日拱一卒，一起来上伯克利的实验课，让你的Python溜起来开发者社区

日拱一卒，一起来上伯克利的实验课，让你的Python溜起来

>>> True and 13
______
>>> False or 0
______
>>> not 10
______
>>> not None
______
>>> True and 1 / 0 and False
______
>>> True or 1 / 0 or False
______
>>> True and 0
______
>>> False or 1
______
>>> 1 and 3 and 6 and 10 and 15
______
>>> 0 or False or 2 or 1 / 0
______
>>> not 0
______
>>> (1 + 1) and 1
______
>>> 1/0 or True
______
>>> (True or False) and False
______

>>> n = 3
>>> while n >= 0:
...     n -= 1
...     print(n)
______
>>> n = 4
>>> while n > 0:
...     n += 1
...     print(n)
______
>>> def go(n):
...     if n % 2 != 0:
...         print(n / 2)
...         return
...     while n > 0:
...         print(n)
...         n = n // 2
>>> go(4)
______
>>> go(5)
______
>>> zero = 2
>>> while zero != 0:
...    zero = zero // 2
...    print(zero)
______
>>> positive = 28
>>> while positive:
...    print("positive?")
...    positive -= 3
______
>>> positive = -9
>>> negative = -12
>>> while negative:
...    if positive:
...        print(negative)
...    positive += 3
...    negative += 3
______

>>> def square(x):
...     return x * x
>>> repeated(square, 2, 3)  # square(square(3)), or 3 ** 4
>>> repeated(square, 1, 4)  # square(4)
>>> repeated(square, 6, 2)  # big number
18446744073709551616
>>> def opposite(b):
...     return not b
>>> repeated(opposite, 4, True)
>>> repeated(opposite, 5, True)
False
>>> repeated(opposite, 631, 1)
False
>>> repeated(opposite, 3, 0)

def repeated(f, n, x):
    """Returns the result of composing f n times on x.
    "*** YOUR CODE HERE ***"
    if n == 1:
        return f(x)
    return f(repeated(f, n-1, x))

def repeated(f, n, x):
    """Returns the result of composing f n times on x.
    "*** YOUR CODE HERE ***"
    ret = x
    for _ in range(n):
        ret = f(ret)
    return ret

>>> sum_digits(10) # 1 + 0 = 1
>>> sum_digits(4224) # 4 + 2 + 2 + 4 = 12
>>> sum_digits(1234567890)

def sum_digits(n):
    """Sum all the digits of n.
    "*** YOUR CODE HERE ***"
    if n < 10:
        return n
    return sum_digits(n // 10) + n % 10

def sum_digits(n):
    """Sum all the digits of n.
    "*** YOUR CODE HERE ***"
    ret = 0
    while n > 0:
        ret += n % 10
        n //= 10
    return ret

>>> double_eights(8)
False
>>> double_eights(88)
>>> double_eights(2882)
>>> double_eights(880088)
>>> double_eights(12345)
False
>>> double_eights(80808080)
False

def double_eights(n):
    """Return true if n has two eights in a row.
    "*** YOUR CODE HERE ***"
    return '88' in str(n)

def double_eights(n):
    """Return true if n has two eights in a row.
    "*** YOUR CODE HERE ***"
    while n > 10:
        if n % 100 == 88:
            return True
        n //= 10
    return False

def double_eights(n):
    """Return true if n has two eights in a row.
    "*** YOUR CODE HERE ***"
    if n < 10:
        return False
    pref, suff = (n % 100) // 10, n % 10
    return (pref == 8 and suff == 8) or double_eights(n // 10)

>>> 0 or True
______
>>> not '' or not 0 and False
______
>>> 13 and False
______
>>> False or 1
______
>>> '' or 1 and 1/0
______
>>> not 0 and 12 or 0
______

>>> def xk(c, d):
...     if c == 4:
...         return 6
...     elif d >= 4:
...         return 6 + 7 + c
...     else:
...         return 25
>>> xk(10, 10)
______
>>> xk(10, 6)
______
>>> xk(4, 6)
______
>>> xk(0, 0)
______
>>> def how_big(x):
...     if x > 10:
...         print('huge')
...     elif x > 5:
...         return 'big'
...     elif x > 0:
...         print('small')
...     else:
...         print("nothin'")
>>> how_big(7)
______
>>> how_big(12)
______
>>> how_big(1)
______
>>> how_big(-1)
______
>>> def so_big(x):
...     if x > 10:
...         print('huge')
...     if x > 5:
...         return 'big'
...     if x > 0:
...         print('small')
...     print("nothin'")
>>> so_big(7)
______
>>> so_big(12)
______
>>> so_big(1)
______
>>> def ab(c, d):
...     if c > 5:
...         print(c)
...     elif c > 7:
...         print(d)
...     print('foo')
>>> ab(10, 20)
______
>>> def bake(cake, make):
...     if cake == 0:
...         cake = cake + 1
...         print(cake)
...     if cake == 1:
...         print(make)
...     else:
...         return cake
...     return make
>>> bake(0, 29)
______
>>> bake(1, "mashed potatoes")
______

def both_positive(x, y):
    """Returns True if both x and y are positive.
    >>> both_positive(-1, 1)
    False
    >>> both_positive(1, 1)
    return x and y > 0 # You can replace this line!

>>> falling(6, 3)  # 6 * 5 * 4
>>> falling(4, 0)
>>> falling(4, 3)  # 4 * 3 * 2
>>> falling(4, 1)  # 4

def falling(n, k):
    """Compute the falling factorial of n to depth k.
    "*** YOUR CODE HERE ***"
    ret = 1
    for i in range(n, n-k, -1):
        ret *= i
    return ret

def falling(n, k):
    """Compute the falling factorial of n to depth k.
    "*** YOUR CODE HERE ***"
    if k == 0:
        return 1
    return n * falling(n-1, k-1)

def guess_linear():
    """Guess in increasing order and return the number of guesses."""
    prompt_for_number(LOWER, UPPER)
    num_guesses = 1
    guess = LOWER
    "*** YOUR CODE HERE ***"
    return num_guesses

def guess_linear():
    """Guess in increasing order and return the number of guesses."""
    prompt_for_number(LOWER, UPPER)
    num_guesses = 1
    guess = LOWER
    "*** YOUR CODE HERE ***"
    while guess <= UPPER:
        correct = is_correct(guess)
        if correct:
            break
        guess += 1
        num_guesses += 1
    return num_guesses

def guess_binary():
    """Return the number of attempted guesses. Implement a faster search
    algorithm that asks the user whether a guess is less than or greater than
    the correct number.
    Hint: If you know the guess is greater than the correct number, then your
    algorithm doesn't need to try numbers that are greater than guess.
    prompt_for_number(LOWER, UPPER)
    num_guesses = 1
    lower, upper = LOWER, UPPER

日拱一卒，一起来上伯克利的实验课，让你的Python溜起来

日拱一卒，一起来上伯克利的实验课，让你的Python溜起来

What Would Python Display (Part 1)?

Q1: WWPD: Veritasiness

Q2: WWPD: Loops

Coding Practice

Q3: Repeated

答案

Q4: Sum Digits

答案

Q5: Double Eights

答案

附加题

What Would Python Display (Part 2)?

Q6: WWPD: Truthiness

Q7: WWPD: What If?

More Coding Practice

Q8: Fix the Bug

答案

Q9: Falling Factorial

答案

I Want to Play a Game

Q10: Guess Linear

答案

Q11: Guess Binary