CHANGELOG.md

Python Changelog

This changelog summarizes major changes between GraalVM versions of the Python language runtime. The main focus is on user-observable behavior of the engine.

Version 21.0.0

• Implement name mangling for private attributes
• Correctly raise an AttributeError when a class defines slots, but not dict
• Fix infinite continuation prompt in REPL when pasting snippets
• Add jarray module for compatiblity with Jython
• Fix multiple memory leaks and crashes when running NumPy in a shared engine
• Improved support for Pandas
• Initial support for Matplotlib
• Many fixes to pass the unittests of standard library types and modules: abc, array, builtin, bzip2, decimal, descriptors, difflib, enum, fractions, gzip, memoryview, metaclass, pickle, platform, print, reprlib, statistics, strftime, strtod, sysconfig, userdict, userlist, userstring, zipfile, zipfile64, zlib
• Improve performance in multiple areas: array, memoryview, unzipping packages, dictionaries with dynamic string keys, string slicing

Version 20.3.0

• Fix multiple memory leaks when running Python code in a shared engine.
• Update language support target and standard library to 3.8.5
• Hide internal catching frames from tracebacks
• Update HPy support to the latest version with support for piconumpy
• Many fixes to pass the unittests of standard library types and modules: complex, bytes, bytearray, subclassing of special descriptors, type layouts, float, generators, modules, argument passing corner cases, string literals and encodings, import and importlib, decimal, glob, the builtin module, json, math, operator, numeric tower, sys, warnings, random, f-strings, struct, itertools

Version 20.2.0

• Escaping Unicode characters using the character names in strings like "\N{GREEK CAPITAL LETTER DELTA}".
• When a *.py file is imported, *.pyc file is created. It contains binary data to speed up parsing.
• Adding option PyCachePrefix, which is equivalent to PYTHONPYCACHEPREFIX environment variable, which is also accepted now.
• Adding optin DontWriteBytecodeFlag. Equivalent to the Python -B flag. Don't write bytecode files.
• Command option -B works
• Implement better reference counting for native extensions to fix memory leaks
• Fix a warning in pandas about size of datetime objects
• Make many more CPython unittests pass for core types
• Support parse requests with arguments for embedding Python to light up GraalVM Insight support
• Support basic tox usage when forcing virtualenv to use venv
• No longer support iterables as arrays in interop
• Add initial support for HPy native extensions
• Support magic encoding comments in Python files
• Improve chaining of exception tracebacks - the tracebacks should now be much closer to CPython and more helpful

Version 20.1.0

• Update language support target and standard library to 3.8.2
• Improve performance of tuples with primitive elements
• Improve performance of using Python sequences from other GraalVM languages
• Improve performance of dictionaries and sets
• Improve performance of allocations for list comprehensions with range iterators
• Support cProfile and trace modules through the GraalVM CPU sampler and coverage, respectively
• Support NumPy on macOS
• Support setuptools-scm and pytz.timezone
• Support new syntax for iterable unpacking from yield and return statements
• Fix issues with inspection and printing of non-Python numbers in the Chrome debugger
• Fix issues with AST sharing across different contexts, if these context run concurrently on multiple threads
• Fix code serialization and deserialization with pickle
• Fix DirEntry.stat
• Fix passing non-ASCII strings to gethostbyname
• Fix help(numpy) to work again in the interactive REPL
• Fix multi-line continuation in the REPL for opening parens
• Fix select.select for pipes
• Polyglot: Rethrow AttributeError as UnknownIdentifierException in invokeMember
• Jython mode: treat Java null as identical to Python None when comparing with the is operator
• Jython mode: isinstance now works with Java classes and objects
• Improve errno handling in posix module
• Move all GraalPython specific functions on sys or builtins to the __graalpython__ module

Version 20.0.0

• Jython Compatiblity: Implement from JavaType import * to import all static members of a Java class
• Jython Compatiblity: Implement importing Python code from inside JAR files by adding path/to/jarfile.jar!path/inside/jar to sys.path
• Added support for date and time interop.
• Added support for setting the time zone via Context.Builder.timeZone.
• PEP 570 - Python Positional-Only Parameters implemented

Version 19.3.0

• Implement gc.{enable,disable,isenabled} as stubs
• Implement charmap_build function
• Implement hexversion in sys module
• Implement _lzma module
• Implement enough of socket.socket to run graalpython -m http.server and download non-encrypted http resources
• Fix printing of Pandas data frames
• Fix a bug in bytes.startswith for tuple arguments
• Fix destructuring assignments of arbitrary iterators
• Fix dict.__contains__ for dictionaries with only str keys for subclasses of str
• Support NumPy 1.16.4 and Pandas 0.25.0
• Support timeit module
• Support basic usage of pytest
• Improve performance across many Python and C extension benchmarks
• Improve performance of our parser
• Improve performance of catching exceptions when the exception does not leave the handler block and the traceback is not accessed
• Improve performance of Java interop when Python objects are accessed from Java
• Add a new --python.EmulateJython flag to support importing Java classes using normal Python import syntax and to catch Java exceptions from Python code
• Update standard library to Python 3.7.4
• Initial implementatin of PEP 498 -- Literal String Interpolation

Version 19.2.0

• Implement PyStructSequence_* C API functions
• Implement _functools.partial as a class instead of a function
• Implement type.__base__
• Implement reading C API type attributes nb_inplace_add, nb_remainder, nb_subtract, and nb_floor_divide for builtin types
• Implement C API functions _PyObject_CallFunction_SizeT, PyEval_InitThreads, and PyEval_ThreadsInitialized
• Implement writing to a function's __dict__ field
• Implement the C API thread state fields overflowed and recursion_depth
• Fix printing of errors in the REPL
• Fix printing full paths in traceback
• Support the C API varargs functions with arbitrary numbers of arguments instead of imposing an upper limit
• Improve performance of attribute reads and reading closure variables

Version 19.1.0

• Add java.add_to_classpath API to dynamically extend the host class path
• Allow write access to main module bindings for embedder
• Swap arguments for polyglot.export_value to use the more natural (name, value) order and deprecate the previous argument order.
• Update Python standard library files to Python 3.7.3
• Improve performance of exceptions that do not escape
• Fix str(None) to print "None" instead of an empty string
• Fix error messages on polyglot objects to not leak implementation class names of those objects
• Fix erroneously frozen package paths in pre-initialized python modules
• Fix caching of core sources in a native image with a preinitialized context for pre-built images and libpolyglot fast startup
• Implement pwd.getpwuid
• Implement os.exec, os.execv, and os.execl
• Add some missing C API headers needed for tensorflow compilation

Version 19.0.0

• Fix an issue preventing use of encodings in the installable binary
• Fix return value of process when os.exit is called with a boolean
• Fix interpretation of foreign objects to prefer interpreting them as integer over double
• Fix performance regression when repeatedly creating a new function in a loop

Version 1.0.0 RC16

• No user-facing changes

Version 1.0.0 RC15

• Implement PEP 487 __init_subclass__
• Implement PEP 560 __class_getitem__ and __mro_entries__
• Migrate to Truffle libraries for interop
• Support the buffer protocol for mmap
• Support importing java classes using normal Python import syntax
• Improve performance of literal dictionary creation when the first but not all keys are strings
• Improve performance of getting the length of a string
• Improve performance of accessing defaults, keyword-defaults, and code of a function
• Fix getting file separator from the Truffle filesystem rather than the operating system
• Fix constructing and calling methods with non-function callables
• Fix execution of subprocesses with non-default python homes on JVM

Version 1.0.0 RC14

• Mark a subset of the Graal Python launcher options as "stable". All other options are subject to change and need to be unlocked explicitly on the commandline.
• Automatically install pip when creating a venv. The socket and ssl libraries are still not functional, so pip can only install from local sources or wheels.
• Update the standard library to Python 3.7.0 from 3.6.5.
• Support the -I flag to ignore the user environment and not add the working directory to sys.path
• Fix an error preventing usage of the memtracer tool. If an object raised an exception in it's __repr__ method, it would abort the execution.
• Fix issues around not being able to modify function defaults, keyword defaults, or re-defining a function with a different closure.
• Fix continuation prompt in the interactive Python shell when an incomplete statement was typed. Before it raised and ignored a SyntaxError.
• Fix frame restarting of Python functions in the Chrome debugger. Before, functions with closures would have their cells accidentally cleared.

Version 1.0.0 RC13

• Support marshal.dumps and marshal.loads for code objects and some other built-in objects
• Fix installation of NumPy in a venv
• Initial support for module mmap
• Support debugging with workspace files in the Chrome debugger
• Support the PEP 553 breakpoint() message
• Support running weak reference callbacks and signals on the main thread

Version 1.0.0 RC12

• Support the __class__ variable in the class scope
• Support module-level docstrings
• Initial support for the venv standard-library tool
• Initial support for the built-in _bz2 module
• Initial support for the pandas package
• Initial support for OSError subclasses based on the errno of the exception
• Fix bytearray inplace add to return the same object
• Fix access to standard Python methods (__repr__, __str__, __len__ and the like) for foreign objects

Version 1.0.0 RC11

• Support running setuptools to build and install various packages
• Support running a source release version of NumPy out of the box
• Improve performance of member access to C API objects
• Improve performance of binary operations on C API objects
• Add support for yield from
• Support assignment to object.__dict__ and ensure that managed subclasses of native types also have a __dict__
• Fix [] access with non-integer keys for array-like foreign objects
• Fix various performance regressions introduced in the last RC
• Implement more built-in methods on the time module
• Python no longer exposes internal languages through polyglot.eval
• Improve performance of os.scandir and functions that build on it (such as glob)
• More correct implementation of standard streams, including buffering
• Properly support the -m switch to run modules
• Support the standard zipfile module
• Add the built-in _cvs module
• Add support for __slots__
• Allow arbitrary callable objects in methods, not only functions
• Report that we have a TTY console if we are launched on a Terminal through our launcher
• Add the ginstall custom module to install known packages such as NumPy and setuptools

Version 1.0.0 RC10

• Improve performance of C API upcalls
• Improve performance of classmethods, staticmethods, globals(), and locals()
• Improve performance of various string and bytes operations
• Initial support for the _thread builtin module (actual multi-threading is still disabled, the API defaults to a dummy implementation)
• Implement the zipimporter module
• Support assignment to object.__class__
• Use the new Truffle filesystem API to get/set the current working directory
• Attempt our best to report side-effects in KEY_INFO
• The KEYS message now responds with attributes and methods, never dict keys
• Support the input builtin
• Add DEBUG launcher options for performance debugging
• Ensure context isolation for file descriptors and child PIDs
• Fix passing custom locals and globals through exec and eval
• Fixes to builtin help

Version 1.0.0 RC9

• Support help in the builtin Python shell
• Add readline to enable history and autocompletion in the Python shell
• Add support for the -q, -E, -s, and -S Python launcher flags
• Improve display of foreign array-like objects
• Improve support for string and bytes regular expressions using our TRegex engine
• Support loading site-packages installed with easy_install
• Initial support for the binascii module

Version 1.0.0 RC8

• Report allocations when the --memtracer option is used
• Initial support for pickle module

Version 1.0.0 RC7

• Enhance the java interop builtin module with introspection utility methods

Version 1.0.0 RC6

• Support regular expression patterns built from bytes by using CPython's sre module as a fallback engine to our own
• Support LLVM 5+ for C extension modules
• Introduce native sequence storage so that e.g. Python bytes exposed to C can be mutated
• Introduce lazy string concatenation to significantly speed up benchmarks where strings are concatenated repeatedly
• C-API improvements to support more scikit-learn code
• Fix our distinction between builtin functions, functions, and methods to make the classes for builtin functions equivalent to CPython
• Improve set, frozenset, and dict support
• Attach Python exceptions as cause to ImportErrors raised for C extension modules
• Update standard library to CPython 3.6.5
• Support more code object attributes
• Support constant type ids for objects that are interned on CPython
• Add collections.deque
• Document how to contribute
• Improve efficiency of generators
• Enable re-use of ASTs in multiple Contexts in the same Engine

Version 1.0.0 RC5

• Generator expressions now properly evaluate their first iterator in the definition scope at definition time
• Fixes for embedders to ensure top scopes are stable and local scopes always contain TruffleObjects
• C-API improvements to support simple Cython modules
• Support recognition of Python source files with the polyglot launcher

Version 1.0.0 RC4

• No changes

Version 1.0.0 RC3

• Support for more String encodings
• Implement buffered I/O
• Remove our random module substitute and use the standard library implementation
• Fix a potential thread-safety problem with cached parse trees when multiple Python contexts are used from multiple threads
• Complete support for math module builtins
• C-API improvements to run simple scikit-learn and NumPy examples
• Support the buffer protocol to wrap arbitrary Python sequences with no copy into NumPy arrays

Version 1.0.0 RC2

• Updates to the polyglot and embedding APIs
• Many additions to the language core implementation
• Performance improvements to the parser
• C-API improvements to compile and run simple C extensions
• Support breakpoints on caught and uncaught exceptions in debugger

Version 1.0.0 RC1

• LICENSE set to The Universal Permissive License (UPL), Version 1.0.