Regressed in 6.1.0 in 62e249a1f9.
The `x` is an `str` but is expected to be a `pathlib.Path`. Not caught
by mypy because `config.getini()` returns `Any`.
Fix by just removing the `bestrelpath` call:
- testpaths are always relative to the rootdir, it thus would be very
unusual to specify an absolute path there.
- The code was wrong even before the regression: `py.path.local`'s
`bestrelpath` function expects a `py.path.local`, not an `str`. But it
had some weird `try ... except AttributeError` fallback which just
returns the argument, i.e. it was a no-op. So there is no behavior
change.
- It seems reasonable to me to just print the full path if that's what
the ini specifies.
When switching from py.path.local to pathlib (70f3ad1c1f),
`local.parts(reverse=True)` was translated incorrectly, leading to the
wrong rootdir being determined in some non-trivial cases where parent
directories have config files as well.
This indicates at least for people using type checkers that these
classes are not designed for inheritance and we make no stability
guarantees regarding inheritance of them.
Currently this doesn't show up in the docs. Sphinx does actually support
`@final`, however it only works when imported directly from `typing`,
while we import from `_pytest.compat`.
In the future there might also be a `@sealed` decorator which would
cover some more cases.
For decorated functions, the lineno of the FunctionDef AST node points
to the `def` line, not to the first decorator line. On the other hand,
in code objects, the `co_firstlineno` points to the first decorator
line.
Assertion rewriting inserts some imports to code it rewrites. The
imports are inserted at the lineno of the first statement in the AST. In
turn, the code object compiled from the rewritten AST uses the lineno of
the first statement (which is the first inserted import).
This means that given a module like this,
```py
@foo
@bar
def baz(): pass
```
the lineno of the code object without assertion rewriting
(`--assertion=plain`) is 1, but with assertion rewriting it is 3.
And *this* causes some issues for the exception repr when e.g. the
decorator line is invalid and raises during collection. The code becomes
confused and crashes with
INTERNALERROR> File "_pytest/_code/code.py", line 638, in get_source
INTERNALERROR> lines.append(space_prefix + source.lines[line_index].strip())
INTERNALERROR> IndexError: list index out of range
Fix it by special casing decorators. Maybe there are other cases like
this but off hand I can't think of another Python construct where the
lineno of the item would be after its first line, and this is the only
such issue we have had reported.
When a name is exported from `pytest`, prefer to refer to it by that
rather than its `_pytest` import path. It is shorter and more
appropriate in user-facing documentation (although that's not really
visible).
Our plan is to expose more names for typing purposes, in which can this
could be more comprehensive.
Warnings are a central part of Python, so much that Python itself has
command-line and environtment variables to handle warnings.
By moving the concept of warning handling into Config, it becomes natural to
filter warnings issued as early as possible, even before the "_pytest.warnings"
plugin is given a chance to spring into action. This also avoids the weird
coupling between config and the warnings plugin that was required before.
Fix#6681Fix#2891Fix#7620Fix#7626Close#7649
Co-authored-by: Ran Benita <ran@unusedvar.com>
Inline `_makeitem()` so that `self.ihook` (which is moderately
expensive) can be called only once.
Note: the removed test "test_makeitem_non_underscore" comes from an old
behavior of skipping names that start with `_` which has since been
generalized, making the test no longer relevant.
When a Python object (module/class/instance) is collected, for each name
in `obj.__dict__` (and up its MRO) the pytest_pycollect_makeitem hook is
called for potentially creating a node for it.
These Python objects have a bunch of builtin attributes that are
extremely unlikely to be collected. But due to their pervasiveness,
dispatching the hook for them ends up being mildly expensive and also
pollutes PYTEST_DEBUG=1 output and such.
Let's just ignore these attributes.
On the pandas test suite commit 04e9e0afd476b1b8bed930e47bf60e,
collect only, irrelevant lines snipped, about 5% improvement:
Before:
```
51195095 function calls (48844352 primitive calls) in 39.089 seconds
ncalls tottime percall cumtime percall filename:lineno(function)
226602/54 0.145 0.000 38.940 0.721 manager.py:90(_hookexec)
72227 0.285 0.000 20.146 0.000 python.py:424(_makeitem)
72227 0.171 0.000 16.678 0.000 python.py:218(pytest_pycollect_makeitem)
```
After:
```
48410921 function calls (46240870 primitive calls) in 36.950 seconds
ncalls tottime percall cumtime percall filename:lineno(function)
181429/54 0.113 0.000 36.777 0.681 manager.py:90(_hookexec)
27054 0.130 0.000 17.755 0.001 python.py:465(_makeitem)
27054 0.121 0.000 16.219 0.001 python.py:218(pytest_pycollect_makeitem)
```
In ff8b7884e8 NOTSET was changed to a
singleton enum, which ended up unexpectedly triggering a code path in ID
generation which checks for `isinstance(Enum)`.
Add an explicit case for it, which is not too bad anyway.
This is a more sensible interface for matchnodes.
This also fixes a sort-of bug where a recursive call to matchnodes
raises NoMatch which would terminate the entire tree, even if other
branches may find a match. Though I don't think it's actually possible.
This reverts commit f10ab021e2.
The commit was good in that it removed a non-trivial amount of code
duplication. However it was done in the wrong layer (nodes.py) and split
up a major part of the collection (the filesystem traversal) to a
separate class making it harder to understand.
We should try to reduce the duplication, but in a more appropriate
manner.
The path part of a `<path>::part1::part2` style collection argument must
be a file, not a directory.
Previously this crashed with an uncool assert "invalid arg".
The `CaptureManager.global_and_fixture_disabled()` context manager (and
`CaptureFixture.disabled()` which calls it) did `suspend(); ...;
resume()` but if the capturing was already suspended, the `resume()`
would resume it when it shouldn't.
This caused caused some messages to be swallowed when `--log-cli` is
used because it uses `global_and_fixture_disabled` when capturing is not
necessarily resumed.
This fixes an issue where pylint complains about missing implementations
of abstract methods in subclasses of `File` which only override
`collect()` (as they should).
It is also cleaner and makes sense, these methods really don't need to
be overridden.
The previous methods defined directly on `FSCollector` and `Package` are
deprecated, to be removed in pytest 7.
See commits e2934c3f8c and
f10ab021e2 for reference.
Didn't call it absolute or absolute_path to avoid conflicts with
possible variable names.
Didn't call it abspath to avoid confusion with os.path.abspath.
This makes mypy raise an error whenever it detects code which is
statically unreachable, e.g.
x: int
if isinstance(x, str):
... # Statement is unreachable [unreachable]
This is really neat and finds quite a few logic and typing bugs.
Sometimes the code is intentionally unreachable in terms of types, e.g.
raising TypeError when a function is given an argument with a wrong
type. In these cases a `type: ignore[unreachable]` is needed, but I
think it's a nice code hint.
This prevents referring to a generic type without filling in its generic
type parameters.
The FixtureDef typing might need some more refining in the future.
In Python, if module A defines a name `name`, and module B does `import
name from A`, then another module C can `import name from B`.
Sometimes it is intentional -- module B is meant to "reexport" `name`.
But sometimes it is just confusion/inconsistency on where `name` should
be imported from.
mypy has a flag `--no-implicit-reexport` which puts some order into
this. A name can only be imported from a module if
1. The module defines the name
2. The module's `__all__` includes the name
3. The module imports the name as `from ... import .. as name`.
This flag is included in mypy's `--strict` flag.
I like this flag, but I realize it is a bit controversial, and in
particular item 3 above is a bit unfriendly to contributors who don't
know about it. So I didn't intend to add it to pytest.
But while investigating issue 7589 I came upon mypy issue 8754 which
causes `--no-implicit-reexport` to leak into installed libraries and
causes some unexpected typing differences *in pytest* if the user uses
this flag.
Since the diff mostly makes sense, let's just conform to it.
We barely use it; the couple places that do are not really worth the
extra dependency, I think the code is clearer without it.
Also simplifies one (regular) itertools usage.
Also improves a check and an error message in `pytest.raises`.
Part of the effort to reduce dependency on the py library.
Besides that, py.xml implements its own XML serialization which is
pretty scary.
I tried to keep the code with minimal changes (though it could use some
cleanups). The differences in behavior I have noticed are:
- Attributes in the output are not sorted.
- Some unneeded escaping is no longer performed, for example escaping
`"` to `"` in a text node.
1. Remove sys.maxunicode check & comment. Nowadays it is always a
constant 0x10ffff.
2. Pre-generate the pattern. Possible due to 1.
3. Compile the regex lazily. No reason to pay startup cost for it.
4. Add docstring in particular to explain a subtle point.
`os.scandir()`, introduced in Python 3.5, is much faster than
`os.listdir()`. See https://www.python.org/dev/peps/pep-0471/.
It also has a `DirEntry` which can be used to further reduce syscalls in
some cases.
Part of reducing dependency on `py`. Also enables upcoming improvements.
In cases where there are simpler alternatives (in tests), I used those.
What's left are a couple of uses in `_pytest.main` and `_pytest.python`
and they only have modest requirements, so all of the featureful code
from py is not needed.
The previous typing had an object passed to the user, which they can't
do anything with without asserting, which is inconvenient. Change it to
Any instead.
Note that what comes *back* to pytest (the return value) should be an
`object`, because we want to handle arbitrary objects without assuming
anything about them.
If a test runtest phase (not setup) dynamically adds a pytest.mark.xfail
mark to the item, it should be respected, but it wasn't. This regressed
in 3e6fe92b7e (not released).
Fix it by just always refreshing the mark if needed. This is mostly what
was done before but in a more roundabout way.
eval() is used for evaluating string conditions in skipif/xfail e.g.
@pytest.mark.skipif("1 == 0")
This is the only code that uses `_pytest._code.compile()`, so removing
its last use enables us to remove it entirely.
In this case it doesn't add much. Plain compile() gives a good enough
error message.
For regular exceptions, the message is the same.
For SyntaxError exceptions, e.g. "1 ==", the previous code adds a little
bit of useful context:
```
invalid syntax (skipping.py:108>, line 1)
The above exception was the direct cause of the following exception:
1 ==
^
(code was compiled probably from here: <0-codegen /pytest/src/_pytest/skipping.py:108>) (line 1)
During handling of the above exception, another exception occurred:
Error evaluating 'skipif' condition
1 ==
^
SyntaxError: invalid syntax
```
The new code loses it:
```
unexpected EOF while parsing (<skipif condition>, line 1)
During handling of the above exception, another exception occurred:
Error evaluating 'skipif' condition
1 ==
^
SyntaxError: invalid syntax
```
Since the old message is a minor improvement to an unlikely error
condition in a deprecated feature, I think it is not worth all the code
that it requires.
This has been there since as far as the git history goes (2007), is not
covered by any test, and says "Buggy python version consider upgrading".
Hopefully everyone have upgraded...
Setting log_level via the CLI or .ini will control the log level of the
report that is dumped upon failure of a test.
If caplog modified the log level during the execution of that test, it
should not impact the level that is displayed upon failure in the
"captured log report" section.
[
ran:
- rebased
- reused handler
- changed store keys also to "caplog_handler_*"
- added changelog
all bugs are mine :)
]
There is no need to do the XPASS check here, pytest_runtest_makereport
already handled that (the current handling there is dead code).
All the hook needs to do is refresh the xfail evaluation if needed, and
check the NOTRUN condition again.
Previously, skipif/xfail marks were evaluated using a `MarkEvaluator`
class. I found this class very difficult to understand.
Instead of `MarkEvaluator`, rewrite using straight functions which are
hopefully easier to follow.
I tried to keep the semantics exactly as before, except improving a few
error messages.
This type was actually in `_pytest.skipping` previously, but was moved to
`_pytest.mark.evaluate` in cf40c0743c.
I think the previous location was more appropriate, because the
`MarkEvaluator` is not a generic mark facility, it is explicitly and
exclusively used by the `skipif` and `xfail` marks to evaluate their
particular set of arguments. So it is better to put it in the plugin
code.
Putting `skipping` related functionality into the core `_pytest.mark`
module also causes some import cycles which we can avoid.
`@pytest.mark.xfail` is meant to work with arbitrary items, and there is
a test `test_mark_xfail_item` which verifies this.
However, the code for some reason uses `pytest_pyfunc_call` for the
call phase check, which only works for Function items. The test
mentioned above only passed "accidentally" because the
`pytest_runtest_makereport` hook also runs a `evalxfail.istrue()` which
triggers and evaluation, but conceptually it shouldn't do that.
Change to `pytest_runtest_call` to make the xfail checking properly
generic.
While working on improving the documentation of the
`pytest_runtest_setup` hook, I came up with this text:
> Called to perform the setup phase of the test item.
>
> The default implementation runs ``setup()`` on item and all of its
> parents (which haven't been setup yet). This includes obtaining the
> values of fixtures required by the item (which haven't been obtained
> yet).
But upon closer inspection I noticed this line at the start of
`SetupState.prepare` (which is what does the actual work for
`pytest_runtest_setup`):
self._teardown_towards(needed_collectors)
which implies that the setup phase of one item might trigger teardowns
of *previous* items. This complicates the simple explanation. It also
seems like a completely undesirable thing to do, because it breaks
isolation between tests -- e.g. a failed teardown of one item shouldn't
cause the failure of some other items just because it happens to run
after it.
So the first thing I tried was to remove that line and see if anything
breaks -- nothing did. At least pytest's own test suite runs fine. So
maybe it's just dead code?
This option checks even functions which are not annotated. It's a good
step to ensure that existing type annotation are correct.
In a Pareto fashion, the last few holdouts are always the ugliest,
beware.
The FixtureFunctionMarker attrs class already converts the params
itself.
When adding types, the previous converter composition causes some type
error, but extracting it to a standalone function fixes the issue (a
lambda is not supported by the mypy plugin, currently).
There are state transitions start/done/suspend/resume and two additional
operations snap/writeorg.
Previously it was not well defined in what order they can be called, and
which operations are idempotent.
Formalize this and enforce using assert checks with informative error
messages if they fail (rather than random AttributeErrors).
Make it easier to read the file in progression, and avoid forward
references for upcoming type annotations.
There is one cycle, CaptureManager <-> CaptureFixture, which is hard to
untangle.
(This commit should be added to `.gitblameignore`).
`TerminalWriter`, imported recently from `py`, contains its own
incomplete wcwidth (`char_with`/`get_line_width`) implementation. The
`TerminalReporter` also needs this, but uses the external `wcwidth`
package.
This commit brings the `TerminalWriter` implementation up-to-par with
`wcwidth`, moves to implementation to a new file `_pytest._io.wcwidth`
which is used everywhere, and removes the dependency.
The differences compared to the `wcwidth` package are:
- Normalizes the string before counting.
- Uses Python's `unicodedata` instead of vendored Unicode tables. This
means the data corresponds to the Python's version Unicode version
instead of the `wcwidth`'s package version.
- Apply some optimizations.
pytest.fixture() can be used either as
@pytest.fixture
def func(): ...
or as
@pytest.fixture()
def func(): ...
or (while maybe not intended)
func = pytest.fixture(func)
so it needs to inspect internally whether it got a function in the first
positional argument or not.
Previously, there were was oddity. In the following,
func = pytest.fixture(func, autouse=True)
# OR
func = pytest.fixture(func, parms=['a', 'b'])
The result is as if `func` wasn't passed.
There isn't any reason for this special that I can understand, so remove
it.
_pytest.timing is an indirection to 'time' functions, which pytest production
code should use instead of 'time' directly.
'mock_timing' is a new fixture which then mocks those functions, allowing us
to write time-reliable tests which run instantly and are not flaky.
This was triggered by recent flaky junitxml tests on Windows related to timing
issues.
This is already done in pytest_runtest_logstart, so the fspath is
already guaranteed to have been printed (for xdist, it is disabled
anyway).
write_fspath_result is mildly expensive so it is worth avoiding calling
it twice.
The `FDCapture`/`FDCaptureBinary` classes, used by `capfd`/`capfdbinary`
fixtures and the `--capture=fd` option (set by default), redirect FDs
1/2 (stdout/stderr) to a temporary file. To do this, they need to save
the old file by duplicating the FD before redirecting it, to be restored
once finished.
Previously, if this duplicating (`os.dup()`) failed, most likely due to
that FD being invalid, the FD redirection would silently not be done. The
FD capturing also performs python-level redirection (monkeypatching
`sys.stdout`/`sys.stderr`) which would still be done, but direct writes
to the FDs would fail.
This is not great. If pytest is run with `--capture=fd`, or a test is
using `capfd`, it expects writes to the FD to work and be captured,
regardless of external circumstances.
So, instead of disabling FD capturing, keep the redirection to a
temporary file, just don't restore it after closing, because there is
nothing to restore to.
This makes a difference for e.g. pytest-xdist:
Before:
```
--dist=distmode set mode for distributing tests to exec environments. each: …
available environment. loadscope: …
grouped by file to any available environment. (default) no: …
```
After:
```
--dist=distmode set mode for distributing tests to exec environments.
each: send each test to all available environments.
load: load balance by sending any pending test to any available environment.
…
(default) no: run tests inprocess, don't distribute.
```
This might also result in unexpected changes (hard wrapping), when line
endings where used unintentionally, e.g. with:
```
help="""
some long
help text
"""
```
But the benefits from that are worth it, and it is easy to fix, as will
be done for the internal `assertmode` option.
Currently, a bad logging call, e.g.
logger.info('oops', 'first', 2)
triggers the default logging handling, which is printing an error to
stderr but otherwise continuing.
For regular programs this behavior makes sense, a bad log message
shouldn't take down the program. But during tests, it is better not to
skip over such mistakes, but propagate them to the user.
Previously, a LoggingCaptureHandler was instantiated for each test's
setup/call/teardown which turns out to be expensive.
Instead, only keep one instance and reset it between runs.
The logstart/logreport/logfinish hooks don't need the stuff in
_runtest_for. The test capturing catching_logs call is irrelevant for
them, and the item-conditional sections are gone.
- Instead of making it optional, always set up a handler, but possibly
going to /dev/null. This simplifies the code by removing a lot of
conditionals. It also can replace the NullHandler() we already add.
- Change `set_log_path` to just change the stream, instead of recreating
one. Besides plugging a resource leak, it enables the next item.
- Remove the capturing_logs from _runtest_for, since it sufficiently
covered by the one in pytest_runtestloop now, which wraps all other
_runtest_for calls.
The first item alone would have had an adverse performance impact, but
the last item removes it.
Remove usage of `@contextmanager` as it is a bit slower than
hand-rolling, and also disallows re-entry which we want to use.
Removing protections around addHandler()/removeHandler(), because
logging already checks that internally.
Conceptually it doesn't check per catching_logs (and catching_logs
doesn't restore the older one either). It is just something that is
defined for each handler once.
The default message is often hard to read:
E _pytest.config.ConftestImportFailure: (local('D:\\projects\\pytest\\.tmp\\root\\foo\\conftest.py'), (<class 'RuntimeError'>, RuntimeError('some error',), <traceback object at 0x000001CCC3E39348>))
Using a shorter message is better:
E _pytest.config.ConftestImportFailure: RuntimeError: some error (from D:\projects\pytest\.tmp\root\foo\conftest.py)
And we don't really lose any information due to exception chaining.
This removes the KeyError from the traceback chain when an
conftest fails to import:
return self._conftestpath2mod[key]
E KeyError: WindowsPath('D:/projects/pytest/.tmp/root/foo/conftest.py')
During handling of the above exception, another exception occurred:
...
raise RuntimeError("some error")
E RuntimeError: some error
During handling of the above exception, another exception occurred:
...
E _pytest.config.ConftestImportFailure: (...)
By slightly changing the code, we can remove the first chain, which is often
very confusing to users and doesn't help with anything.
Fix#7223
Only filter with known failures, and explicitly keep paths of passed
arguments.
This also displays the "run-last-failure" status before collected files,
and does not update the cache with "--collect-only".
Fixes https://github.com/pytest-dev/pytest/issues/6968.
The previous commit made this possible, so utilize it.
Since legacy.py becomes pretty bare, I inlined it into __init__.py. I'm
not sure it's really "legacy" anyway!
Using a simple 50000 items benchmark with `--collect-only -k nomatch`:
Before (two commits ago):
======================== 50000 deselected in 10.31s =====================
19129345 function calls (18275596 primitive calls) in 10.634 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.001 0.001 2.270 2.270 __init__.py:149(pytest_collection_modifyitems)
1 0.036 0.036 2.270 2.270 __init__.py:104(deselect_by_keyword)
50000 0.055 0.000 2.226 0.000 legacy.py:87(matchkeyword)
After:
======================== 50000 deselected in 9.37s =========================
18029363 function calls (17175972 primitive calls) in 9.701 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 1.394 1.394 __init__.py:239(pytest_collection_modifyitems)
1 0.057 0.057 1.393 1.393 __init__.py:162(deselect_by_keyword)
The matching itself can be optimized more but that's a different story.
In current pytest, the same expression is matched against all items. But
it is re-parsed for every match.
Add support for "compiling" an expression and reusing the result. Errors
may only occur during compilation.
This is done by parsing the expression into a Python `ast.Expression`,
then `compile()`ing it into a code object. Evaluation is then done using
`eval()`.
Note: historically we used to use `eval` directly on the user input --
this is not the case here, the expression is entirely under our control
according to our grammar, we just JIT-compile it to Python as a
(completely safe) optimization.
The `-k '-expr'` syntax is an old alias to `-k 'not expr'`. It's also
not a very convenient to have syntax that start with `-` on the CLI.
Deprecate it and suggest replacing with `not`.
---
The `-k 'expr:'` syntax discards all items until the first match and
keeps all subsequent, e.g. `-k foo` with
test_bar
test_foo
test_baz
results in `test_foo`, `test_baz`. That's a bit weird, so deprecate it
without a replacement. If someone complains we can reconsider or devise
a better alternative.
Running `pytest | head -1` and similar causes an annoying error to be
printed to stderr:
Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>
BrokenPipeError: [Errno 32] Broken pipe
(or possibly even a propagating exception in older/other Python versions).
The standard UNIX behavior is to handle the EPIPE silently. To
recommended method to do this in Python is described here:
https://docs.python.org/3/library/signal.html#note-on-sigpipe
It is not appropriate to apply this recommendation to `pytest.main()`,
which is used programmatically for in-process runs. Hence, change
pytest's entrypoint to a new `pytest.console_main()` function, to be
used exclusively by pytest's CLI, and add the SIGPIPE code there.
Fixes#4375.
When setting up the warnings capture, filter strings (with the general
form `action:message:category:module:line`) are collected from the
cmdline, ini and item and applied. This happens for every test and other
cases.
To apply a string it needs to be parsed into a tuple, and it turns out
this is slow. Since we already vendor the parsing code from Python's
warnings.py, we can speed it up by caching the result. After splitting
the parsing part from the applying part, the parsing is pure and is
straightforward to cache.
An alternative is to parse ahead of time and reuse the result, however
the caching solution turns out cleaner and more general in this case.
On this benchmark:
import pytest
@pytest.mark.parametrize("x", range(5000))
def test_foo(x): pass
Before:
============================ 5000 passed in 14.11s =============================
14365646 function calls (13450775 primitive calls) in 14.536 seconds
After:
============================ 5000 passed in 13.61s =============================
13290372 function calls (12375498 primitive calls) in 14.034 seconds
- replace "tests with warnings" with just warnings: they a) might not
come from a test in the first place, and b) a single test might have
multiple warnings.
- fix usage of (unused) argument to `collapsed_location_report`
Co-authored-by: Ran Benita <ran@unusedvar.com>
Move {Passthrough,CaptureIO} to capture module, and rename Passthrough
-> Tee to match the existing terminology.
Co-authored-by: Ran Benita <ran@unusedvar.com>
Also delay calling tearDown() when --pdb is given, so users still have
access to the instance variables (which are usually cleaned up during tearDown())
when debugging.
Fix#6947
Instead of trying to handle unittest-async functions in pytest_pyfunc_call,
let the unittest framework handle them instead.
This lets us remove the hack in pytest_pyfunc_call, with the upside that
we should support any unittest-async based framework.
Also included 'asynctest' as test dependency for py37-twisted, and renamed
'twisted' to 'unittestextras' to better reflect that we install 'twisted' and
'asynctest' now.
This also fixes the problem of cleanUp functions not being properly called
for async functions.
Fix#7110Fix#6924
Previously, the expressions given to the `-m` and `-k` options were
evaluated with `eval`. This causes a few issues:
- Python keywords cannot be used.
- Constants like numbers, None, True, False are not handled correctly.
- Various syntax like numeric operators and `X if Y else Z` is supported
unintentionally.
- `eval()` is somewhat dangerous for arbitrary input.
- Can fail in many ways so requires `except Exception`.
The format we want to support is quite simple, so change to a custom
parser. This fixes the issues above, and gives us full control of the
format, so can be documented comprehensively and even be extended in the
future if we wish.
Currently this property is computed eagerly, which means
get_line_width() is computed on everything written, but that is a slow
function.
Compute it lazily, so that get_line_width() only runs when needed.
Flushing on every write is somewhat expensive.
Rely on line buffering instead (if line buffering for stdout is
disabled, there must be some reason...), and add explicit flushes when
not outputting lines.
This is how regular `print()` e.g. work so should be familiar.
Anthony Sottile
Ran Benita
Jakob van Santen
Sorin Sbarnea
Florian Bruhin
Bruno Oliveira
Maximilian Cosmo Sitter
hp310780
Zac Hatfield-Dodds
Lewis Cowles
Simon K
Hugo van Kemenade
Arvin Firouzi
Vlad-Radz
Gleb Nikonorov
Ruaridh Williamson
gdhameeja
Lukas Geiger
David Diaz Barquero
Ram Rachum
Andrew
Ronny Pfannschmidt
Zac-HD
ibriquem
piotrhm
Prashant Anand
Fabio Zadrozny
Tor Colvin
Keri Volans
Daniel Hahler
Katarzyna Król
Florian Dahlitz
Claire Cecil
Daniel Hahler
Felix Nieuwenhuizen
Pavel Karateev
Katarzyna