How to Sorted and display the Subclasses of BaseException

[Fernando_7obink]

I have a task from the online course that i enrolled free recently , can anyone help me for sorting the printout from the line code as follow :

def printExcTree(thisclass, nest = 0):
    if nest > 1:
        print("   |" * (nest - 1), end="")
    if nest > 0:
        print("   +---", end="")

    print(thisclass.__name__)

    for subclass in thisclass.__subclasses__():
        printExcTree(subclass, nest + 1)

printExcTree(BaseException)

and here is the output :

Output:
BaseException
   +---Exception
   |   +---TypeError
   |   +---StopAsyncIteration
   |   +---StopIteration
   |   +---ImportError
   |   |   +---ModuleNotFoundError
   |   |   +---ZipImportError
   |   +---OSError
   |   |   +---ConnectionError
   |   |   |   +---BrokenPipeError
   |   |   |   +---ConnectionAbortedError
   |   |   |   +---ConnectionRefusedError
   |   |   |   +---ConnectionResetError
   |   |   +---BlockingIOError
   |   |   +---ChildProcessError
   |   |   +---FileExistsError
   |   |   +---FileNotFoundError
   |   |   +---IsADirectoryError
   |   |   +---NotADirectoryError
   |   |   +---InterruptedError
   |   |   +---PermissionError
   |   |   +---ProcessLookupError
   |   |   +---TimeoutError
   |   |   +---UnsupportedOperation
   |   |   +---herror
   |   |   +---gaierror
   |   |   +---timeout
   |   |   +---Error
   |   |   |   +---SameFileError
   |   |   +---SpecialFileError
   |   |   +---ExecError
   |   |   +---ReadError
   |   +---EOFError
   |   +---RuntimeError
   |   |   +---RecursionError
   |   |   +---NotImplementedError
   |   |   +---_DeadlockError
   |   |   +---BrokenBarrierError
   |   +---NameError
   |   |   +---UnboundLocalError
   |   +---AttributeError
   |   +---SyntaxError
   |   |   +---IndentationError
   |   |   |   +---TabError
   |   +---LookupError
   |   |   +---IndexError
   |   |   +---KeyError
   |   |   +---CodecRegistryError
   |   +---ValueError
   |   |   +---UnicodeError
   |   |   |   +---UnicodeEncodeError
   |   |   |   +---UnicodeDecodeError
   |   |   |   +---UnicodeTranslateError
   |   |   +---UnsupportedOperation
   |   +---AssertionError
   |   +---ArithmeticError
   |   |   +---FloatingPointError
   |   |   +---OverflowError
   |   |   +---ZeroDivisionError
   |   +---SystemError
   |   |   +---CodecRegistryError
   |   +---ReferenceError
   |   +---BufferError
   |   +---MemoryError
   |   +---Warning
   |   |   +---UserWarning
   |   |   +---DeprecationWarning
   |   |   +---PendingDeprecationWarning
   |   |   +---SyntaxWarning
   |   |   +---RuntimeWarning
   |   |   +---FutureWarning
   |   |   +---ImportWarning
   |   |   +---UnicodeWarning
   |   |   +---BytesWarning
   |   |   +---ResourceWarning
   |   +---error
   |   +---Verbose
   |   +---Error
   |   +---TokenError
   |   +---StopTokenizing
   |   +---Empty
   |   +---Full
   |   +---_OptionError
   |   +---TclError
   |   +---SubprocessError
   |   |   +---CalledProcessError
   |   |   +---TimeoutExpired
   |   +---Error
   |   |   +---NoSectionError
   |   |   +---DuplicateSectionError
   |   |   +---DuplicateOptionError
   |   |   +---NoOptionError
   |   |   +---InterpolationError
   |   |   |   +---InterpolationMissingOptionError
   |   |   |   +---InterpolationSyntaxError
   |   |   |   +---InterpolationDepthError
   |   |   +---ParsingError
   |   |   |   +---MissingSectionHeaderError
   |   +---InvalidConfigType
   |   +---InvalidConfigSet
   |   +---InvalidFgBg
   |   +---InvalidTheme
   |   +---EndOfBlock
   |   +---BdbQuit
   |   +---error
   |   +---_Stop
   |   +---PickleError
   |   |   +---PicklingError
   |   |   +---UnpicklingError
   |   +---_GiveupOnSendfile
   |   +---error
   |   +---LZMAError
   |   +---RegistryError
   |   +---ErrorDuringImport
   +---GeneratorExit
   +---SystemExit
   +---KeyboardInterrupt

what i want to do is to sort every subclass depend on his first letter alphabetly and the subclass from every subclass follow the same rule...

[buran]

So, what have you tried? Because, what's the point if you don't try for yourself.

[Gribouillis]

Try this perhaps

for subclass in sorted(thisclass.__subclasses__()):

Also have a look at module asciitree in pypi.

[Fernando_7obink]

So, what have you tried? Because, what's the point if you don't try for yourself.

i have done few things e.g.
try to sort the subclass first by sorting the for loop as follow

for subclass in sorted(thisclass.__subclasses__()):

, but it cant work because the sorted() only work on string or number type

then i try to create a list that will consist of the subclass name that already converted to "string" type, so next i can sort that list, then print it, so i try this code

def printExcTree(thisclass, nest = 0):
    if nest > 1:
        print("   |" * (nest - 1), end="")
    if nest > 0:
        print("   +---", end="")

    print(thisclass.__name__)
    
    a = []
    for subclass in thisclass.__subclasses__():
        a.append(subclass.__name__)
        for srt_subclass in a :
            printExcTree(srt_subclass, nest + 1)

printExcTree(BaseException)

and cant work because when it comes to recursion

printExcTree(srt_subclass, nest + 1)

the first parameter pass a str type, meanwhile the

print(thisclass.__name__)

only can work on class type. Is there any way to change the str type becoming a class type e.g. ValueError become "ValueError" then i can change it again "valueError" become ValueError

[buran]

it cant work because the sorted() only work on string or number type

do you know that sorted() takes optional key argument? it takes a function that is applied to each element and result is used for the sort.

[Fernando_7obink]

it cant work because the sorted() only work on string or number type

do you know that sorted() takes optional key argument? it takes a function that is applied to each element and result is used for the sort.

Do you mean like this ?

a = ("h", "b", "a", "c", "f", "d", "e", "g")
x = sorted(a, reverse=True)
print(x)

[buran]

No, not reverse, but key

for subclass in sorted(thisclass.__subclasses__(), key=str):

from the docs

key specifies a function of one argument that is used to extract a comparison key from each element in iterable (for example, key=str.lower). The default value is None (compare the elements directly).

[Gribouillis]

You could also try key = lambda klass: klass.__name__

[Fernando_7obink]

No, not reverse, but key

for subclass in sorted(thisclass.__subclasses__(), key=str):

from the docs

key specifies a function of one argument that is used to extract a comparison key from each element in iterable (for example, key=str.lower). The default value is None (compare the elements directly).

at last i can get a right answer, thank you....
can i ask more ... about the 'str' in key ... how does it work ? does it mean the key = str will take each element and change them to str type data and compare them ?
because point to my case, the

thisclass.__subclasses__()

will give an output list, for each element is a 'class type'

[buran]

about the 'str' in key ... how does it work ? does it mean the key = str will take each element and change them to str type data and compare them ?

yes, I think it's pretty clear from the docs I quoted in my answer. It will apply function supplied as key on each element in the list and use the result to compare/order the element, in this case the function is str() - a built-in function, in the @Gribouillis example - a lambda function (that is anonymous function) which takes one argument klass (i.e. one element) and returns klass.__name__ attribute (which is also a string).