Module trase.tools.etl.source

Classes

class GetSource (*args, **kwargs)

Fetches the source code of the class on instantiation.

Once a Python class has been instantiated, it can be difficult to reconstruct the source code. inspect.getsource will locate the original file and load the text from there, but that assumes that the file hasn't changed between instantiating the class and calling the function. Third-party libraries like dill are cleverer, but still don't handle re-loaded code very well. Python gives you the ability to access the byte code, but this carries less informational content than the source code.

This metaclass fetches the source code immediately after the class was instantiated. Use it as follows:

# my_module.py

class MyClass(metaclass=GetSource):
    pass

Then you can access the source code like this:

import my_module
my_module.MyClass._source

Crucially, the source code will also be updated should you reload the module using importlib.reload. We do not attempt to capture interactive code (i.e. in module main): in this case the source code will be None.

Ancestors

• builtins.type

Subclasses

• trase.tools.etl.processors._Meta