Functions that should be in the python builtins module

builtins.py

from enum import Enum

def enum(name, attrs=None):
    '''enum generator function
    Creates an Enum type. attrs can be: set, list, tuples or a dictionary.
    The behavior is as follows:
        - dictionaries and lists/tuples of the form [(name, key), (name2, key2), ...] will behave
            as expected. (dictionaries will have their items() method called
        - sets will be converted to zip(sorted(attrs), range(len(attrs)))
        - lists/tuples without embeded tuples will do the same without sorting
    
    Can be called in two forms:
        enum(name, attrs)
        OR
        enum(attrs)  # name will == 'enum'
    '''
    if attrs is None:
        # use default name, attrs becomes first argument
        name, attrs = 'enum', name
    if isinstance(attrs, dict):
        attrs = attrs.items()
    elif isinstance(attrs, set):
        attrs = zip(sorted(attrs), range(len(attrs)))
    elif not isinstance(attrs[0], (tuple, list)):
        attrs = zip(attrs, range(len(attrs)))
    return Enum(name, attrs)


def isiter(obj, exclude=(str, bytes, bytearray)):
    '''Returns True if object is an iterator.
    Returns False for str, bytes and bytearray objects
    by default'''
    return (False if isinstance(obj, exclude)
            else True if hasattr(obj, '__iter__')
            else False)

# python3
def encode(data, encoding="utf-8", errors="strict"):
    '''Always outputs bytes if possible'''
    if isinstance(data, (bytes, bytearray)):
        return bytes(data)
    elif hasattr(data, 'encode'):
        return data.encode(encoding, errors)
    elif hasattr(data, 'decode'):
        return(decode(encode(data, encoding, errors), encoding, errors))
    else:
        raise TypeError("Cannot encode data: {}".format(data))
 
def decode(data, encoding="utf-8", errors="strict"):
    '''Always outputs str if possible'''
    if isinstance(data, str):
        return data
    elif hasattr(data, 'decode'):
        return data.decode(encoding, errors)
    elif hasattr(data, 'encode'):
        return(encode(decode(data, encoding, errors), encoding, errors))
    else:
        raise TypeError("Cannot decode data: {}".format(data))