[CodeStyle] init flake8 configs (#45943)

.editorconfig

+# EditorConfig is a cross-editor configuration file
+# that helps to unify code styles for multiple
+# developers collaborative projects.
+# See more at https://editorconfig.org/
+
+root = true
+
+[*]
+indent_style = space
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.{c,cc,cxx,cpp,cu,cuh,h,hpp,hxx,kps}]
+indent_size = 2
+
+[*.{py,java,r}]
+indent_size = 4
+
+[Dockerfile.*]
+indent_size = 4
+
+[.flake8]
+indent_size = 4
+
+[*.go]
+indent_style = tab
+indent_size = 4

.flake8

+[flake8]
+select = C,E,F,W
+exclude = ./build
+ignore =
+    # E, see https://pycodestyle.pycqa.org/en/latest/intro.html#error-codes
+    E101,E121,E122,E123,E124,E125,E126,E127,E128,E129,E131,
+    E201,E202,E203,E221,E225,E226,E228,E231,E241,E251,E261,E262,E265,E266,E271,E272,E275,
+    E301,E302,E303,E305,E306,
+    E401,E402,
+    E501,E502,
+    E701,E711,E712,E713,E714,E721,E722,E731,E741,
+
+    # F, see https://flake8.pycqa.org/en/latest/user/error-codes.html
+    F401,F402,F403,F404,F405,
+    F522,F523,F524,F541,
+    F601,F631,F632,
+    F811,F821,F823,F841,
+
+    # W, see https://pycodestyle.pycqa.org/en/latest/intro.html#error-codes
+    W191,
+    W503,W504
+    W601,W605

.pre-commit-config.yaml

@@ -22,6 +22,10 @@ repos:
                 python/paddle/fluid/tests/unittests/dygraph_to_static/test_error.py|
                 python/paddle/fluid/tests/unittests/dygraph_to_static/test_origin_info.py
             )$
+-   repo: https://github.com/PyCQA/flake8
+    rev: 4.0.1
+    hooks:
+    -   id: flake8
 -   repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.1.0
     hooks: