# list generate
[x for x in range(10)]

# loop through string
for c in "oklahoma":
    print(2*c)

# conditional generate
[2*c for c in "oklahoma" if c != "o"]

# string range
"oklahoma"[3:6]
"oklahoma"[-2:]

def squares():
    n = 0
    while(True):
        yield n*n
        n += 1

def cubes():
    n = 0
    while (True):
        yield n*n*n
        n += 1

for i in squares():
    if i > 100:
        break
    print(i)

def test_nice(n):
    for i in squares():
        if i > n:
            break
        for j in cubes():
            if i+j > n:
                break
            if i+j == n:
                return i,j
    return 0,0

def is_prime(n):
    if n < 2:
        return False
    if n == 2:
        return True
    else:
        i = 2
        while i*i <= n:
            if n % i == 0:
                return False
            i += 1
        return True


def Primes():
    yield 2
    i = 3
    while (True):
        if is_prime(i):
            yield i
        i += 2

l = [x for x in range(100) if is_prime(x)]


def Collatz(n):
    while (True):
        yield n
        if n == 1:
            break
        elif n % 2 == 0:
            n = n // 2
        else:
            n = 3 * n + 1

def applyf(f, a):
    return f(a)

def root_f(f, n, low, upper):
    if low >= upper - 1:
        if f(upper) == n:
            return upper
        else:
            return low
    mid = (low + upper) // 2

    if f(mid) >= n:
        return root_f(f, n, low, mid)
    else:
        return root_f(f, n, mid, upper)