lambda formatting in f-string

In a formatted string using "lambda',  we should not add "\n".
For example in:
  f'{(lambda x:x)("8")!r}'

Adding a "\n" after "lambda x: x" will give an error message:
  SyntaxError: f-string expression part cannot include a backslash
This commit is contained in:
rocky
2022-04-12 16:49:58 -04:00
parent a1fe069c8c
commit 04510ac2f8
5 changed files with 58 additions and 42 deletions

View File

@@ -2,13 +2,17 @@
# String interpolation tests
# RUNNABLE!
var1 = 'x'
var2 = 'y'
abc = 'def'
assert (f"interpolate {var1} strings {var2!r} {var2!s} 'py36" ==
"interpolate x strings 'y' y 'py36")
assert 'def0' == f'{abc}0'
assert 'defdef' == f'{abc}{abc!s}'
"""This program is self-checking!"""
var1 = "x"
var2 = "y"
abc = "def"
assert (
f"interpolate {var1} strings {var2!r} {var2!s} 'py36"
== "interpolate x strings 'y' y 'py36"
)
assert "def0" == f"{abc}0"
assert "defdef" == f"{abc}{abc!s}"
# From 3.6 functools.py
# Bug was handling format operator strings.
@@ -21,51 +25,51 @@ assert y == "functools.1=['2'](2)"
# From 3.6 http/client.py
# Bug is in handling X
chunk = ['a', 'b', 'c']
chunk2 = 'd'
chunk = f'{len(chunk):X}' + chunk2
assert chunk == '3d'
chunk = ["a", "b", "c"]
chunk2 = "d"
chunk = f"{len(chunk):X}" + chunk2
assert chunk == "3d"
chunk = b'abc'
chunk2 = 'd'
chunk = f'{len(chunk):X}\r\n'.encode('ascii') + chunk \
+ b'\r\n'
assert chunk == b'3\r\nabc\r\n'
chunk = b"abc"
chunk2 = "d"
chunk = f"{len(chunk):X}\r\n".encode("ascii") + chunk + b"\r\n"
assert chunk == b"3\r\nabc\r\n"
# From 3.6.8 idlelib/pyshell.py
# Bug was handling '''
import os
filename = '.'
source = 'foo'
source = (f"__file__ = r'''{os.path.abspath(filename)}'''\n"
+ source + "\ndel __file__")
filename = "."
source = "foo"
source = f"__file__ = r'''{os.path.abspath(filename)}'''\n" + source + "\ndel __file__"
# Note how { and } are *not* escaped here
f = 'one'
name = 'two'
assert(f"{f}{'{{name}}'} {f}{'{name}'}") == 'one{{name}} one{name}'
f = "one"
name = "two"
assert (f"{f}{'{{name}}'} {f}{'{name}'}") == "one{{name}} one{name}"
# From 3.7.3 dataclasses.py
log_rounds = 5
assert "05$" == f'{log_rounds:02d}$'
log_rounds = 5
assert "05$" == f"{log_rounds:02d}$"
def testit(a, b, l):
# print(l)
return l
# The call below shows the need for BUILD_STRING to count expr arguments.
# Also note that we use {{ }} to escape braces in contrast to the example
# above.
def _repr_fn(fields):
return testit('__repr__',
('self',),
['return xx + f"(' +
', '.join([f"{f}={{self.{f}!r}}"
for f in fields]) +
')"'])
return testit(
"__repr__",
("self",),
['return xx + f"(' + ", ".join([f"{f}={{self.{f}!r}}" for f in fields]) + ')"'],
)
fields = ['a', 'b', 'c']
fields = ["a", "b", "c"]
assert _repr_fn(fields) == ['return xx + f"(a={self.a!r}, b={self.b!r}, c={self.c!r})"']
@@ -85,28 +89,31 @@ else:
assert False, "f'{lambda x:x}' should be a syntax error"
(x, y, width) = ("foo", 2, 10)
assert f'x={x*y:{width}}' == 'x=foofoo '
assert f"x={x*y:{width}}" == "x=foofoo "
# Why the fact that the distinction of docstring versus stmt is a
# string expression is important academic, but we will decompile an
# equivalent thing. For compatiblity with older Python we'll use "%"
# instead of a format string
def f():
f'''Not a docstring'''
f"""Not a docstring"""
def g():
'''Not a docstring''' \
f''
"""Not a docstring""" f""
assert f.__doc__ is None
assert g.__doc__ is None
import decimal
width, precision, value = (10, 4, decimal.Decimal('12.34567'))
width, precision, value = (10, 4, decimal.Decimal("12.34567"))
# Make sure we don't have additional f'..' inside the format strings below.
assert f'result: {value:{width}.{precision}}' == 'result: 12.35'
assert f'result: {value:{width:0}.{precision:1}}' == 'result: 12.35'
assert f'{2}\t' == '2\t'
assert f"result: {value:{width}.{precision}}" == "result: 12.35"
assert f"result: {value:{width:0}.{precision:1}}" == "result: 12.35"
assert f"{2}\t" == "2\t"
# But below we *do* need the additional f".."
assert f'{f"{0}"*3}' == "000"
@@ -115,4 +122,4 @@ assert f'{f"{0}"*3}' == "000"
# ^
# The former, {{ confuses the format strings so dictionary/set comprehensions
# don't work.
assert f'expr={ {x: y for x, y in [(1, 2), ]}}' == 'expr={1: 2}'
assert f"expr={ {x: y for x, y in [(1, 2), ]}}" == "expr={1: 2}"