x}' '2', 'def2')
self.assertEqual('1' f'{x}' '2', '1def2')
self.assertEqual('1' f'{x}', '1def')
self.assertEqual(f'{x}' f'-{x}', 'def-def')
self.assertEqual('' f'', '')
self.assertEqual('' f'' '', '')
self.assertEqual('' f'' '' f'', '')
self.assertEqual(f'', '')
self.assertEqual(f'' '', '')
self.assertEqual(f'' '' f'', '')
self.assertEqual(f'' '' f'' '', '')
self.assertAllRaise(SyntaxError, "f-string: expecting '}'",
["f'{3' f'}'", # can't concat to get a valid f-string
])
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, "f-string cannot include '#'",
["f'{1#}'", # error because the expression becomes "(1#)"
"f'{3(#)}'",
])
def test_many_expressions(self):
# Create a string with many expressions in it. Note that
# because we have a space in here as a literal, we're actually
# going to use twice as many ast nodes: one for each literal
# plus one for each expression.
def build_fstr(n, extra=''):
return "f'" + ('{x} ' * n) + extra + "'"
x = 'X'
width = 1
# Test around 256.
for i in range(250, 260):
self.assertEqual(eval(build_fstr(i)), (x+' ')*i)
# Test concatenating 2 largs fstrings.
self.assertEqual(eval(build_fstr(255)*256), (x+' ')*(255*256))
s = build_fstr(253, '{x:{width}} ')
self.assertEqual(eval(s), (x+' ')*254)
# Test lots of expressions and constants, concatenated.
s = "f'{1}' 'x' 'y'" * 1024
self.assertEqual(eval(s), '1xy' * 1024)
def test_format_specifier_expressions(self):
width = 10
precision = 4
value = decimal.Decimal('12.34567')
self.assertEqual(f'result: {value:{width}.{precision}}', 'result: 12.35')
self.assertEqual(f'result: {value:{width!r}.{precision}}', 'result: 12.35')
self.assertEqual(f'result: {value:{width:0}.{precision:1}}', 'result: 12.35')
self.assertEqual(f'result: {value:{1}{0:0}.{precision:1}}', 'result: 12.35')
self.assertEqual(f'result: {value:{ 1}{ 0:0}.{ precision:1}}', 'result: 12.35')
self.assertEqual(f'{10:#{1}0x}', ' 0xa')
self.assertEqual(f'{10:{"#"}1{0}{"x"}}', ' 0xa')
self.assertEqual(f'{-10:-{"#"}1{0}x}', ' -0xa')
self.assertEqual(f'{-10:{"-"}#{1}0{"x"}}', ' -0xa')
self.assertEqual(f'{10:#{3 != {4:5} and width}x}', ' 0xa')
self.assertAllRaise(SyntaxError, "f-string: expecting '}'",
["""f'{"s"!r{":10"}}'""",
# This looks like a nested format spec.
])
self.assertAllRaise(SyntaxError, "invalid syntax",
[# Invalid sytax inside a nested spec.
"f'{4:{/5}}'",
])
self.assertAllRaise(SyntaxError, "f-string: expressions nested too deeply",
[# Can't nest format specifiers.
"f'result: {value:{width:{0}}.{precision:1}}'",
])
self.assertAllRaise(SyntaxError, 'f-string: invalid conversion character',
[# No expansion inside conversion or for
# the : or ! itself.
"""f'{"s"!{"r"}}'""",
])
def test_side_effect_order(self):
class X:
def __init__(self):
self.i = 0
def __format__(self, spec):
self.i += 1
return str(self.i)
x = X()
self.assertEqual(f'{x} {x}', '1 2')
def test_missing_expression(self):
self.assertAllRaise(SyntaxError, 'f-string: empty expression not allowed',
["f'{}'",
"f'{ }'"
"f' {} '",
"f'{!r}'",
"f'{ !r}'",
"f'{10:{ }}'",
"f' { } '",
r"f'{\n}'",
r"f'{\n \n}'",
# Catch the empty expression before the
# invalid conversion.
"f'{!x}'",
"f'{ !xr}'",
"f'{!x:}'",
"f'{!x:a}'",
"f'{ !xr:}'",
"f'{ !xr:a}'",
"f'{!}'",
"f'{:}'",
# We find the empty expression before the
# missing closing brace.
"f'{!'",
"f'{!s:'",
"f'{:'",
"f'{:x'",
])
def test_parens_in_expressions(self):
self.assertEqual(f'{3,}', '(3,)')
# Add these because when an expression is evaluated, parens
# are added around it. But we shouldn't go from an invalid
# expression to a valid one. The added parens are just
# supposed to allow whitespace (including newlines).
self.assertAllRaise(SyntaxError, 'invalid syntax',
["f'{,}'",
"f'{,}'", # this is (,), which is an error
])
self.assertAllRaise(SyntaxError, "f-string: expecting '}'",
["f'{3)+(4}'",
])
self.assertAllRaise(SyntaxError, 'EOL while scanning string literal',
["f'{\n}'",
])
def test_newlines_in_expressions(self):
self.assertEqual(f'{0}', '0')
self.assertEqual(f'{0\n}', '0')
self.assertEqual(f'{0\r}', '0')
self.assertEqual(f'{\n0\n}', '0')
self.assertEqual(f'{\r0\r}', '0')
self.assertEqual(f'{\n0\r}', '0')
self.assertEqual(f'{\n0}', '0')
self.assertEqual(f'{3+\n4}', '7')
self.assertEqual(f'{3+\\\n4}', '7')
self.assertEqual(rf'''{3+
4}''', '7')
self.assertEqual(f'''{3+\
4}''', '7')
self.assertAllRaise(SyntaxError, 'f-string: empty expression not allowed',
[r"f'{\n}'",
])
def test_lambda(self):
x = 5
self.assertEqual(f'{(lambda y:x*y)("8")!r}', "'88888'")
self.assertEqual(f'{(lambda y:x*y)("8")!r:10}', "'88888' ")
self.assertEqual(f'{(lambda y:x*y)("8"):10}', "88888 ")
# lambda doesn't work without parens, because the colon
# makes the parser think it's a format_spec
self.assertAllRaise(SyntaxError, 'unexpected EOF while parsing',
["f'{lambda x:x}'",
])
def test_yield(self):
# Not terribly useful, but make sure the yield turns
# a function into a generator
def fn(y):
f'y:{yield y*2}'
g = fn(4)
self.assertEqual(next(g), 8)
def test_yield_send(self):
def fn(x):
yield f'x:{yield (lambda i: x * i)}'
g = fn(10)
the_lambda = next(g)
self.assertEqual(the_lambda(4), 40)
self.assertEqual(g.send('string'), 'x:string')
def test_expressions_with_triple_quoted_strings(self):
self.assertEqual(f"{'''x'''}", 'x')
self.assertEqual(f"{'''eric's'''}", "eric's")
self.assertEqual(f'{"""eric\'s"""}', "eric's")
self.assertEqual(f"{'''eric\"s'''}", 'eric"s')
self.assertEqual(f'{"""eric"s"""}', 'eric"s')
# Test concatenation within an expression
self.assertEqual(f'{"x" """eric"s""" "y"}', 'xeric"sy')
self.assertEqual(f'{"x" """eric"s"""}', 'xeric"s')
self.assertEqual(f'{"""eric"s""" "y"}', 'eric"sy')
self.assertEqual(f'{"""x""" """eric"s""" "y"}', 'xeric"sy')
self.assertEqual(f'{"""x""" """eric"s""" """y"""}', 'xeric"sy')
self.assertEqual(f'{r"""x""" """eric"s""" """y"""}', 'xeric"sy')
def test_multiple_vars(self):
x = 98
y = 'abc'
self.assertEqual(f'{x}{y}', '98abc')
self.assertEqual(f'X{x}{y}', 'X98abc')
self.assertEqual(f'{x}X{y}', '98Xabc')
self.assertEqual(f'{x}{y}X', '98abcX')
self.assertEqual(f'X{x}Y{y}', 'X98Yabc')
self.assertEqual(f'X{x}{y}Y', 'X98abcY')
self.assertEqual(f'{x}X{y}Y', '98XabcY')
self.assertEqual(f'X{x}Y{y}Z', 'X98YabcZ')
def test_closure(self):
def outer(x):
def inner():
return f'x:{x}'
return inner
self.assertEqual(outer('987')(), 'x:987')
self.assertEqual(outer(7)(), 'x:7')
def test_arguments(self):
y = 2
def f(x, width):
return f'x={x*y:{width}}'
self.assertEqual(f('foo', 10), 'x=foofoo ')
x = 'bar'
self.assertEqual(f(10, 10), 'x= 20')
def test_locals(self):
value = 123
self.assertEqual(f'v:{value}', 'v:123')
def test_missing_variable(self):
with self.assertRaises(NameError):
f'v:{value}'
def test_missing_format_spec(self):
class O:
def __format__(self, spec):
if not spec:
return '*'
return spec
self.assertEqual(f'{O():x}', 'x')
self.assertEqual(f'{O()}', '*')
self.assertEqual(f'{O():}', '*')
self.assertEqual(f'{3:}', '3')
self.assertEqual(f'{3!s:}', '3')
def test_global(self):
self.assertEqual(f'g:{a_global}', 'g:global variable')
self.assertEqual(f'g:{a_global!r}', "g:'global variable'")
a_local = 'local variable'
self.assertEqual(f'g:{a_global} l:{a_local}',
'g:global variable l:local variable')
self.assertEqual(f'g:{a_global!r}',
"g:'global variable'")
self.assertEqual(f'g:{a_global} l:{a_local!r}',
"g:global variable l:'local variable'")
self.assertIn("module 'unittest' from", f'{unittest}')
def test_shadowed_global(self):
a_global = 'really a local'
self.assertEqual(f'g:{a_global}', 'g:really a local')
self.assertEqual(f'g:{a_global!r}', "g:'really a local'")
a_local = 'local variable'
self.assertEqual(f'g:{a_global} l:{a_local}',
'g:really a local l:local variable')
self.assertEqual(f'g:{a_global!r}',
"g:'really a local'")
self.assertEqual(f'g:{a_global} l:{a_local!r}',
"g:really a local l:'local variable'")
def test_call(self):
def foo(x):
return 'x=' + str(x)
self.assertEqual(f'{foo(10)}', 'x=10')
def test_nested_fstrings(self):
y = 5
self.assertEqual(f'{f"{0}"*3}', '000')
self.assertEqual(f'{f"{y}"*3}', '555')
self.assertEqual(f'{f"{\'x\'}"*3}', 'xxx')
self.assertEqual(f"{r'x' f'{\"s\"}'}", 'xs')
self.assertEqual(f"{r'x'rf'{\"s\"}'}", 'xs')
def test_invalid_string_prefixes(self):
self.assertAllRaise(SyntaxError, 'unexpected EOF while parsing',
["fu''",
"uf''",
"Fu''",
"fU''",
"Uf''",
"uF''",
"ufr''",
"urf''",
"fur''",
"fru''",
"rfu''",
"ruf''",
"FUR''",
"Fur''",
])
def test_leading_trailing_spaces(self):
self.assertEqual(f'{ 3}', '3')
self.assertEqual(f'{ 3}', '3')
self.assertEqual(f'{\t3}', '3')
self.assertEqual(f'{\t\t3}', '3')
self.assertEqual(f'{3 }', '3')
self.assertEqual(f'{3 }', '3')
self.assertEqual(f'{3\t}', '3')
self.assertEqual(f'{3\t\t}', '3')
self.assertEqual(f'expr={ {x: y for x, y in [(1, 2), ]}}',
'expr={1: 2}')
self.assertEqual(f'expr={ {x: y for x, y in [(1, 2), ]} }',
'expr={1: 2}')
def test_character_name(self):
self.assertEqual(f'{4}\N{GREEK CAPITAL LETTER DELTA}{3}',
'4\N{GREEK CAPITAL LETTER DELTA}3')
self.assertEqual(f'{{}}\N{GREEK CAPITAL LETTER DELTA}{3}',
'{}\N{GREEK CAPITAL LETTER DELTA}3')
def test_not_equal(self):
# There's a special test for this because there's a special
# case in the f-string parser to look for != as not ending an
# expression. Normally it would, while looking for !s or !r.
self.assertEqual(f'{3!=4}', 'True')
self.assertEqual(f'{3!=4:}', 'True')
self.assertEqual(f'{3!=4!s}', 'True')
self.assertEqual(f'{3!=4!s:.3}', 'Tru')
def test_conversions(self):
self.assertEqual(f'{3.14:10.10}', ' 3.14')
self.assertEqual(f'{3.14!s:10.10}', '3.14 ')
self.assertEqual(f'{3.14!r:10.10}', '3.14 ')
self.assertEqual(f'{3.14!a:10.10}', '3.14 ')
self.assertEqual(f'{"a"}', 'a')
self.assertEqual(f'{"a"!r}', "'a'")
self.assertEqual(f'{"a"!a}', "'a'")
# Not a conversion.
self.assertEqual(f'{"a!r"}', "a!r")
# Not a conversion, but show that ! is allowed in a format spec.
self.assertEqual(f'{3.14:!<10.10}', '3.14!!!!!!')
self.assertEqual(f'{"\N{GREEK CAPITAL LETTER DELTA}"}', '\u0394')
self.assertEqual(f'{"\N{GREEK CAPITAL LETTER DELTA}"!r}', "'\u0394'")
self.assertEqual(f'{"\N{GREEK CAPITAL LETTER DELTA}"!a}', "'\\u0394'")
self.assertAllRaise(SyntaxError, 'f-string: invalid conversion character',
["f'{3!g}'",
"f'{3!A}'",
"f'{3!A}'",
"f'{3!A}'",
"f'{3!!}'",
"f'{3!:}'",
"f'{3!\N{GREEK CAPITAL LETTER DELTA}}'",
"f'{3! s}'", # no space before conversion char
"f'{x!\\x00:.<10}'",
])
self.assertAllRaise(SyntaxError, "f-string: expecting '}'",
["f'{x!s{y}}'",
"f'{3!ss}'",
"f'{3!ss:}'",
"f'{3!ss:s}'",
])
def test_assignment(self):
self.assertAllRaise(SyntaxError, 'invalid syntax',
["f'' = 3",
"f'{0}' = x",
"f'{x}' = x",
])
def test_del(self):
self.assertAllRaise(SyntaxError, 'invalid syntax',
["del f''",
"del '' f''",
])
def test_mismatched_braces(self):
self.assertAllRaise(SyntaxError, "f-string: single '}' is not allowed",
["f'{{}'",
"f'{{}}}'",
"f'}'",
"f'x}'",
"f'x}x'",
# Can't have { or } in a format spec.
"f'{3:}>10}'",
r"f'{3:\\}>10}'",
"f'{3:}}>10}'",
])
self.assertAllRaise(SyntaxError, "f-string: expecting '}'",
["f'{3:{{>10}'",
"f'{3'",
"f'{3!'",
"f'{3:'",
"f'{3!s'",
"f'{3!s:'",
"f'{3!s:3'",
"f'x{'",
"f'x{x'",
"f'{3:s'",
"f'{{{'",
"f'{{}}{'",
"f'{'",
])
self.assertAllRaise(SyntaxError, 'invalid syntax',
[r"f'{3:\\{>10}'",
])
# But these are just normal strings.
self.assertEqual(f'{"{"}', '{')
self.assertEqual(f'{"}"}', '}')
self.assertEqual(f'{3:{"}"}>10}', '}}}}}}}}}3')
self.assertEqual(f'{2:{"{"}>10}', '{{{{{{{{{2')
def test_if_conditional(self):
# There's special logic in compile.c to test if the
# conditional for an if (and while) are constants. Exercise
# that code.
def test_fstring(x, expected):
flag = 0
if f'{x}':
flag = 1
else:
flag = 2
self.assertEqual(flag, expected)
def test_concat_empty(x, expected):
flag = 0
if '' f'{x}':
flag = 1
else:
flag = 2
self.assertEqual(flag, expected)
def test_concat_non_empty(x, expected):
flag = 0
if ' ' f'{x}':
flag = 1
else:
flag = 2
self.assertEqual(flag, expected)
test_fstring('', 2)
test_fstring(' ', 1)
test_concat_empty('', 2)
test_concat_empty(' ', 1)
test_concat_non_empty('', 1)
test_concat_non_empty(' ', 1)
def test_empty_format_specifier(self):
x = 'test'
self.assertEqual(f'{x}', 'test')
self.assertEqual(f'{x:}', 'test')
self.assertEqual(f'{x!s:}', 'test')
self.assertEqual(f'{x!r:}', "'test'")
def test_str_format_differences(self):
d = {'a': 'string',
0: 'integer',
}
a = 0
self.assertEqual(f'{d[0]}', 'integer')
self.assertEqual(f'{d["a"]}', 'string')
self.assertEqual(f'{d[a]}', 'integer')
self.assertEqual('{d[a]}'.format(d=d), 'string')
self.assertEqual('{d[0]}'.format(d=d), 'integer')
def test_invalid_expressions(self):
self.assertAllRaise(SyntaxError, 'invalid syntax',
[r"f'{a[4)}'",
r"f'{a(4]}'",
])
def test_errors(self):
# see issue 26287
self.assertAllRaise(TypeError, 'non-empty',
[r"f'{(lambda: 0):x}'",
r"f'{(0,):x}'",
])
self.assertAllRaise(ValueError, 'Unknown format code',
[r"f'{1000:j}'",
r"f'{1000:j}'",
])
def test_loop(self):
for i in range(1000):
self.assertEqual(f'i:{i}', 'i:' + str(i))
def test_dict(self):
d = {'"': 'dquote',
"'": 'squote',
'foo': 'bar',
}
self.assertEqual(f'{d["\'"]}', 'squote')
self.assertEqual(f"{d['\"']}", 'dquote')
self.assertEqual(f'''{d["'"]}''', 'squote')
self.assertEqual(f"""{d['"']}""", 'dquote')
self.assertEqual(f'{d["foo"]}', 'bar')
self.assertEqual(f"{d['foo']}", 'bar')
self.assertEqual(f'{d[\'foo\']}', 'bar')
self.assertEqual(f"{d[\"foo\"]}", 'bar')
def test_escaped_quotes(self):
d = {'"': 'a',
"'": 'b'}
self.assertEqual(fr"{d['\"']}", 'a')
self.assertEqual(fr'{d["\'"]}', 'b')
self.assertEqual(fr"{'\"'}", '"')
self.assertEqual(fr'{"\'"}', "'")
self.assertEqual(f'{"\\"3"}', '"3')
self.assertAllRaise(SyntaxError, 'f-string: unterminated string',
[r'''f'{"""\\}' ''', # Backslash at end of expression
])
self.assertAllRaise(SyntaxError, 'unexpected character after line continuation',
[r"rf'{3\}'",
])
if __name__ == '__main__':
unittest.main()
Reference in a new issue View git blame Copy permalink