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...compilers was still an issue in 1996, and because I considered the benefits of C++ for the small amount of compiled code in the project insufficient to compensate for the complexity of the language. Library architecture The architecture of MMTK is clearly Python-driven. To the user, it presents itself as a pure Python library. The C code in MMTK was written from scratch in the form of Python extension modules that only handle the few time-critical aspects: evaluation of interaction energies, a...
...compiler currently inserts a 4 padding bytes; with the change, these padding bytes become part of the size. in strings, the ob_shash field follows ob_size. This field is of type long, which is a 64-bit type on most 64-bit systems (except Win64), so the compiler inserts padding before it as well. Open Issues Marc-Andre Lemburg commented that complete backwards compatibility with existing source code should be preserved. In particular, functions that have Py_ssize_t* output arguments should c...
...compiler toolchains that most developers use to do their daily work are incapable of building manylinux1-compliant wheels. Therefore, we do not attempt to change the default behavior of pip wheel / bdist_wheel: they will continue to generate regular linux_* platform tags, and developers who wish to use them to generate manylinux1-tagged wheels will have to change the tag as a second post-processing step. To support the compilation of wheels meeting the manylinux1 standard, we provide initial dra...
...compiler to decide if function should be inlined or not. ./configure --with-pydebug uses the -Og compiler option if it's supported by the compiler (GCC and LLVM Clang support it): optimize debugging experience. Otherwise, the -O0 compiler option is used: disable most optimizations. With GCC 11, gcc -Og can inline static inline functions, whereas gcc -O0 does not inline static inline functions. Examples: Call Py_INCREF() in PyBool_FromLong(): gcc -Og: inlined gcc -O0: not inlined, call Py_INCREF...
...compiler, and there's nothing to stop crooked code from modifying its value. Option 1 The most limiting option is to freeze the dict in the compiler. This would require that the case expressions are all literals or compile-time expressions involving only literals and operators whose semantics are known to the compiler, since with the current state of Python's dynamic semantics and single-module compilation, there is no hope for the compiler to know with sufficient certainty the values of any v...
Python Distutils-SIG: Proposed User Interface Python Distutils-SIG Proposed User Interface In addition to identifying the common tasks and division of labour involved in developing, distributing, and installing Python modules, the "Extension Building Considered Painful" Developer's Day Session also came up with a proposed user interface. The core idea of the interface is that the module developer would provide a small Python script, called setup.py ...
...compiler-sig Jeremy Hylton Compiling and parsing Python Type checking, code generation archive May 2001 do-sig David Arnold Distributed Object Technologies archive August 2002 getopt-sig Greg Ward Argument parsing SIG archive February 2003 parser-sig A.M. Kuchling Parsing archive February 2003 persistence-sig Jeremy Hylton Persistence Framework for Python archive September 2003 plot-sig David Ascher Plotting and Graphing archive May 2001 thread-sig Greg Stein Process Threading archive May ...
...compiler? There are multiple JIT compilers for Python actively developed: PyPy Pyston Numba Pyjion Numba is specific to numerical computation. Pyston and Pyjion are still young. PyPy is the most complete Python interpreter, it is generally faster than CPython in micro- and many macro-benchmarks and has a very good compatibility with CPython (it respects the Python semantics). There are still issues with Python JIT compilers which avoid them to be widely used instead of CPython. Many popular ...
...compiler combo will need to be updated to work as follows: read the file decode it into Unicode assuming a fixed per-file encoding convert it into a UTF-8 byte string tokenize the UTF-8 content compile it, creating Unicode objects from the given Unicode data and creating string objects from the Unicode literal data by first reencoding the UTF-8 data into 8-bit string data using the given file encoding Note that Python identifiers are restricted to the ASCII subset of the encoding, and thus n...
...compiler for Python. Quirks There are just two quirks that affected our development with Python. The relative impact they had on our project was tiny compared to Python's benefits but for balance we feel they are worth mentioning: 1) Like Java and other languages, Python occasionally deprecates old features, or fixes minor bugs in a way that can potentially break existing code. This is done over the course of a number of releases, so that programmers will first see deprecation warnings, and o...
...compiler into a situation in which they need to know how to separate valid programs from invalid programs, which should be a responsibility solely of the parser. This also leads to the actual grammar file not reflecting correctly what the actual grammar is (that is, the collection of all valid Python programs). Similar workarounds appear in multiple other rules of the current grammar. Sometimes this problem is unsolvable. For instance, bpo-12782: Multiple context expressions do not support paren...
...Compiler A new ASDL expression type Starred is added which represents a starred expression. Note that the starred expression element introduced here is universal and could later be used for other purposes in non-assignment context, such as the yield *iterable proposal. The compiler is changed to recognize all cases where a starred expression is invalid and flag them with syntax errors. A new bytecode instruction, UNPACK_EX, is added, whose argument has the number of mandatory targets before the...
...compilers did not have any problems with this code. However, modern compilers use that clause as an optimization opportunity, finding that f->ob_refcnt and o->ob_refcnt cannot possibly refer to the same memory, and that therefore the function should return 0, without having to fetch the value of ob_refcnt at all in the return statement. For GCC, Python now uses -fno-strict-aliasing to work around that problem; with other compilers, it may just see undefined behavior. Even with GCC, using -...
...compiler may define as many "kinds" of integer and floating point numbers as it likes, except that it must support at least two kinds of integer corresponding to the existing int and long, and must support at least one kind of floating point number, equivalent to the present float. The range and precision of these required kinds are processor dependent, as at present, except for the "long integer" kind, which can hold an arbitrary integer. The built-in functions int(), long(), and float() conver...
...compiler-specific extensions, such as those of GCC or MSVC (e.g. don't write multi-line strings without trailing backslashes). All function declarations and definitions must use full prototypes (i.e. specify the types of all arguments). No compiler warnings with major compilers (gcc, VC++, a few others). static inline functions should be preferred over macros in new code. Code lay-out Use 4-space indents and no tabs at all. No line should be longer than 79 characters. If this and the previ...
...Compiler-SIG http://www.python.org/sigs/compiler-sig/ [2]Parser Module Documentation http://docs.python.org/library/parser.html [3]Hylton, Jeremy. http://docs.python.org/library/compiler.html [4]Pelletier, Michel. "Python Interface Syntax", PEP 245 [5]The Python Types-SIG http://www.python.org/sigs/types-sig/ Copyright This document has been placed in the public domain. Source: https://github.com/python/peps/blob/master/pep-0269.txt
...compiler to detect an if-elif-else construct which has the following signature: if x == 'first':... elif x == 'second':... else:... i.e. the left hand side always references the same variable, the right hand side a hashable immutable builtin type. The right hand sides need not be all of the same type, but they should be comparable to the type of the left hand switch variable. The compiler could then setup a read-only (perfect) hash table, store it in the constants and add an opcode SWITCH in ...
...compiler. As a recommendation, a specific ABI is recommended for selected platforms. During evolution of Python, new ABI functions will be added. Applications using them will then have a requirement on a minimum version of Python; this PEP provides no mechanism for such applications to fall back when the Python library is too old. Terminology Applications and extension modules that want to use this ABI are collectively referred to as "applications" from here on. Header Files and Preprocessor ...
...compiler now converts the source code to an abstract syntax tree (AST) before producing the bytecode. The 'with' operator replaces a common try/finally idiom that results in much cleaner and safer code. Generators gained send, throw and close methods. Values passed to send will be returned by the yield statement when the generator is resumed. throw takes an exception and causes the yield statement to raise the passed exception in the generator. close is used to terminate a generator. This turns ...
...compiler maintains two scopes: one for the normal class body code, and one for annotations. (This is facilitated by four new functions: compiler.c adds compiler_push_scope() and compiler_pop_scope(), and symtable.c adds symtable_push_scope() and symtable_pop_scope().) Once the code generator reaches the end of the class body, but before it generates the bytecode for the class body, it assembles the bytecode for __co_annotations__, then assigns that to __co_annotations__ using STORE_NAME. It also...