gistfile1.py

# https://company.yandex.ru/job/vacancies/dev_pyth_transport.xml

from itertools import chain
def f(l1, l2):
    def gen():
        while True:
            yield None
    return dict(zip(l1, chain(l2, gen())))

assert(f([1,2,3,4,5,6],['a','b','c']) ==
{1: 'a', 2: 'b', 3: 'c', 4: None, 5: None, 6: None})

#---------------------------
#---------------------------

import re

def check_psw1(psw):
    r = re.compile(r"""(?x)(?i)
      ^
        (([a-zA-Z])
        ||
        ([a-zA-Z][a-zA-Z0-9\.-]{0,18}[a-zA-Z0-9]))
      $""")
    return bool(r.match(psw))

# --
from itertools import chain
from functools import reduce
import string

def check_psw2(psw):
    return reduce(
        lambda a,i: a and i,
        chain(
            [len(psw) <= 20],
            [i in set("".join(
                (string.ascii_letters))
                ) for i in psw[0]],
            [i in set("".join(
                (string.ascii_letters, string.digits, ".-"))
                ) for i in psw[:]],
            [i in set("".join(
                (string.ascii_letters, string.digits,))
                ) for i in psw[-1]]),
        True)

psw_true = ['a', 'A', 'aa.-a', 'aa123', 'a'*20, ]
psw_false = ['1', '.', '$aa', 'a_', '-aaa', 'aa.#a', 'a'*21, 'aaa.', 'aaa-']

for ii in psw_true:
    assert(check_psw1(ii))
    assert(check_psw2(i))

for ii in psw_false:
    assert(not check_psw1(ii))
    assert(not check_psw2(ii))

map(None, a, b)