将SConstruct移植到Python 3

问题描述

2020年使SConstruct Python 3兼容的最佳实践是什么？

例如，运行旧的SConstruct会出现这样的错误。

✗ python ~/scons/scripts/scons.py
scons: Reading sconscript files ...
  File "/home/techtonik/Folding@home/fah-control/SConstruct",line 17

    except Exception,e:

                    ^

SyntaxError: invalid Syntax

解决方法

2to3或modernize应该有所帮助。只是Python语法有问题。

2to3是Python随附的，也可以作为Python模块执行：

python -m lib2to3 -w SConstruct

这里是2to3建议的补丁，看起来很小：

RefactoringTool: Refactored SConstruct
--- SConstruct  (original)
+++ SConstruct  (refactored)
@@ -3,8 +3,8 @@
 env = Environment(ENV = os.environ)
 try:
     env.Tool('config',toolpath = [os.environ.get('CBANG_HOME')])
-except Exception,e:
-    raise Exception,'CBANG_HOME not set?\n' + str(e)
+except Exception as e:
+    raise Exception('CBANG_HOME not set?\n' + str(e))
 
 env.CBLoadTools('packager run_distutils osx fah-client-version')
 env.CBAddVariables(
@@ -14,7 +14,7 @@
 # Version
 try:
     version = env.FAHClientVersion()
-except Exception,e:
+except Exception as e:
     print(e)
     version = '0.0.0'
     env.Replace(PACKAGE_VERSION = version)
RefactoringTool: Files that need to be modified:
RefactoringTool: SConstruct