Object Introspection Tool

introspector.py

import inspect
import itertools
import reprlib
from sorted_set import SortedSet


def full_sig(method):
    try:
        return method.__name__ + str(inspect.signature(method))
    except ValueError:
        return method.__name__ + '(...)'


def brief_doc(obj):
    doc = obj.__doc__
    if doc is not None:
        lines = doc.splitlines()
        if len(lines) > 0:
            return lines[0]
    return


def print_table(rows_of_columns, *headers):
    num_columns = len(rows_of_columns[0])
    num_headers = len(headers)
    if len(headers) != num_columns:
        raise TypeError("Expected {} header arguments, got {}".format(num_columns, num_headers))
    rows_of_columns_with_header = itertools.chain([headers], rows_of_columns)
    columns_of_rows = list(zip(*rows_of_columns_with_header))
    column_widths = [max(len(column_row if column_row is not None else "None")
                         for column_row in column)
                     for column in columns_of_rows]
    column_specs = ('{{:{w}}}'.format(w=width) for width in column_widths)
    format_spec = ' '.join(column_specs)
    print(format_spec.format(*headers))
    rules = ('-' * width for width in column_widths)
    print(format_spec.format(*rules))
    for row in rows_of_columns:
        print(format_spec.format(*(str(word) for word in row)))


def dump(obj):
    print('Type')
    print('====')
    print(type(obj))
    print()

    print('Documentation')
    print('==============')
    print(inspect.getdoc(obj))
    print()

    print('Attributes')
    print('===========')
    all_attr_names = SortedSet(dir(obj))
    method_names = SortedSet(filter(lambda attr_name: callable(getattr(obj, attr_name)), all_attr_names))
    assert method_names <= all_attr_names
    attr_names = all_attr_names - method_names
    attr_names_and_values = [(name, reprlib.repr(getattr(obj, name))) for name in attr_names]
    print_table(attr_names_and_values, "Name", "Value")
    print()

    print('Methods')
    print('========')
    methods = (getattr(obj, method_name) for method_name in method_names)
    method_names_and_doc = [(full_sig(method), brief_doc(method)) for method in methods]
    print_table(method_names_and_doc, "Name", "Description")
    print()


if __name__ == '__main__':
    dump(int(7))