"""
open/dulcinea/lib/sort.py
"""
from qpy import stringify

def str_sort(seq):
    """(seq) -> []

    Sort 'seq' by the str() of each element.
    """
    return sorted(seq, key=stringify)

def lexical_sort(seq):
    """(seq) -> []

    Sort 'seq' by the stringify().lower() of each element.
    """
    def stringify_lower(x):
        return stringify(x).lower()
    return sorted(seq, key=stringify_lower)

def attr_sort(seq, attr):
    """(seq, attr : string) -> []

    Sort 'seq' by the attribute 'attr' of each element.
    """
    attr = str(attr)
    def get_attr(v):
        return getattr(v, attr)
    return sorted(seq, key=get_attr)

def method_sort(seq, method):
    """(seq, method : string) -> []

    Sort 'seq' by the result of calling method 'method' on each element.
    """
    method = str(method)
    def meth(v):
        return getattr(v, method)()
    return sorted(seq, key=meth)