batch.spec

python = <<EOF

from batchutil import bazzinga

def foo():
    return f"foo: I am {self.name}"

def bar():
    return f"bar: I am {self.name}"
    
def baz():
    return bazzinga(self)
    
EOF

<batch>
  name p&l_calulator
  exec_str echo %foo()%
</batch>

batchutil.py

def bazzinga(batch):
    return f"baz: I am {batch.name}"

test.py

from apacheconfig import *
  
class BatchJobSpec:
    
    def __init__(self, pythoncode , batch):
        self.pythoncode = pythoncode
        self.name = batch.get("name")
        self._exec_str = batch.get("exec_str")
        self.exec()
    
    @property
    def exec_str(self):
        _exec = self._exec_str.split("%")
        
        for i in range(len(_exec)):
            if _exec[i].endswith('()'):
                f = self.__getattribute__(_exec[i][:-2])
                _exec[i] = f()
                return ''.join(_exec)
            
        
    def exec(self):
        locals_ = {'self': self}
        exec(self.pythoncode, locals_)
        
        _exec = []
        for attrib in locals_.keys():
            if not attrib in ['__builtins__', 'self']:
                print('__setattr__({})'.format(attrib))
                self.__setattr__(attrib, locals_[attrib])

with make_loader() as loader:
    config = loader.load('batch.spec')

batchjobspec = BatchJobSpec(config.get("python"), config.get("batch"))
print(batchjobspec.pythoncode)
print(batchjobspec.name)
print(batchjobspec.exec_str)
print(batchjobspec.baz())

@agrawalo

In batch.spec
still looks weird to me because self is sort of not available in this block. To make it bit more intuitive I guess changing this to something like below will look good and intuitive.

"def foo(batch):
return f"foo: I am {batch.name}""

I recommend the following, as it becomes a indirect member of the class and writing def function_name(self) are common.

def foo(self):
    return f"foo: I am {self.name}""

This needs to change the following line in def exec(self):

                _exec[i] = f(self)

The drawback are, you can't call batchjobspec.baz() any more you have to use batchjobspec.baz(batchjobspec).
You have to decide, more logic in batch.spec or in Python code itself.
And second, you have to use this with all def ... in batch.spec even if not needed.

this will result in changing following line
"exec_str echo %foo(self)%"

Yes, but this complicate finding function parameter in exec string

I actually made it a staticmethod. Please review the code https://gist.github.com/agrawalo/407caf4dcd44687fae6989f46b54975a