Chained list operations in Python

l.py

class L(object):
    def __init__(self, iterable):
        self.value = iterable
    def map(self, fn):
        self.value = map(fn, self.value)
        return self
    def join(self, s):
        self.value = s.join(self.value)
        return self
    
    # that doesn't delegate every mechanic to self.value,
    # do we need to implement every __special_method__?...
    def __coerce__(self, other):
        return type(other)(self.value)
        
# presumed usage:
L(some_List).map(some_function).join("some string")