Investigate the subtypes of various python callables

callable_subtypes.py

"""
Code that prints this table (meant to study the type-differences of different callables):

```
                                MethodType  FunctionType  has_self  qualname_levels  dunders
name                                                                                        
class method                          True         False      True                2       27
instance method                      False          True     False                2       35
static method                        False          True     False                2       35
"instantiated" class method           True         False      True                2       27
"instantiated" instance method        True         False      True                2       27
"instantiated" static method         False          True     False                2       35
"plain" function                     False          True     False                1       35
lambda                               False          True     False                1       35
```

See [this stackoverflow question](https://stackoverflow.com/questions/61919480/subtypes-of-python-callables-how-to-tell-if-an-object-is-a-class-instance-sta) I posted about it.
"""

def f(): ...
    
class X:
    @classmethod
    def c(cls): ...
    
    @staticmethod
    def s(): ...
    
    #instance method
    def i(self): ...

from types import MethodType, FunctionType

d = {
    'class method': X.c,
    'instance method': X.i,
    'static method': X.s,
    '"instantiated" class method': X().c,
    '"instantiated" instance method': X().i,
    '"instantiated" static method': X().s,
    '"plain" function': f,
    'lambda': lambda: None
}

t = list()
for name, obj in d.items():
    t.append({'name': name, 
              'MethodType': isinstance(obj, MethodType), 
              'FunctionType': isinstance(obj, FunctionType), 
              'has_self': hasattr(obj, '__self__'),
              'qualname_levels': len(obj.__qualname__.split('.')),
              'dunders': len(dir(obj)),
             })
print(pd.DataFrame(t).set_index('name').to_string())