Python class written in string to literal object

Question

I am trying to save a class written in string format to a database, then read this and load the class as literal class.

How can I do this?

test = """
class Test:
    def __init__(self, test_name):
        self.test_name = test_name
    
    def print_name(self):
        print(self.test_name)
"""

Test = eval(test)
test_obj = Test(test_name='test1')

It would be better together if I also know how to save the object instance in string format since I will save the instance to the database as well, like saving pickle.

Many thanks.

Answer 1

Almost a duplicate but I had to combine two answers. If you have your class saved in a file - which you probably have - you are in luck:

According to here you want to use the inspect.getsource .

According to here you will then need to call the exec function on the string to retrieve the saved class.

Putting things together:

import inspect

class Test:
    def __init__(self):
        self.a = 1
    def print(self):
        print(self.a)

text = inspect.getsource(Test)
exec(text)

As for retrieving a code of a class that is not saved in the file I didn't find a way and the first linked question's answer suggests that there isn't any.