From 7035daf5f1f9516b578a6cd9588a181a7ea349ba Mon Sep 17 00:00:00 2001
From: Merrin Macleod <merrin.macleod@gmail.com>
Date: Sun, 30 Jun 2024 23:34:43 +1200
Subject: [PATCH 01/18] =?UTF-8?q?=F0=9F=8E=A8=20Fix=20styling=20of=20docs?=
 =?UTF-8?q?=20headings=20in=20dark=20mode=20(#2026)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/_static/style.css | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/docs/_static/style.css b/docs/_static/style.css
index b2bc297d6..a2ac3f7fd 100644
--- a/docs/_static/style.css
+++ b/docs/_static/style.css
@@ -38,8 +38,14 @@ pre, code {
 
 .sd-card .sd-card-header {
   border: none;
-  color: #150458 !important;
+  color: #150458;
   font-size: var(--pst-font-size-h5);
   font-weight: bold;
   padding: 2.5rem 0rem 0.5rem 0rem;
 }
+
+html[data-theme=dark] {
+  .sd-card .sd-card-header {
+    color: #FFF;
+  }
+}

From 74e2e6a095f3df0bcb3ce95365efe2f1f7786acc Mon Sep 17 00:00:00 2001
From: Haris Musaefenidc <haris.musaefendic@gmail.com>
Date: Mon, 8 Jul 2024 14:05:22 +0200
Subject: [PATCH 02/18] =?UTF-8?q?Add=20permille=20units=20with=20=E2=80=B0?=
 =?UTF-8?q?=20symbol=20(#2033)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 CHANGES                       |  2 +-
 pint/default_en.txt           |  1 +
 pint/facets/plain/registry.py |  3 +++
 pint/testsuite/test_issues.py | 18 ++++++++++++++++++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index 53e5a5fc5..e2999fddb 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,7 +4,7 @@ Pint Changelog
 0.25 (unreleased)
 -----------------
 
-- Nothing added yet.
+- Support permille units and `‰` symbol (PR #2033, Issue #1963)
 
 
 0.24.1 (2024-06-24)
diff --git a/pint/default_en.txt b/pint/default_en.txt
index 45f241f18..68160a983 100644
--- a/pint/default_en.txt
+++ b/pint/default_en.txt
@@ -150,6 +150,7 @@ byte = 8 * bit = B = octet
 
 # Ratios
 percent = 0.01 = %
+permille = 0.001 = ‰
 ppm = 1e-6
 
 # Length
diff --git a/pint/facets/plain/registry.py b/pint/facets/plain/registry.py
index 09fd220ee..c5c0be783 100644
--- a/pint/facets/plain/registry.py
+++ b/pint/facets/plain/registry.py
@@ -255,6 +255,9 @@ def __init__(
         # use a default preprocessor to support "%"
         self.preprocessors.insert(0, lambda string: string.replace("%", " percent "))
 
+        # use a default preprocessor to support permille "‰"
+        self.preprocessors.insert(0, lambda string: string.replace("‰", " permille "))
+
         #: mode used to fill in the format defaults
         self.separate_format_defaults = separate_format_defaults
 
diff --git a/pint/testsuite/test_issues.py b/pint/testsuite/test_issues.py
index 97eca3cde..c4e42eacc 100644
--- a/pint/testsuite/test_issues.py
+++ b/pint/testsuite/test_issues.py
@@ -884,6 +884,24 @@ def test_issue1277(self, module_registry):
         assert c.to("percent").m == 50
         # assert c.to("%").m == 50  # TODO: fails.
 
+    def test_issue1963(self, module_registry):
+        ureg = module_registry
+        assert ureg("‰") == ureg("permille")
+        assert ureg("‰") == ureg.permille
+
+        a = ureg.Quantity("10 ‰")
+        b = ureg.Quantity("100 ppm")
+        c = ureg.Quantity("0.5")
+
+        assert f"{a}" == "10 permille"
+        assert f"{a:~}" == "10 ‰"
+
+        assert_equal(a, 0.01)
+        assert_equal(1e2 * b, a)
+        assert_equal(c, 50 * a)
+
+        assert_equal((1 * ureg.milligram) / (1 * ureg.gram), ureg.permille)
+
     @pytest.mark.xfail
     @helpers.requires_uncertainties()
     def test_issue_1300(self):

From 6483353b66bbd1e923b0682ed2c9496b7c3f8205 Mon Sep 17 00:00:00 2001
From: Tom Gillespie <tgbugs@gmail.com>
Date: Mon, 8 Jul 2024 08:10:59 -0400
Subject: [PATCH 03/18] ensure uncertainties does not depend on numpy (#2001)

---
 pint/compat.py                | 5 ++++-
 pint/testsuite/test_issues.py | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/pint/compat.py b/pint/compat.py
index 32ad04afb..b968803ce 100644
--- a/pint/compat.py
+++ b/pint/compat.py
@@ -75,7 +75,8 @@ class BehaviorChangeWarning(UserWarning):
 
 try:
     from uncertainties import UFloat, ufloat
-    from uncertainties import unumpy as unp
+
+    unp = None
 
     HAS_UNCERTAINTIES = True
 except ImportError:
@@ -92,6 +93,8 @@ class BehaviorChangeWarning(UserWarning):
     HAS_NUMPY = True
     NUMPY_VER = np.__version__
     if HAS_UNCERTAINTIES:
+        from uncertainties import unumpy as unp
+
         NUMERIC_TYPES = (Number, Decimal, ndarray, np.number, UFloat)
     else:
         NUMERIC_TYPES = (Number, Decimal, ndarray, np.number)
diff --git a/pint/testsuite/test_issues.py b/pint/testsuite/test_issues.py
index c4e42eacc..f726a950c 100644
--- a/pint/testsuite/test_issues.py
+++ b/pint/testsuite/test_issues.py
@@ -940,6 +940,7 @@ def test_issue_1400(self, sess_registry):
         assert q2.format_babel("~", locale="es_ES") == "3,1 W/cm"
         assert q2.format_babel("", locale="es_ES") == "3,1 vatios por centímetro"
 
+    @helpers.requires_numpy()
     @helpers.requires_uncertainties()
     def test_issue1611(self, module_registry):
         from numpy.testing import assert_almost_equal

From bffbbc21d93ce19bac1af94d4ac8939851e15e9a Mon Sep 17 00:00:00 2001
From: SPKorhonen <samuli-petrus.korhonen@iki.fi>
Date: Mon, 8 Jul 2024 17:13:45 +0300
Subject: [PATCH 04/18] =?UTF-8?q?Add=20=E2=84=93=20as=20alternative=20for?=
 =?UTF-8?q?=20liter=20(#2014)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 CHANGES                       | 1 +
 pint/default_en.txt           | 2 +-
 pint/testsuite/test_issues.py | 3 +++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index e2999fddb..37ca16b87 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,7 @@ Pint Changelog
 0.25 (unreleased)
 -----------------
 
+- Added ℓ as alternative for liter
 - Support permille units and `‰` symbol (PR #2033, Issue #1963)
 
 
diff --git a/pint/default_en.txt b/pint/default_en.txt
index 68160a983..c87c5f0d5 100644
--- a/pint/default_en.txt
+++ b/pint/default_en.txt
@@ -222,7 +222,7 @@ hectare = 100 * are = ha
 
 # Volume
 [volume] = [length] ** 3
-liter = decimeter ** 3 = l = L = litre
+liter = decimeter ** 3 = l = L = ℓ = litre
 cubic_centimeter = centimeter ** 3 = cc
 lambda = microliter = λ
 stere = meter ** 3
diff --git a/pint/testsuite/test_issues.py b/pint/testsuite/test_issues.py
index f726a950c..760b886f7 100644
--- a/pint/testsuite/test_issues.py
+++ b/pint/testsuite/test_issues.py
@@ -408,6 +408,9 @@ def test_micro_creation_U03bc(self, module_registry):
     def test_micro_creation_U00b5(self, module_registry):
         module_registry.Quantity(2, "µm")
 
+    def test_liter_creation_U2113(self, module_registry):
+        module_registry.Quantity(2, "ℓ")
+
     @helpers.requires_numpy
     def test_issue171_real_imag(self, module_registry):
         qr = [1.0, 2.0, 3.0, 4.0] * module_registry.meter

From f9c381c1e89ffb7ce9e6268516f9291ca5351d6f Mon Sep 17 00:00:00 2001
From: SPKorhonen <samuli-petrus.korhonen@iki.fi>
Date: Mon, 8 Jul 2024 17:24:38 +0300
Subject: [PATCH 05/18] Added "mu" and "mc" prefixes. (#2013)

---
 CHANGES                       | 1 +
 pint/default_en.txt           | 2 +-
 pint/testsuite/conftest.py    | 2 +-
 pint/testsuite/test_issues.py | 6 ++++++
 4 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index 37ca16b87..208dbad06 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,7 @@ Pint Changelog
 0.25 (unreleased)
 -----------------
 
+- Added mu and mc as alternatives for SI micro prefix
 - Added ℓ as alternative for liter
 - Support permille units and `‰` symbol (PR #2033, Issue #1963)
 
diff --git a/pint/default_en.txt b/pint/default_en.txt
index c87c5f0d5..4250a48cb 100644
--- a/pint/default_en.txt
+++ b/pint/default_en.txt
@@ -72,7 +72,7 @@ pico- =  1e-12 = p-
 nano- =  1e-9  = n-
 # The micro (U+00B5) and Greek mu (U+03BC) are both valid prefixes,
 # and they often use the same glyph.
-micro- = 1e-6  = µ- = μ- = u-
+micro- = 1e-6  = µ- = μ- = u- = mu- = mc-
 milli- = 1e-3  = m-
 centi- = 1e-2  = c-
 deci- =  1e-1  = d-
diff --git a/pint/testsuite/conftest.py b/pint/testsuite/conftest.py
index 775480f0b..0a42f44af 100644
--- a/pint/testsuite/conftest.py
+++ b/pint/testsuite/conftest.py
@@ -14,7 +14,7 @@
 femto- = 1e-15 = f-
 pico- =  1e-12 = p-
 nano- =  1e-9  = n-
-micro- = 1e-6  = µ- = μ- = u-
+micro- = 1e-6  = µ- = μ- = u- = mu- = mc-
 milli- = 1e-3  = m-
 centi- = 1e-2  = c-
 deci- =  1e-1  = d-
diff --git a/pint/testsuite/test_issues.py b/pint/testsuite/test_issues.py
index 760b886f7..847f269f0 100644
--- a/pint/testsuite/test_issues.py
+++ b/pint/testsuite/test_issues.py
@@ -408,6 +408,12 @@ def test_micro_creation_U03bc(self, module_registry):
     def test_micro_creation_U00b5(self, module_registry):
         module_registry.Quantity(2, "µm")
 
+    def test_micro_creation_mu(self, module_registry):
+        module_registry.Quantity(2, "mug")
+
+    def test_micro_creation_mc(self, module_registry):
+        module_registry.Quantity(2, "mcg")
+
     def test_liter_creation_U2113(self, module_registry):
         module_registry.Quantity(2, "ℓ")
 

From b2fc74a7d6038d206d158804daa32e1698f89c26 Mon Sep 17 00:00:00 2001
From: Pratyush Das <dpratyush.k@gmail.com>
Date: Mon, 8 Jul 2024 21:40:58 +0700
Subject: [PATCH 06/18] Fix cli uncertainty package import (#2032)

---
 CHANGES                   |  2 ++
 docs/dev/pint-convert.rst | 27 +++++++++++++++------------
 pint/pint_convert.py      | 28 ++++++++++++++++++++--------
 3 files changed, 37 insertions(+), 20 deletions(-)
 mode change 100755 => 100644 pint/pint_convert.py

diff --git a/CHANGES b/CHANGES
index 208dbad06..5ee199f2c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,8 +4,10 @@ Pint Changelog
 0.25 (unreleased)
 -----------------
 
+- Fix the default behaviour for pint-convert (cli) for importing uncertainties package
 - Added mu and mc as alternatives for SI micro prefix
 - Added ℓ as alternative for liter
+- Fix the default behaviour for pint-convert (cli) for importing uncertainties package (PR #2032, Issue #2016)
 - Support permille units and `‰` symbol (PR #2033, Issue #1963)
 
 
diff --git a/docs/dev/pint-convert.rst b/docs/dev/pint-convert.rst
index dbb0804f4..4ba0ad888 100644
--- a/docs/dev/pint-convert.rst
+++ b/docs/dev/pint-convert.rst
@@ -77,36 +77,39 @@ With the `uncertainties` package, the experimental uncertainty in the physical
 constants is considered, and the result is given in compact notation, with the
 uncertainty in the last figures in parentheses:
 
+The uncertainty can be enabled with `-U` (by default it is not enabled):
+
+.. code-block:: console
+
+    $ pint-convert -p 20 -U Eh eV
+    1 hartree = 27.211386245988(52) eV
+
 .. code-block:: console
 
-    $ pint-convert Eh eV
+    $ pint-convert -U Eh eV
     1 hartree = 27.21138624599(5) eV
 
 The precision is limited by both the maximum number of significant digits (`-p`)
 and the maximum number of uncertainty digits (`-u`, 2 by default)::
 
-    $ pint-convert -p 20 Eh eV
+    $ pint-convert -U -p 20 Eh eV
     1 hartree = 27.211386245988(52) eV
 
-    $ pint-convert -p 20 -u 4 Eh eV
+    $ pint-convert -U -p 20 -u 4 Eh eV
     1 hartree = 27.21138624598847(5207) eV
 
-The uncertainty can be disabled with `-U`):
-
-.. code-block:: console
-
-    $ pint-convert -p 20 -U Eh eV
-    1 hartree = 27.211386245988471444 eV
-
 Correlations between experimental constants are also known, and taken into
-account. Use `-C` to disable it:
+account if uncertainties `-U` is enabled. Use `-C` to disable it:
 
 .. code-block:: console
 
     $ pint-convert --sys atomic m_p
+    1 proton_mass = 1836.15267344 m_e
+
+    $ pint-convert -U --sys atomic m_p
     1 proton_mass = 1836.15267344(11) m_e
 
-    $ pint-convert --sys atomic -C m_p
+    $ pint-convert -U --sys atomic -C m_p
     1 proton_mass = 1836.15267344(79) m_e
 
 Again, note that results may differ slightly, usually in the last figure, from
diff --git a/pint/pint_convert.py b/pint/pint_convert.py
old mode 100755
new mode 100644
index bf9097237..0934588b8
--- a/pint/pint_convert.py
+++ b/pint/pint_convert.py
@@ -42,10 +42,10 @@
 )
 parser.add_argument(
     "-U",
-    "--no-unc",
+    "--with-unc",
     dest="unc",
-    action="store_false",
-    help="ignore uncertainties in constants",
+    action="store_true",
+    help="consider uncertainties in constants",
 )
 parser.add_argument(
     "-C",
@@ -77,7 +77,12 @@ def _set(key: str, value):
 
 
 if args.unc:
-    import uncertainties
+    try:
+        import uncertainties
+    except ImportError:
+        raise Exception(
+            "Failed to import uncertainties library!\n Please install uncertainties package"
+        )
 
     # Measured constants subject to correlation
     #  R_i: Rydberg constant
@@ -103,9 +108,14 @@ def _set(key: str, value):
             [0.00194, 0.97560, 0.98516, 0.98058, 1.0, 0.51521],  # m_p
             [0.00233, 0.52445, 0.52959, 0.52714, 0.51521, 1.0],
         ]  # m_n
-        (R_i, g_e, m_u, m_e, m_p, m_n) = uncertainties.correlated_values_norm(
-            [R_i, g_e, m_u, m_e, m_p, m_n], corr
-        )
+        try:
+            (R_i, g_e, m_u, m_e, m_p, m_n) = uncertainties.correlated_values_norm(
+                [R_i, g_e, m_u, m_e, m_p, m_n], corr
+            )
+        except AttributeError:
+            raise Exception(
+                "Correlation cannot be calculated!\n  Please install numpy package"
+            )
     else:
         R_i = uncertainties.ufloat(*R_i)
         g_e = uncertainties.ufloat(*g_e)
@@ -160,6 +170,7 @@ def _set(key: str, value):
 
 
 def convert(u_from, u_to=None, unc=None, factor=None):
+    prec_unc = 0
     q = ureg.Quantity(u_from)
     fmt = f".{args.prec}g"
     if unc:
@@ -171,7 +182,8 @@ def convert(u_from, u_to=None, unc=None, factor=None):
     if factor:
         q *= ureg.Quantity(factor)
         nq *= ureg.Quantity(factor).to_base_units()
-    prec_unc = use_unc(nq.magnitude, fmt, args.prec_unc)
+    if args.unc:
+        prec_unc = use_unc(nq.magnitude, fmt, args.prec_unc)
     if prec_unc > 0:
         fmt = f".{prec_unc}uS"
     else:

From 1e46b2ee8f439703606757472769c10fb7586d83 Mon Sep 17 00:00:00 2001
From: mutricyl <118692416+mutricyl@users.noreply.github.com>
Date: Fri, 12 Jul 2024 15:49:42 +0200
Subject: [PATCH 07/18] 2035 pandas3 (#2036)

---
 pint/compat.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pint/compat.py b/pint/compat.py
index b968803ce..4b4cbab92 100644
--- a/pint/compat.py
+++ b/pint/compat.py
@@ -240,6 +240,8 @@ def _to_magnitude(value, force_ndarray=False, force_ndarray_like=False):
     "xarray.core.variable.Variable",
     "pandas.core.series.Series",
     "pandas.core.frame.DataFrame",
+    "pandas.Series",
+    "pandas.DataFrame",
     "xarray.core.dataarray.DataArray",
 )
 

From 5f2a76a42c44f0077908be212c5445a657da639a Mon Sep 17 00:00:00 2001
From: Pratyush Das <dpratyush.k@gmail.com>
Date: Sat, 13 Jul 2024 17:24:56 +0700
Subject: [PATCH 08/18] [DOC] Update changelog (#2034)

---
 CHANGES | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index 5ee199f2c..bfe99d479 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,10 +4,9 @@ Pint Changelog
 0.25 (unreleased)
 -----------------
 
-- Fix the default behaviour for pint-convert (cli) for importing uncertainties package
+- Fix the default behaviour for pint-convert (cli) for importing uncertainties package (PR #2032, Issue #2016)
 - Added mu and mc as alternatives for SI micro prefix
 - Added ℓ as alternative for liter
-- Fix the default behaviour for pint-convert (cli) for importing uncertainties package (PR #2032, Issue #2016)
 - Support permille units and `‰` symbol (PR #2033, Issue #1963)
 
 

From 0faac0760cf36a72d23463d5012644d751b4c8d7 Mon Sep 17 00:00:00 2001
From: andrewgsavage <andrewgsavage@gmail.com>
Date: Sun, 28 Jul 2024 01:12:52 +0100
Subject: [PATCH 09/18] add error for prefixed non multi units (#1998)

---
 CHANGES                       |  2 ++
 pint/facets/plain/registry.py | 12 +++++++++++-
 pint/testsuite/test_unit.py   |  5 +++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index bfe99d479..15d479972 100644
--- a/CHANGES
+++ b/CHANGES
@@ -45,6 +45,8 @@ Pint Changelog
   (PR #1949)
 - Fix unhandled TypeError when auto_reduce_dimensions=True and non_int_type=Decimal
   (PR #1853)
+- Creating prefixed offset units now raises an error.
+  (PR #1998)
 - Improved error message in `get_dimensionality()` when non existent units are passed.
   (PR #1874, Issue #1716)
 
diff --git a/pint/facets/plain/registry.py b/pint/facets/plain/registry.py
index c5c0be783..325f2c315 100644
--- a/pint/facets/plain/registry.py
+++ b/pint/facets/plain/registry.py
@@ -60,7 +60,12 @@
     UnitLike,
 )
 from ...compat import Self, TypeAlias, deprecated
-from ...errors import DimensionalityError, RedefinitionError, UndefinedUnitError
+from ...errors import (
+    DimensionalityError,
+    OffsetUnitCalculusError,
+    RedefinitionError,
+    UndefinedUnitError,
+)
 from ...pint_eval import build_eval_tree
 from ...util import (
     ParserHelper,
@@ -667,6 +672,11 @@ def get_name(self, name_or_alias: str, case_sensitive: bool | None = None) -> st
             )
 
         if prefix:
+            if not self._units[unit_name].is_multiplicative:
+                raise OffsetUnitCalculusError(
+                    "Prefixing a unit requires multiplying the unit."
+                )
+
             name = prefix + unit_name
             symbol = self.get_symbol(name, case_sensitive)
             prefix_def = self._prefixes[prefix]
diff --git a/pint/testsuite/test_unit.py b/pint/testsuite/test_unit.py
index 2156bbafd..1cca93cec 100644
--- a/pint/testsuite/test_unit.py
+++ b/pint/testsuite/test_unit.py
@@ -1043,3 +1043,8 @@ def test_alias(self):
         # Define against unknown name
         with pytest.raises(KeyError):
             ureg.define("@alias notexist = something")
+
+    def test_prefix_offset_units(self):
+        ureg = UnitRegistry()
+        with pytest.raises(errors.OffsetUnitCalculusError):
+            ureg.parse_units("kilodegree_Celsius")

From 67303b8e20f1d4023bc5e0e7cb68f0c08855ba2c Mon Sep 17 00:00:00 2001
From: andrewgsavage <andrewgsavage@gmail.com>
Date: Sun, 28 Jul 2024 01:14:45 +0100
Subject: [PATCH 10/18] build: typing_extensions version

closes #1996
---
 CHANGES          | 2 ++
 requirements.txt | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index 15d479972..6c3c827ae 100644
--- a/CHANGES
+++ b/CHANGES
@@ -32,6 +32,8 @@ Pint Changelog
 - Add `dim_sort` function to _formatter_helpers.
 - Add `dim_order` and `default_sort_func` properties to FullFormatter.
   (PR #1926, fixes Issue #1841)
+- Minimum version requirement added for typing_extensions>=4.0.0.
+  (PR #1996)
 - Documented packages using pint.
   (PR #1960)
 - Fixed bug causing operations between arrays of quantity scalars and quantity holding
diff --git a/requirements.txt b/requirements.txt
index 0bc99005a..dc7cf4651 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 appdirs>=1.4.4
-typing_extensions
+typing_extensions>=4.0.0
 flexcache>=0.3
 flexparser>=0.3

From 0b0ae61cebe6c470dcc2edbb84fe717c664fc223 Mon Sep 17 00:00:00 2001
From: Steve Kowalik <steven@wedontsleep.org>
Date: Mon, 29 Jul 2024 02:13:26 +1000
Subject: [PATCH 11/18] build: switch from appdirs to platformdirs

appdirs has been officially deprecated upstream, the replacement module
with more features is platformdirs.

Closes #2028
---
 CHANGES                       | 1 +
 docs/advanced/performance.rst | 4 ++--
 pint/facets/plain/registry.py | 5 ++---
 requirements.txt              | 2 +-
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/CHANGES b/CHANGES
index 6c3c827ae..4b4884d54 100644
--- a/CHANGES
+++ b/CHANGES
@@ -8,6 +8,7 @@ Pint Changelog
 - Added mu and mc as alternatives for SI micro prefix
 - Added ℓ as alternative for liter
 - Support permille units and `‰` symbol (PR #2033, Issue #1963)
+- Switch from appdirs to platformdirs.
 
 
 0.24.1 (2024-06-24)
diff --git a/docs/advanced/performance.rst b/docs/advanced/performance.rst
index d7b8a0cd5..998cac681 100644
--- a/docs/advanced/performance.rst
+++ b/docs/advanced/performance.rst
@@ -120,7 +120,7 @@ If you want to use the default cache folder provided by the OS, use **:auto:**
     >>> import pint
     >>> ureg = pint.UnitRegistry(cache_folder=":auto:")  # doctest: +SKIP
 
-Pint use an included version of appdirs_ to obtain the correct folder,
+Pint use an external dependency of platformdirs_ to obtain the correct folder,
 for example in macOS is `/Users/<username>/Library/Caches/pint`
 
 In any case, you can check the location of the cache folder.
@@ -146,5 +146,5 @@ In any case, you can check the location of the cache folder.
 
 
 .. _`brentq method`: http://docs.scipy.org/doc/scipy/reference/generated/scipy.optimize.brentq.html
-.. _appdirs: https://pypi.org/project/appdirs/
+.. _platformdirs: https://pypi.org/project/platformdirs
 .. _flexcache: https://github.com/hgrecco/flexcache/
diff --git a/pint/facets/plain/registry.py b/pint/facets/plain/registry.py
index 325f2c315..c8ce3f2f0 100644
--- a/pint/facets/plain/registry.py
+++ b/pint/facets/plain/registry.py
@@ -49,7 +49,7 @@
 
     # from ..._typing import Quantity, Unit
 
-import appdirs
+import platformdirs
 
 from ... import pint_eval
 from ..._typing import (
@@ -238,8 +238,7 @@ def __init__(
         self._init_dynamic_classes()
 
         if cache_folder == ":auto:":
-            cache_folder = appdirs.user_cache_dir(appname="pint", appauthor=False)
-            cache_folder = pathlib.Path(cache_folder)
+            cache_folder = platformdirs.user_cache_path(appname="pint", appauthor=False)
 
         from ... import delegates  # TODO: change thiss
 
diff --git a/requirements.txt b/requirements.txt
index dc7cf4651..c62365819 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-appdirs>=1.4.4
+platformdirs>=2.1.0
 typing_extensions>=4.0.0
 flexcache>=0.3
 flexparser>=0.3

From 8f12bb923adb69cf2a772c4f2cb10ee3ef9dd11a Mon Sep 17 00:00:00 2001
From: Bogdan Reznychenko <100156521+theodotk@users.noreply.github.com>
Date: Mon, 19 Aug 2024 13:51:19 -0700
Subject: [PATCH 12/18] fix GenericPlainRegistry getattr type (#2045)

---
 CHANGES                         | 1 +
 pint/facets/plain/registry.py   | 2 +-
 pint/testsuite/test_quantity.py | 8 ++++++++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index 4b4884d54..9d7de4298 100644
--- a/CHANGES
+++ b/CHANGES
@@ -9,6 +9,7 @@ Pint Changelog
 - Added ℓ as alternative for liter
 - Support permille units and `‰` symbol (PR #2033, Issue #1963)
 - Switch from appdirs to platformdirs.
+- Fixes issues related to GenericPlainRegistry.__getattr__ type (PR #2038, Issues #1946 and #1804)
 
 
 0.24.1 (2024-06-24)
diff --git a/pint/facets/plain/registry.py b/pint/facets/plain/registry.py
index c8ce3f2f0..be70a2ca8 100644
--- a/pint/facets/plain/registry.py
+++ b/pint/facets/plain/registry.py
@@ -367,7 +367,7 @@ def __deepcopy__(self: Self, memo) -> type[Self]:
         new._init_dynamic_classes()
         return new
 
-    def __getattr__(self, item: str) -> QuantityT:
+    def __getattr__(self, item: str) -> UnitT:
         getattr_maybe_raise(self, item)
 
         # self.Unit will call parse_units
diff --git a/pint/testsuite/test_quantity.py b/pint/testsuite/test_quantity.py
index 8c6f15c49..26a5ee05d 100644
--- a/pint/testsuite/test_quantity.py
+++ b/pint/testsuite/test_quantity.py
@@ -2014,3 +2014,11 @@ def test_offset_autoconvert_gt_zero(self):
         assert q2 > 0
         with pytest.raises(DimensionalityError):
             q1.__gt__(ureg.Quantity(0, ""))
+
+    def test_types(self):
+        quantity = self.Q_(1.0, "m")
+        assert isinstance(quantity, self.Q_)
+        assert isinstance(quantity.units, self.ureg.Unit)
+        assert isinstance(quantity.m, float)
+
+        assert isinstance(self.ureg.m, self.ureg.Unit)

From 2839f6e23f48dd393c375c44581574afec04ff43 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mar=C3=A7al=20Gabald=C3=A0?= <mgab@users.noreply.github.com>
Date: Fri, 4 Oct 2024 21:05:33 +0200
Subject: [PATCH 13/18] Replace references to the deprecated
 `UnitRegistry.default_format` (#2058)

---
 CHANGES                      |  1 +
 docs/getting/tutorial.rst    |  4 ++--
 docs/user/nonmult.rst        |  2 +-
 pint/testsuite/test_babel.py |  2 +-
 pint/testsuite/test_unit.py  | 16 ++++++++--------
 5 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/CHANGES b/CHANGES
index 9d7de4298..de1c3bccb 100644
--- a/CHANGES
+++ b/CHANGES
@@ -10,6 +10,7 @@ Pint Changelog
 - Support permille units and `‰` symbol (PR #2033, Issue #1963)
 - Switch from appdirs to platformdirs.
 - Fixes issues related to GenericPlainRegistry.__getattr__ type (PR #2038, Issues #1946 and #1804)
+- Removed deprecated references in documentation and tests (PR #2058, Issue #2057)
 
 
 0.24.1 (2024-06-24)
diff --git a/docs/getting/tutorial.rst b/docs/getting/tutorial.rst
index d675860f2..a0836fe7e 100644
--- a/docs/getting/tutorial.rst
+++ b/docs/getting/tutorial.rst
@@ -415,7 +415,7 @@ Additionally, you can specify a default format specification:
    >>> accel = 1.3 * ureg.parse_units('meter/second**2')
    >>> 'The acceleration is {}'.format(accel)
    'The acceleration is 1.3 meter / second ** 2'
-   >>> ureg.default_format = 'P'
+   >>> ureg.formatter.default_format = 'P'
    >>> 'The acceleration is {}'.format(accel)
    'The acceleration is 1.3 meter/second²'
 
@@ -446,7 +446,7 @@ and by doing that, string formatting is now localized:
 
 .. doctest::
 
-    >>> ureg.default_format = 'P'
+    >>> ureg.formatter.default_format = 'P'
     >>> accel = 1.3 * ureg.parse_units('meter/second**2')
     >>> str(accel)
     '1,3 mètres par seconde²'
diff --git a/docs/user/nonmult.rst b/docs/user/nonmult.rst
index a649d2ad1..905dd0835 100644
--- a/docs/user/nonmult.rst
+++ b/docs/user/nonmult.rst
@@ -18,7 +18,7 @@ For example, to convert from celsius to fahrenheit:
 
     >>> from pint import UnitRegistry
     >>> ureg = UnitRegistry()
-    >>> ureg.default_format = '.3f'
+    >>> ureg.formatter.default_format = '.3f'
     >>> Q_ = ureg.Quantity
     >>> home = Q_(25.4, ureg.degC)
     >>> print(home.to('degF'))
diff --git a/pint/testsuite/test_babel.py b/pint/testsuite/test_babel.py
index 9adcb04a9..c68c641e7 100644
--- a/pint/testsuite/test_babel.py
+++ b/pint/testsuite/test_babel.py
@@ -66,7 +66,7 @@ def test_unit_format_babel():
     volume = ureg.Unit("ml")
     assert volume.format_babel() == "millilitre"
 
-    ureg.default_format = "~"
+    ureg.formatter.default_format = "~"
     assert volume.format_babel() == "ml"
 
     dimensionless_unit = ureg.Unit("")
diff --git a/pint/testsuite/test_unit.py b/pint/testsuite/test_unit.py
index 1cca93cec..78d72e856 100644
--- a/pint/testsuite/test_unit.py
+++ b/pint/testsuite/test_unit.py
@@ -70,7 +70,7 @@ def test_latex_escaping(self, subtests):
             "Lx~": r"\si[]{\%}",
         }.items():
             with subtests.test(spec):
-                ureg.default_format = spec
+                ureg.formatter.default_format = spec
                 assert f"{x}" == result, f"Failed for {spec}, got {x} expected {result}"
         # no '#' here as it's a comment char when define()ing new units
         ureg.define(r"weirdunit = 1 = \~_^&%$_{}")
@@ -83,7 +83,7 @@ def test_latex_escaping(self, subtests):
             # "Lx~": r"\si[]{\textbackslash \textasciitilde \_\textasciicircum \&\%\$\_\{\}}",
         }.items():
             with subtests.test(spec):
-                ureg.default_format = spec
+                ureg.formatter.default_format = spec
                 assert f"{x}" == result, f"Failed for {spec}, {result}"
 
     def test_unit_default_formatting(self, subtests):
@@ -104,13 +104,13 @@ def test_unit_default_formatting(self, subtests):
             ("C~", "kg*m**2/s"),
         ):
             with subtests.test(spec):
-                ureg.default_format = spec
+                ureg.formatter.default_format = spec
                 assert f"{x}" == result, f"Failed for {spec}, {result}"
 
     @pytest.mark.xfail(reason="Still not clear how default formatting will work.")
     def test_unit_formatting_defaults_warning(self):
         ureg = UnitRegistry()
-        ureg.default_format = "~P"
+        ureg.formatter.default_format = "~P"
         x = ureg.Unit("m / s ** 2")
 
         with pytest.warns(DeprecationWarning):
@@ -136,7 +136,7 @@ def test_unit_formatting_snake_case(self, subtests):
             ("C~", "oil_bbl"),
         ):
             with subtests.test(spec):
-                ureg.default_format = spec
+                ureg.formatter.default_format = spec
                 assert f"{x}" == result, f"Failed for {spec}, {result}"
 
     def test_unit_formatting_custom(self, monkeypatch):
@@ -177,7 +177,7 @@ def pretty(cls, data):
         )
         x._repr_pretty_(Pretty, False)
         assert "".join(alltext) == "kilogram·meter²/second"
-        ureg.default_format = "~"
+        ureg.formatter.default_format = "~"
         assert x._repr_html_() == "kg m<sup>2</sup>/s"
         assert (
             x._repr_latex_() == r"$\frac{\mathrm{kg} \cdot \mathrm{m}^{2}}{\mathrm{s}}$"
@@ -322,11 +322,11 @@ def test_default_format(self):
         q = ureg.meter
         s1 = f"{q}"
         s2 = f"{q:~}"
-        ureg.default_format = "~"
+        ureg.formatter.default_format = "~"
         s3 = f"{q}"
         assert s2 == s3
         assert s1 != s3
-        assert ureg.default_format == "~"
+        assert ureg.formatter.default_format == "~"
 
     def test_iterate(self):
         ureg = UnitRegistry()

From d592aff209a0eeae9383042368906dfb5edc5f54 Mon Sep 17 00:00:00 2001
From: Hernan Grecco <hgrecco@gmail.com>
Date: Wed, 6 Nov 2024 23:34:42 -0300
Subject: [PATCH 14/18] fix: upgrade to flexparser>=0.4, exceptions are no
 longer dataclasses

---
 pint/delegates/txt_defparser/common.py |  9 ++-
 pint/errors.py                         | 98 +++++++++++++++++---------
 requirements.txt                       |  2 +-
 3 files changed, 72 insertions(+), 37 deletions(-)

diff --git a/pint/delegates/txt_defparser/common.py b/pint/delegates/txt_defparser/common.py
index ebdabc062..def901d88 100644
--- a/pint/delegates/txt_defparser/common.py
+++ b/pint/delegates/txt_defparser/common.py
@@ -12,7 +12,7 @@
 
 from __future__ import annotations
 
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 
 import flexparser as fp
 
@@ -20,7 +20,6 @@
 from ..base_defparser import ParserConfig
 
 
-@dataclass(frozen=True)
 class DefinitionSyntaxError(errors.DefinitionSyntaxError, fp.ParsingError):
     """A syntax error was found in a definition. Combines:
 
@@ -30,7 +29,11 @@ class DefinitionSyntaxError(errors.DefinitionSyntaxError, fp.ParsingError):
     and an extra location attribute in which the filename or reseource is stored.
     """
 
-    location: str = field(init=False, default="")
+    msg: str
+
+    def __init__(self, msg: str, location: str = ""):
+        self.msg = msg
+        self.location = location
 
     def __str__(self) -> str:
         msg = (
diff --git a/pint/errors.py b/pint/errors.py
index 59d3b4569..d1882dbdd 100644
--- a/pint/errors.py
+++ b/pint/errors.py
@@ -11,7 +11,6 @@
 from __future__ import annotations
 
 import typing as ty
-from dataclasses import dataclass, fields
 
 OFFSET_ERROR_DOCS_HTML = "https://pint.readthedocs.io/en/stable/user/nonmult.html"
 LOG_ERROR_DOCS_HTML = "https://pint.readthedocs.io/en/stable/user/log_units.html"
@@ -81,12 +80,10 @@ def def_err(self, msg: str):
         return DefinitionError(self.name, self.__class__, msg)
 
 
-@dataclass(frozen=False)
 class PintError(Exception):
     """Base exception for all Pint errors."""
 
 
-@dataclass(frozen=False)
 class DefinitionError(ValueError, PintError):
     """Raised when a definition is not properly constructed."""
 
@@ -94,69 +91,76 @@ class DefinitionError(ValueError, PintError):
     definition_type: type
     msg: str
 
+    def __init__(self, name: str, definition_type: type, msg: str):
+        self.name = name
+        self.definition_type = definition_type
+        self.msg = msg
+
     def __str__(self):
         msg = f"Cannot define '{self.name}' ({self.definition_type}): {self.msg}"
         return msg
 
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (self.name, self.definition_type, self.msg)
 
 
-@dataclass(frozen=False)
 class DefinitionSyntaxError(ValueError, PintError):
     """Raised when a textual definition has a syntax error."""
 
     msg: str
 
+    def __init__(self, msg: str):
+        self.msg = msg
+
     def __str__(self):
         return self.msg
 
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (self.msg,)
 
 
-@dataclass(frozen=False)
 class RedefinitionError(ValueError, PintError):
     """Raised when a unit or prefix is redefined."""
 
     name: str
     definition_type: type
 
+    def __init__(self, name: str, definition_type: type):
+        self.name = name
+        self.definition_type = definition_type
+
     def __str__(self):
         msg = f"Cannot redefine '{self.name}' ({self.definition_type})"
         return msg
 
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (self.name, self.definition_type)
 
 
-@dataclass(frozen=False)
 class UndefinedUnitError(AttributeError, PintError):
     """Raised when the units are not defined in the unit registry."""
 
-    unit_names: str | tuple[str, ...]
+    unit_names: tuple[str, ...]
+
+    def __init__(self, unit_names: str | ty.Iterable[str]):
+        if isinstance(unit_names, str):
+            self.unit_names = (unit_names,)
+        else:
+            self.unit_names = tuple(unit_names)
 
     def __str__(self):
-        if isinstance(self.unit_names, str):
-            return f"'{self.unit_names}' is not defined in the unit registry"
-        if (
-            isinstance(self.unit_names, (tuple, list, set))
-            and len(self.unit_names) == 1
-        ):
+        if len(self.unit_names) == 1:
             return f"'{tuple(self.unit_names)[0]}' is not defined in the unit registry"
         return f"{tuple(self.unit_names)} are not defined in the unit registry"
 
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (self.unit_names,)
 
 
-@dataclass(frozen=False)
 class PintTypeError(TypeError, PintError):
-    def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+    pass
 
 
-@dataclass(frozen=False)
 class DimensionalityError(PintTypeError):
     """Raised when trying to convert between incompatible units."""
 
@@ -166,6 +170,20 @@ class DimensionalityError(PintTypeError):
     dim2: str = ""
     extra_msg: str = ""
 
+    def __init__(
+        self,
+        units1: ty.Any,
+        units2: ty.Any,
+        dim1: str = "",
+        dim2: str = "",
+        extra_msg: str = "",
+    ) -> None:
+        self.units1 = units1
+        self.units2 = units2
+        self.dim1 = dim1
+        self.dim2 = dim2
+        self.extra_msg = extra_msg
+
     def __str__(self):
         if self.dim1 or self.dim2:
             dim1 = f" ({self.dim1})"
@@ -180,16 +198,25 @@ def __str__(self):
         )
 
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (
+            self.units1,
+            self.units2,
+            self.dim1,
+            self.dim2,
+            self.extra_msg,
+        )
 
 
-@dataclass(frozen=False)
 class OffsetUnitCalculusError(PintTypeError):
     """Raised on ambiguous operations with offset units."""
 
     units1: ty.Any
     units2: ty.Optional[ty.Any] = None
 
+    def __init__(self, units1: ty.Any, units2: ty.Optional[ty.Any] = None) -> None:
+        self.units1 = units1
+        self.units2 = units2
+
     def yield_units(self):
         yield self.units1
         if self.units2:
@@ -205,16 +232,19 @@ def __str__(self):
         )
 
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (self.units1, self.units2)
 
 
-@dataclass(frozen=False)
 class LogarithmicUnitCalculusError(PintTypeError):
     """Raised on inappropriate operations with logarithmic units."""
 
     units1: ty.Any
     units2: ty.Optional[ty.Any] = None
 
+    def __init__(self, units1: ty.Any, units2: ty.Optional[ty.Any] = None) -> None:
+        self.units1 = units1
+        self.units2 = units2
+
     def yield_units(self):
         yield self.units1
         if self.units2:
@@ -230,26 +260,28 @@ def __str__(self):
         )
 
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (self.units1, self.units2)
 
 
-@dataclass(frozen=False)
 class UnitStrippedWarning(UserWarning, PintError):
     msg: str
 
+    def __init__(self, msg: str):
+        self.msg = msg
+
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (self.msg,)
 
 
-@dataclass(frozen=False)
 class UnexpectedScaleInContainer(Exception):
-    def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+    pass
 
 
-@dataclass(frozen=False)
 class UndefinedBehavior(UserWarning, PintError):
     msg: str
 
+    def __init__(self, msg: str):
+        self.msg = msg
+
     def __reduce__(self):
-        return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
+        return self.__class__, (self.msg,)
diff --git a/requirements.txt b/requirements.txt
index c62365819..b63f8da99 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 platformdirs>=2.1.0
 typing_extensions>=4.0.0
 flexcache>=0.3
-flexparser>=0.3
+flexparser>=0.4

From a8bcb6ee1d0d61278bf17e332bc1aa473672e273 Mon Sep 17 00:00:00 2001
From: Hernan Grecco <hgrecco@gmail.com>
Date: Wed, 6 Nov 2024 23:35:48 -0300
Subject: [PATCH 15/18] ci: add Python 3.13 to github ci

---
 .github/workflows/ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 981f49e0c..dfebe5bdc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,7 +7,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
         numpy: [null, "numpy>=1.23,<2.0.0", "numpy>=2.0.0rc1"]
         uncertainties: [null, "uncertainties==3.1.6", "uncertainties>=3.1.6,<4.0.0"]
         extras: [null]

From 82801b3aa39528c62d20dbb834b51de42df9e03d Mon Sep 17 00:00:00 2001
From: Hernan Grecco <hgrecco@gmail.com>
Date: Thu, 7 Nov 2024 13:21:53 -0300
Subject: [PATCH 16/18] Preparing for release 0.24.3

---
 CHANGES | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index de1c3bccb..11c5e4372 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,8 +1,20 @@
 Pint Changelog
 ==============
 
-0.25 (unreleased)
------------------
+0.24.3 (2024-07-28)
+-------------------
+
+- add error for prefixed non multi units (#1998)
+- build: typing_extensions version
+- build: switch from appdirs to platformdirs
+- fix GenericPlainRegistry getattr type (#2045)
+- Replace references to the deprecated `UnitRegistry.default_format` (#2058)
+- fix: upgrade to flexparser>=0.4, exceptions are no longer dataclasses.
+  (required for Python 3.13)
+
+
+0.24.2 (2024-07-28)
+-------------------
 
 - Fix the default behaviour for pint-convert (cli) for importing uncertainties package (PR #2032, Issue #2016)
 - Added mu and mc as alternatives for SI micro prefix

From b6a6f68faf55bc4635c1cc1bcd567858ce8c418d Mon Sep 17 00:00:00 2001
From: Hernan Grecco <hgrecco@gmail.com>
Date: Thu, 7 Nov 2024 13:25:04 -0300
Subject: [PATCH 17/18] Preparing for release 0.24.4

---
 CHANGES | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index 11c5e4372..d4baea170 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,7 +1,7 @@
 Pint Changelog
 ==============
 
-0.24.3 (2024-07-28)
+0.24.4 (2024-11-07)
 -------------------
 
 - add error for prefixed non multi units (#1998)

From 861953eaa9d301e25c8135a61be37e01a9b00fad Mon Sep 17 00:00:00 2001
From: Hernan Grecco <hgrecco@gmail.com>
Date: Thu, 7 Nov 2024 13:26:43 -0300
Subject: [PATCH 18/18] Back to development: 0.25

---
 CHANGES | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/CHANGES b/CHANGES
index d4baea170..8b2fe9ec8 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,12 @@
 Pint Changelog
 ==============
 
+0.25.0 (unreleased)
+-------------------
+
+- Nothing changed yet
+
+
 0.24.4 (2024-11-07)
 -------------------