reticulate 1.41.0

• New py_require() function for declaring Python requirements for
  the current R session. For details, see updated vignettes and help:

  • Installing Python Packages: https://rstudio.github.io/reticulate/dev/articles/python_packages.html
  • Using reticulate in an R Package: https://rstudio.github.io/reticulate/dev/articles/package.html
  • py_require() help: https://rstudio.github.io/reticulate/dev/reference/py_require.html

• New uv_run_tool() function for running command line tools distributed via Python packages.

• Raw R arrays and NumPy arrays with dtype "V1" ("void8") now convert between each other.
  Use r_to_py(as.array(x)) to efficiently convert raw vectors to NumPy arrays, and
  py_to_r(array$view("V1")) to efficiently convert NumPy arrays to raw vectors. (#1734)

• Fixed an issue with using Python 3.12 on Linux (#1712, #1714).

• Fixed an issue where virtualenv_starter() would not discover a
  custom built Python (#1704).

reticulate 1.40.0

• The S3 classes for some (rarely encountered) Python objects have changed.
  Only Python objects with non-standard __module__ values are affected.
  If a Python object’s parent class’s __module__ attribute does not resolve to a string,
  reticulate:

  • Attempts to resolve it from the class's class, if it's a metaclass.
  • If no string can be resolved, reticulate no longer implicitly prepends
    'python.builtin.' as the class prefix, instead it uses just the __name__.
    (See #1686 for more context)

• Added support for Python 3.13. Note that Python 3.13 removed support
  for classmethod descriptors, which may affect the S3 class of
  some Python objects that use metaclass properties to resolve a class’s
  __module__ or __name__ attribute. (#1686, #1698)

• py_is_null_xptr() and [[ now load delayed modules (#1688).

• Fixed error when attempting to use a python venv created with uv (#1678)

• Resolved an issue where py_discover_config() attempted to detect
  Windows App Store Python installations. These are now excluded from
  discovery by both py_discover_config() and virtualenv_starter() (#1656, #1673).

• Fixed an error when converting an empty NumPy char array to R (#1662).

• Fixed an error when using reticulate with radian (#1668, #1670).

• Fixed a segfault encountered when running the Python session finalizer (#1663, #1664).

• Resolved a segfault in RStudio when rapidly switching between
  R and Python chunks in a Quarto document (#1665).

• Improved behavior when the conda binary used to create an environment
  cannot be resolved (contributed by @tl-hbk, #1654, #1659).

• Added Positron support for the Variables Pane and repl_python()
  (#1692, #1641, #1648, #1658, #1681, #1687).

reticulate 1.39.0

• Python background threads can now run in parallel with the R session (#1641).

• py_main_thread_func() is deprecated; every R function can now safely be
  called from background Python threads (#1648).

• Calls from Python threads into R now notify the main thread using R's native
  event loop, ensuring that these calls are handled even when the main thread
  is engaged in non-Python tasks (#1648).

• The knitr engine now avoids overwriting Altair's default chart dimensions with
  the values of ut.width.px and ut.height.px. Use altair.fig.height,
  altair.fig.width, or Altair's width and height parameters to adjust
  chart dimensions (contributed by @joelostblom, #1646).

• New as.character() method for python.builtin.str with support for handling
  embedded NULs in strings (#1653).

• New as.raw() method for python.builtin.bytes (#1649, #1652).

• as.character() method for python.builtin.bytes gains a nul argument,
  allowing for convenient handling of embedded NULs in the string (#1652).

• Reticulate now uses the RETICULATE_VIRTUALENV_ROOT environment variable when
  determining where to resolve virtual environments (#1657).

• conda_run2() is now exported (contributed by @dramanica, #1637).

• The Python session is now finalized when the R session exits (#1648).

• Internal updates for NumPy 2.1 (#1651).

• Fixed error when importing a module named config (#1628).

• Fixes for CRAN check failures on macOS-oldrel (#1645).

• Fixed an error where opening a Python subprocess in Positron on Windows
  resulted in "OSError: [WinError 6] The handle is invalid."
  (#1658, posit-dev/positron#4457).

reticulate 1.38.0

• Python Exceptions converted to R conditions are now R lists instead
  of R environments, for compatability with {rlang} and {purrr}.
  (tidyverse/purrr#1104, r-lib/rlang#1664, #1617)

• Internal updates for NumPy 2.0 (#1621)

• Added support for converting NumPy StringDType arrays to R character arrays. (#1623)

• Internal updates for compliance with R's upcoming formalized C API. (#1625)

• Fixed an issue where attempting to convert a NumPy array with a non-simple
  dtype to R would signal an error. (#1613, fixed in #1614).

reticulate 1.37.0

• Interrupting Python no longer leads to segfaults.
  (#1601, fixed in #1602)

• Print method for Python callables now includes the callable’s signature.
  (#1605, #1607)

• Reticulate now installs successfully on Windows ARM64.
  (#1609, contributed by @andrjohns)

• virtualenv_starter() no longer warns when encountering broken symlinks.
  (#1598)

• Fixed issue where configuration for reticulate conda_* functions
  to use the executable mamba instead of conda was ignored.
  (#1608, contributed by @AlexandreGuinaudeau)

reticulate 1.36.1

• Fix issue where py_to_r() method for Pandas DataFrames would error
  if py_to_r() S3 methods were defined for Pandas subtypes,
  (as done by {anndata}) (#1591).

• "Python Dependencies" vignette edits (@salim-b, #1586)

• Added an option for extra command-line arguments in
  conda_create() and conda_install() (#1585).

• Fixed issue where conda_install() would ignore user-specified
  channels during Python installation (#1594).

reticulate 1.36.0

• Internal refactoring and optimization now give a faster experience,
  especially for workflows that frequently access Python objects from R.
  For example, simple attribute access like sys$path is ~2.5x times faster, and
  a sample workload of py_to_r(np_array(1:3) + np_array(1:3)) benchmarks
  ~3.5x faster when compared to the previous CRAN release.

• Fixed issue where callable python objects created with convert = FALSE would not be
  wrapped in an R function (#1522).

• Fixed issue where py_to_r() S3 methods would not be called on arguments supplied to
  R functions being called from Python (#1522).

• install_python() will now build optimized versions of Python on macOS and Linux (#1567)

• Default Python version installed by install_python() is now 3.10 (was 3.9) (#1574).

• Output of reticulate::py_last_error() now includes a hint, showing how to access
  the full R call stack (#1572).

• Fixed an issue where nested py_capture_output() calls result in a lost reference
  to the original sys.stdout and sys.stderr, resulting in no further visible output
  from Python, and eventually, a segfault. (#1564)

• Fixed issues reported by rchk, as requested by CRAN (#1581).

• py_to_r(x) now returns x unmodified if x is not a Python object,
  instead of signaling an error.

• New as.data.frame() method exported for Python Polars DataFrames (#1568)

• Fixed an issue where printing a delayed module (import("foo", delay_load = TRUE))
  would output <pointer: 0x0>.

• py_validate_xptr() will now attempt to resolve delayed modules before
  signaling an error (#1561).

• R packages can now express multiple preferred Python environments to
  search for and use if they exist, by supplying a character vector to import():
  import("foo", delay_load = list(environment = c("r-foo", "r-bar"))) (#1559)

• Reticulate will no longer warn about ignored use_python(,required = FALSE) calls (#1562).

• reticulate now prefers using the agg matplotlib backend when the R session
  is non-interactive. The backend can also be overridden via the MPLBACKEND or
  RETICULATE_MPLBACKEND environment variables when necessary (#1556).

• attr(x, "tzone") attributes are (better) preserved when converting POSIXt to Python.
  POSIXt types with a non-empty tzone attr convert to a datetime.datetime,
  otherwise they convert to NumPy datetime64[ns] arrays.

• Fixed an issue where calling py_set_item() on a subclassed dict would
  not invoke a custom __setitem__ method.

• py_del_attr(x, name) now returns x invisibly

• source_python() no longer exports the r symbol to the R global environment.
  (the "R Interface Object" that is used by Python code get a reference to the
  R globalenv())

• Fixed hang encountered (sometimes) when attempting to call iterate()
  on an exhausted py_iterator() object multiple times (#1539).

• iterate(simplify=TRUE) rewritten in C for speed improvements (#1539).

• Update for Pandas 2.2 deprecation of Index.format() (#1537, #1538).

• Updates for CRAN R-devel (R 4.4) (#1554).

• Fixed an issue where py_discover_config() would discover python (v2) on the PATH
  in preference of python3 on the PATH. (#1547)

• Fixed an issue where reticulate would error when using conda environments created
  with the (new) conda env create command. (#1535, #1543)

• Fixed an issue where reticulate would error when using a conda environment
  where the original conda binary that was used to create the environment
  is no longer available (#1555)

• Fixed an issue where a user would be unable to accept the prompt to create
  the default "r-reticulate" venv (#1557).

• is_py_object() is now exported (#1573).

reticulate 1.35.0

• Subclassed Python list and dict objects are no longer automatically converted
  to R vectors. Additionally, the S3 R class attribute for Python objects is
  now constructed using the Python type(object) directly, rather than from the
  object.__class__ attribute. See #1531 for details and context.

• R external pointers (EXTPTRSXP objects) now round-trip through
  py_to_r(r_to_py(x)) successfully.
  (reported in #1511, fixed in #1519, contributed by @llaniewski).

• Fixed issue where virtualenv_create() would error on Ubuntu 22.04 when
  using the system python as a base. (#1495, fixed in #1496).

• Fixed issue where csc_matrix objects with unsorted indices could not be
  converted to a dgCMatrix. (related to #727, fixed in #1524, contributed by @rcannood).

• Added support for partially unexpanded variables like $USER in
  XDG_DATA_HOME and similar (#1513, #1514)

Knitr Python Engine Changes:

• The knitr python engine now formats captured python exceptions to include the
  exception type and any exception notes when chunk options
  error = TRUE is set (reported in #1520, fixed in #1527).

• Fixed an issue where the knitr python engine would fail to include
  figures from python chunks if a custom root.dir chunk option was set.
  (reported in #1526, fixed in #1529)

• knitr engine gains the ability to save chunk figures in multiple files/formats
  (Contributed by @Rumengol in #1507)

• Fixed an issue where matplotlib figures generated in the initial chunk
  where matplotlib was first imported would be the wrong size
  (reported in #1523, fixed in #1530)

• Fixed an issue where the knitr engine would not correctly display altair
  compound charts if more than one were present in a document (#1500, #1532).

reticulate 1.34.0

v1.34.0

Increment version number to 1.34.0

reticulate 1.32.0

• reticulate now supports casting R data.frames to Pandas data.frames using nullable
  data types, allowing users to preserve NA's from R atomic vectors. This feature is
  opt-in and can be enabled by setting the R option reticulate.pandas_use_nullable_dtypes
  to TRUE. (#1439)

• reticulate now exports a chooseOpsMethod() method, allowing for Ops dispatch
  to more specialized Ops methods defined for Python objects.

• py_discover_config() will now warn instead of error upon encountering a
  broken Python installation. (#1441, #1459)

• Fixed issue where Python would raise exception "OSError: [WinError 6] The handle is invalid"
  when opening a subprocess while running in Rstudio on Windows. (#1448, #518)

• Fixed issue where the multiprocessing Python module would crash or hang when spawning a
  Process() on Windows. (#1430, #1346, fixed in #1461)

• Fixed issue where virtualenv_create() would fail to discover a 'virtualenv' module
  in the system Python installation on Ubuntu. Reticulate will no longer discover
  and attempt to use the venv module stub present on Ubuntu systems
  where the python3-venv apt package has not been installed.
  (mlverse/pysparklyr#11, #1437, #1455)

• Fixed issue where the user was prompted to create an 'r-reticulate' venv
  in the RStudio IDE before reticulate was requested to initialize Python. (#1450, #1456)

• Improved error message when reticulate attempts to initialize a virtual environment
  after the Python installation it was created from is no longer available. (#1149, #1457)

• Improved error message on Fedora when attempting to create a virtual environment
  from the system python before running dnf install python3-pip.

• Fixed issue where install_python() on macOS in the RStudio IDE would fail to discover
  and use brew for Python build dependencies.

• Fixed error with virtualenv_create(python = "/usr/bin/python") on centos7. (#1467)