def myiter(other_iter):
    yield "First element"
    for item in other_iter:
        yield item
    yield "Last element"

def myiter(other_iter):
    yield "First element"
    yield_items_from(other_iter)
    yield "Last element"

new_iter = itertools.chain(['prefix item'], old_iter, appended_iter)

import itertools

for item in itertools.chain(["First element"],other_iter,["Last element"]):
    ...

import itertools as it

def bincounter(iterable):
    counter=it.count()
    for elt in iterable:
        for c in counter:
            if c < elt:
                yield 0
            else:
                yield 1
                break

other_iter=iter([1,4,5,7])
print(list(bincounter(other_iter)))
# [0, 1, 0, 0, 1, 1, 0, 1]

other_iter = [1,4,5,7]

def flags( items ):
    c = 0
    for this in items:
        while c < this:
            yield 0
            c += 1
        yield 1

print list(flags(other_iter))

def ch(*iters):
    for it in iters:
        for elem in it:
            yield elem

s1=["First element"]
s2=['middle 1', 'middle 2', 'middle 3']
s3=["last element"]

for i in ch(s1,s2,s3):
    print i

def in_l(l):
    count = 0
    while count<=max(l):
        if count in l:
            count += 1
            yield 1
        else:
            count += 1
            yield 0

print list(in_l([1,4,5,7]))

def myiter(other_iter):
    yield "First element"
    yield from other_iter
    yield "Last element"