Revert Cython upgrade (#54497)

* Revert "CLN: Cython 3 cleanups (#54482)"

This reverts commit a936863.

* Revert "DEPS: Bump cython 3.0 (#54335)"

This reverts commit 4cf63ea.

Author: phofl

asv_bench/asv.conf.json

@@ -41,7 +41,7 @@
     // pip (with all the conda available packages installed first,
     // followed by the pip installed packages).
     "matrix": {
-        "Cython": ["3.0.0"],
+        "Cython": ["0.29.33"],
         "matplotlib": [],
         "sqlalchemy": [],
         "scipy": [],

ci/deps/actions-310.yaml

@@ -6,7 +6,7 @@ dependencies:
 
   # build dependencies
   - versioneer[toml]
-  - cython>=3.0.0
+  - cython>=0.29.33
   - meson[ninja]=1.0.1
   - meson-python=0.13.1
 

ci/deps/actions-311-downstream_compat.yaml

@@ -7,7 +7,7 @@ dependencies:
 
   # build dependencies
   - versioneer[toml]
-  - cython>=3.0.0
+  - cython>=0.29.33
   - meson[ninja]=1.0.1
   - meson-python=0.13.1
 

ci/deps/actions-311-pyarrownightly.yaml

@@ -7,7 +7,7 @@ dependencies:
   # build dependencies
   - versioneer[toml]
   - meson[ninja]=1.0.1
-  - cython>=3.0.0
+  - cython>=0.29.33
   - meson-python=0.13.1
 
   # test dependencies

ci/deps/actions-311.yaml

@@ -6,7 +6,7 @@ dependencies:
 
   # build dependencies
   - versioneer[toml]
-  - cython>=3.0.0
+  - cython>=0.29.33
   - meson[ninja]=1.0.1
   - meson-python=0.13.1
 

ci/deps/actions-39-minimum_versions.yaml

@@ -8,7 +8,7 @@ dependencies:
 
   # build dependencies
   - versioneer[toml]
-  - cython>=3.0.0
+  - cython>=0.29.33
   - meson[ninja]=1.0.1
   - meson-python=0.13.1
 

ci/deps/actions-39.yaml

@@ -6,7 +6,7 @@ dependencies:
 
   # build dependencies
   - versioneer[toml]
-  - cython>=3.0.0
+  - cython>=0.29.33
   - meson[ninja]=1.0.1
   - meson-python=0.13.1
 

ci/deps/actions-pypy-39.yaml

@@ -9,7 +9,7 @@ dependencies:
 
   # build dependencies
   - versioneer[toml]
-  - cython>=3.0.0
+  - cython>=0.29.33
   - meson[ninja]=1.0.1
   - meson-python=0.13.1
 

ci/deps/circle-310-arm64.yaml

@@ -6,7 +6,7 @@ dependencies:
 
   # build dependencies
   - versioneer[toml]
-  - cython>=3.0.0
+  - cython>=0.29.33
   - meson[ninja]=1.0.1
   - meson-python=0.13.1
 

doc/source/whatsnew/v2.1.0.rst

@@ -873,7 +873,6 @@ Other
 - Bug in :meth:`Series.memory_usage` when ``deep=True`` throw an error with Series of objects and the returned value is incorrect, as it does not take into account GC corrections (:issue:`51858`)
 - Bug in :meth:`period_range` the default behavior when freq was not passed as an argument was incorrect(:issue:`53687`)
 - Fixed incorrect ``__name__`` attribute of ``pandas._libs.json`` (:issue:`52898`)
-- The minimum version of Cython needed to compile pandas is now ``3.0.0`` (:issue:`54335`)
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_210.contributors: