Use Python 3.8 features and cleanup 3.7 branches (PaddlePaddle#59871)

* Use Python 3.8 features and cleanup 3.7 branches

* fix version compare

Author: SigureMo

paddle/fluid/pir/dialect/op_generator/api_gen.py

@@ -594,8 +594,11 @@ def _gen_check_data_type(self, op_info, op_name):
             for name in op_info.input_name_list[::-1]:
                 type = mapping_input_name_to_type[name]
                 optional = mapping_input_name_to_optional[name]
-                function_name = mapping_type_to_function_name.get(type, None)
-                if function_name is None:
+                if (
+                    function_name := mapping_type_to_function_name.get(
+                        type, None
+                    )
+                ) is None:
                     continue
 
                 if optional == 'false':
@@ -635,8 +638,9 @@ def _gen_check_data_type(self, op_info, op_name):
             if name not in mapping_name_to_type:
                 return ""
             type = mapping_name_to_type[name]
-            function_name = mapping_type_to_function_name.get(type, None)
-            if function_name is None:
+            if (
+                function_name := mapping_type_to_function_name.get(type, None)
+            ) is None:
                 return ""
             return CHECK_DATA_TYPE_TEMPLATE.format(
                 function=function_name,

python/paddle/base/core.py

@@ -41,8 +41,7 @@
         # Note: from python3.8, PATH will not take effect
         # https://github.com/python/cpython/pull/12302
         # Use add_dll_directory to specify dll resolution path
-        if sys.version_info[:2] >= (3, 8):
-            os.add_dll_directory(third_lib_path)
+        os.add_dll_directory(third_lib_path)
 
 except ImportError as e:
     if os.name == 'nt':

python/paddle/base/executor.py

@@ -770,7 +770,7 @@ def _can_use_interpreter_core(program, place):
     return True
 
 
-@lru_cache()
+@lru_cache
 def _warning_once(msg):
     logging.warning(msg)
 

python/paddle/jit/dy2static/pir_partial_program.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import itertools
+from functools import cached_property
 
 import numpy as np
 
@@ -33,20 +34,6 @@
 __all__ = []
 
 
-class cached_property:
-    """
-    Descriptor to implement lazy initialization of property.
-    """
-
-    def __init__(self, function):
-        self.function = function
-
-    def __get__(self, instance, cls):
-        val = self.function(instance)
-        setattr(instance, self.function.__name__, val)
-        return val
-
-
 class NestSequence:
     """
     A wrapper class that easily to flatten and restore the nest structure of

test/legacy_test/test_gast_with_compatibility.py

@@ -153,7 +153,7 @@ def foo(x_new, y_new):
     #
     # More information please refer to:
     # https://github.com/serge-sans-paille/gast/issues/49
-    if sys.version_info < (3, 8):
+    if sys.version_info >= (3, 9):
 
         def test_with(self):
             """