Pretty string printer for nested, circular data structures.

PrettyString.py

class PrettyStringCreation:
    def pstr_list(self, l: list, opts: dict):
        plist = []
        for e in l:
            plist.append(self.pstr(e, opts))
        return '[' + ', '.join(plist) + ']'

    def pstr_dict(self, d: dict, opts: dict):
        sl = []
        for k in d.keys():
            if k in set(opts.keys()):
                sl.append(self.pstr(k) + ': ' + self.pstr(d[k], opts[k]))
            else:
                sl.append(self.pstr(k) + ': ' + self.pstr(d[k]))
        return '{' + ', '.join(sl) + '}'

    def pstr_other(self, obj, opts: dict):
        d: dict = obj.__dict__
        if type(opts) == str:
            return d[opts]
        sl = []
        for k in d.keys():
            if k in set(opts.keys()):
                v = d[k]
                if type(v) == dict:
                    sl.append(self.pstr(k) + ': ' + self.pstr(v, opts[k]))
                elif type(v) == list:
                    l = []
                    for e in v:
                        l.append(self.pstr(e, opts[k]))
                    sl.append(self.pstr(k) + ': ' + '[' + ', '.join(l) + ']')
                else:
                    sl.append(self.pstr(k) + ': ' + self.pstr(v, opts[k]))
            else:
                sl.append(self.pstr(k) + ': ' + self.pstr(d[k]))
        return obj.__class__.__name__ + '(' + ', '.join(sl) + ')'

    def pstr(self, obj, opts=None) -> str:
        if opts is None:
            opts = {}
        t = type(obj)
        if obj is None:
            return "None"
        elif t == int:
            return obj.__str__()
        elif t == float:
            return obj.__str__()
        elif t == str:
            return obj.__str__()
        elif t == list:
            return self.pstr_list(obj, opts)
        elif t == dict:
            return self.pstr_dict(obj, opts)
        else:
            return self.pstr_other(obj, opts)


def pretty_print(obj, **kwargs):
    print(PrettyStringCreation().pstr(obj, kwargs))