PEP-498 allows for conversion specifiers like !r and !s to convert the
expression declared in braces to be passed through repr() and str()
respectively.
This updates the logic that detects the end of the expression to also stop
when it sees "![rs]" that is either at the end of the f-string or before
the ":" indicating the start of the format specifier. The "![rs]" is now
retained in the format string, whereas previously it stayed on the end
of the expression leading to a syntax error.
Previously: `f"{x!y:z}"` --> `"{:z}".format(x!y)`
Now: `f"{x!y:z}"` --> `"{!y:z}".format(x)`
Note that "!a" is not supported by `str.format` as MicroPython has no
`ascii()`, but now this will raise the correct error.
Updated cpydiff and added tests.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Prior to this commit, importing a module that exists but has a syntax error
or some other problem that happens at import time would result in a
potentially-incomplete module object getting added to sys.modules.
Subsequent imports would use that object, resulting in confusing error
messages that hide the root cause of the problem.
This commit fixes that issue by removing the failed module from sys.modules
using the new NLR callback mechanism.
Note that it is still important to add the module to sys.modules while the
import is happening so that we can support circular imports just like
CPython does.
Fixes issue #967.
Signed-off-by: David Grayson <davidegrayson@gmail.com>
This is a partial implementation of PEP 448 to allow unpacking multiple
star args in a function or method call.
This is implemented by changing the emitted bytecodes so that both
positional args and star args are stored as positional args. A bitmap is
added to indicate if an argument at a given position is a positional
argument or a star arg.
In the generated code, this new bitmap takes the place of the old star arg.
It is stored as a small int, so this means only the first N arguments can
be star args where N is the number of bits in a small int.
The runtime is modified to interpret this new bytecode format while still
trying to perform as few memory reallocations as possible.
Signed-off-by: David Lechner <david@pybricks.com>
This implements (most of) the PEP-498 spec for f-strings and is based on
https://github.com/micropython/micropython/pull/4998 by @klardotsh.
It is implemented in the lexer as a syntax translation to `str.format`:
f"{a}" --> "{}".format(a)
It also supports:
f"{a=}" --> "a={}".format(a)
This is done by extracting the arguments into a temporary vstr buffer,
then after the string has been tokenized, the lexer input queue is saved
and the contents of the temporary vstr buffer are injected into the lexer
instead.
There are four main limitations:
- raw f-strings (`fr` or `rf` prefixes) are not supported and will raise
`SyntaxError: raw f-strings are not supported`.
- literal concatenation of f-strings with adjacent strings will fail
"{}" f"{a}" --> "{}{}".format(a) (str.format will incorrectly use
the braces from the non-f-string)
f"{a}" f"{a}" --> "{}".format(a) "{}".format(a) (cannot concatenate)
- PEP-498 requires the full parser to understand the interpolated
argument, however because this entirely runs in the lexer it cannot
resolve nested braces in expressions like
f"{'}'}"
- The !r, !s, and !a conversions are not supported.
Includes tests and cpydiffs.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This test snuck through without proper formatting and is causing CI for
other unrelated changes to fail.
Signed-off-by: David Lechner <david@pybricks.com>
The random module's getrandbits() method didn't give a proper error message
when calling it with a value that was outside of the range of 1-32, which
can lead to confusion using this function (which under CPython can accept
numbers larger than 32). Now instead of simply giving a ValueError it
gives an error message that states that the number of bits is constrained.
Also, since the random module's functions getrandbits() and randint()
differ from CPython, tests have been added to describe these differences.
For getrandbits the relevant documentation is shown and added to the docs.
The same is given for randint method so that the information is more easily
found.
Finally, since the int object lacks the bit_length() method there is a test
for that method also to include within the docs, showing the difference to
CPython.
MicroPython does not store any reference from a function object to the
module it was defined in, but there is a way to use function.__globals__ to
indirectly get the module.
See issue #7259.
Signed-off-by: Damien George <damien@micropython.org>
Array equality is defined as each element being equal but to keep
code size down MicroPython implements a binary comparison. This
can only be used correctly for elements with the same binary layout
though so turn it into an NotImplementedError when comparing types
for which the binary comparison yielded incorrect results: types
with different sizes, and floating point numbers because nan != nan.
This commit adds the errno attribute to exceptions, so code can retrieve
errno codes from an OSError using exc.errno.
The implementation here simply lets `errno` (and the existing `value`)
attributes work on any exception instance (they both alias args[0]). This
is for efficiency and to keep code size down. The pros and cons of this
are:
Pros:
- more compatible with CPython, less difference to document and learn
- OSError().errno will correctly return None, whereas the current way of
doing it via OSError().args[0] will raise an IndexError
- it reduces code size on most bare-metal ports (because they already have
the errno qstr)
- for Python code that uses exc.errno the generated bytecode is 2 bytes
smaller and more efficient to execute (compared with exc.args[0]); so
bytecode loaded to RAM saves 2 bytes RAM for each use of this attribute,
and bytecode that is frozen saves 2 bytes flash/ROM for each use
- it's easier/shorter to type, and saves 2 bytes of space in .py files that
use it (for each use)
Cons:
- increases code size by 4-8 bytes on minimal ports that don't already have
the `errno` qstr
- all exceptions now have .errno and .value attributes (a cpydiff test is
added to address this)
See also #2407.
Signed-off-by: Damien George <damien@micropython.org>
This adds the Python files in the tests/ directory to be formatted with
./tools/codeformat.py. The basics/ subdirectory is excluded for now so we
aren't changing too much at once.
In a few places `# fmt: off`/`# fmt: on` was used where the code had
special formatting for readability or where the test was actually testing
the specific formatting.
Commit e269cabe3e added a check that the
first argument to the to_bytes() method is an integer, and now uPy
follows CPython behaviour and raises a TypeError for this test.
Note: CPython checks the argument types before checking the number of
arguments, but uPy does it the other way around, so they give different
exception messages for this test, but still the same type, a TypeError.
Angus Gratton