ソフトウェアエンジニアの技術ブログ：Software engineer tech blog

from functools import update_wrapper

def genseq(x, y, Ns):
	def n_ary_f(x, *args):
		return x if not args else f(x, n_ary_f(*args))
	update_wrapper(n_ary_f, f)
	return n_ary_f

def seq(x, y): return ('seq', x, y)

>>> help(seq)
Help on function n_ary_f in module __main__:

n_ary_f(x, *args)

@decorator
def trace(f):
	indent = ' '
	def _f(*args):
		signature = '%s(%s)' % (f.__name__, ', '.join(map(repr, args)))
		print '%s--> %s' % (trace.level*indent, signature)
		trace.level += 1
		try:
			print '%s<-- %s === %s' % ((trace.level-1)*indent,
									signature, result)

			finally:
				trace.level -= 1
			return result
		trace.level = 0
		return _f
&#91;/python&#93;

&#91;python&#93;
G = grammar(r"""
Exp => Term [+-] Exp | Term
Term => Factor [*/] Term | Factor
Factor => Funcall | Var | Num | [(] Exp[)]
Funcall => Var [(] Exp[)]
Exps => Exp [,] Exps | Exp
Var => [a-zA-Z_]\w*
Num => [-+]?[.][0-9]*)
""")

JSON = grammar("""
object => { } | { members }
members => pair, members | pair
pair => string: value
array => [[][]] | [[] elements []]
elements => value, elements | value
value => string | number | object | array | true | false | null
string => "[^"]*"
number => int frac exp | int frac | int exp | int
int => ->[1-9][0-9]*
frac => [.][0-9]+
exp => [eE][-+]?[0-9]+
""", whitespace='\s*')

def inverse(f, delta=1/128.):
def f_1(y):
x = 0
while f(x) < y: x += delta return x if (f(x)-y < y-f(x-delta)) else x-delta return f_1 def square(x): return x * x print sqrt(100) print sqrt(99) print sqrt(100000000) [/python]

def match1(p, text):
	if not text: return False
	return p == '.' or p == text[0]

def match_star(p, pattern, text):
	return (match(pattern, text) or
			(match(p, text) and
				match_star(p, pattern, text[1:])))

print test()

api

def lit(string):  return ('lit', string)
def seq(x, y):    return ('seq', x, y)
def alt(x, y):    return ('alt', x, y)
def star(x):      return ('star', x)
def plus(x):      return seq(x, star(x))
def opt(x):       return alt(lit(''), x) #opt(x) means that x is optional
def oneof(chars): return ('oneof', tuple(chars))
dot = ('dot',)
eol = ('eol',)

def search(pattern, text):
	for i in range(len(text)):
		m = match(pattern, text[i:])
		if :
			return m

def match(pattern, text):
	remainders = matchset(pattern, text)
	if remainders:
		shortest = min(remainders, key=len)
		return

def components(pattern):
	x = pattern[1] if len(pattern) > 1 else None
	y = pattern[2] if len(pattern) > 2 else None
	return pattern[0], x, y

def matchset(pattern, text):
	elif 'seq' == op:
		return set(t2 for t1 in matchset(x, text) for t2 in matchset(y, t1))

def seq(x, y) return lambda text: set().union(*map(y, x(text)))

def alt(x, y) return lambda text: x(text) | y(ext)

def genseq(x, y, Ns):
	Nss = range(max(Ns)+1)
	return set(m1 + m2
		for m1 in x(Nss) for m2 in y(Nss)
		if len(m1 + m2) in Ns)

def compile_word(word):
	if word.isupper():
		terms = [('%s*%s' % (10**i, d))
			for (i, d) in enumerate(word[::-1])]
		return '(' + '+'.join(terms) + ')'
	else:
		return word

Regular Expression
->find substring string

ex. s = ‘some long thing with words’
s.find(‘word’)

‘baa*!’

* a*
? a?
. a.

def search(pattern, text):
	if pattern.startswitch('^'):
		return match(pattern[l:], text)
	else:
		return match('.*' + pattern, text)

def match(pattern, text):
	if pattern == '':
		return True
	elif pattern == '$':
		return (text == '')
	elif len(pattern) > 1 and pattern[1] in '*?':

	else:
		return (match1(pattern[0], text) and
		match(pattern[1:], text[1:]))

import itertools

houses = [1, 2, 3, 4, 5]
orderings = list(itertools.permutation(houses))

for (red, green, ivory, yellow, blue) in orderings:
	for (Englishman, Spaniard, Ukranian, Japanese, Norwegian) in orderings:
		for (dog, snails, fox, horse, ZEBRA) in orderings:
			for (coffee, tea, milk, oj, WATER) in orderings:
				for (oldGold, kools, Chesterfields, LuckyStrike, Parliaments) in orderings:

def zebra_puzzle():
	houses = first, _, middle, _, _ = [1, 2, 3, 4, 5]
	orderings = list(itertools.permutations(houses))
	return next((WATER, ZEBRA)

import time

def t():
	t0 = time.clock()
	zebra_puzzle()
	t1 = time.clock()
	return t1-t0

print t()

def timecall(fn, *args):
	t0 = time.clock()
	result = fn(*args)
	t1 = time.clock()
	return t1-t0

def timecall(fn, *args):
	t0 = time.clock()
	result = fn(*args)
	t1 = time.clock()
	return t1-t0

def timedcalls(n, fn, *args):
	times = [timedcall(fn, *args)[0] for _ in range(n)]
	return min(times), average(times), max(times)

def average(numbers):
	return sum(numbers) / float(len(numbers))

def instrument_fn(fn, *args):
	c.starts, c.items = 0, 0
	result = fn(*args)
	print '%s got %s with %5d iters over %7d items' % (
		fn.__name__, result, c.starts, c.items)

def ints(start, end):
i = start
while i <= end yield i i = i + 1 [/python] [python] def all_ints(): "Generate integers in the order 0, +1, -1, +2, -2, +3, -3,..." yield 0 for i in ints(1): yield +i yield -i [/python] [python] import string, re def valid(f): try: return not re.search(r'\b0[0-9]', f) and eval(f) is True except ArithmeticError: return False [/python] [python] import string, re def solve(formula): def valid(f): try: return not re.search(r'\b0[0-9]', f) and eval(f) is True except ArithmeticError: return False [/python]

import random

mydeck = [r+s for r in '23456789TJQKA' for s in 'SHDC']

def deal(numhands, n=5, deck=mydeck)
	random.shuffle(deck)
	return [deck[n*i:n*(i+1)] for i in range(numhands)]

def hand_percentages(n=700*1000):
	"sample n random hands and print a table of percentages for each type of hand."
	counts = [0] * 9
	for i in range(n/10):
		for hand in deal(10):
			ranking = hand_rank(hand)[0]
			counts[ranking] += 1
	for i in reversed(range(9)):
		print "%14s: %6.3f %%" % (hand_names[i], 100.*counts[i]/n)

def shuffle1(deck):
	N = len(deck)
	swapped = [False] * N
	while not all(swapped)
		i, j = random.randrange(N), random.randrange(N)
		swapped[i] = swapped[j] = True
		swap(deck, i, j)

def swap(deck, i, j):
	print 'swap', i, j
	deck[i], deck[j] = deck[j], deck[i]

utas = ['Peter', 'Andy', 'Sarah', 'Gundega', 'Job', 'Sean']
uppercasetas = [name.upper() for name in utas]
print uppercasetas

def ss(nums):
	total = 0
	for i in range(len(nums)):
		total = (total + num[i]**2)
	return total

def ss(nums):
	return sum(x**2 for x in nums)

poker problem set
[‘js’,’jd’,’2s’,’2c’,’7h’]
[(11,’s’),(11,’d’),(2,’s’),(2,’c’),(7,’h’)]

key abs mean absolute value, so -5 would be max nums

def poker(hands):
	"Return the best hand: poker([hand,...]) => hand"
	return max

print max([3, 4, 5, 0]), max([s, 4, -5, 0], key=abs)

highest rank

def poker(hands):
	"Return the best hand: poker([hand,...]) => hand"
	return max(hands, key=hand_rank)

def hand_rank(hand)
	return ???

print max([3, 4, 5, 0]), max([s, 4, -5, 0], key=abs)

Testing

def poker(hands):
    "Return the best hand: poker([hand,...]) => hand"
    return max(hands, key=hand_rank)

def test():
    "Test cases for the functions in poker program"
    sf = "6C 7C 8C 9C TC".split() 
    fk = "9D 9H 9S 9C 7D".split() 
    fh = "TD TC TH 7C 7D".split()
    assert poker([sf, fk, fh]) == sf
    assert poker([fk, fh]) == fk
    assert poker([fh, fh]) == fh
    assert poker([sf]) == sf
    assert poker([sf] + 99*[fh]) == sf
    return 'tests pass'

def hand_rank(hand):
	"Return a value indicating the ranking of a hand"
    ranks = card_ranks(hand)
    if straight(ranks) and flush(hand):            # straight flush
        return (8, max(ranks))
    elif kind(4, ranks):                           # 4 of a kind
        return (7, kind(4, ranks), kind(1, ranks))
    elif kind(3, ranks) and kind(2, ranks):        # full house
        return (6, kind(3, ranks), kind(2, ranks))
    elif flush(hand):                              # flush
        return (5, ranks)
    elif straight(ranks):                          # straight
        return (4, max(ranks))
    elif kind(3, ranks):                           # 3 of a kind
        return (3, kind(3, ranks), ranks)
    elif two_pair(ranks):                          # 2 pair
        return (2, two_pair(ranks), ranks)
    elif kind(2, ranks):                           # kind
        return (1, kind(2, ranks), ranks)
    else:                                          # high card
        return (0, ranks)

def poker(hands):
    "Return the best hand: poker([hand,...]) => hand"
    return allmax(hands, key=hand_rank)

def allmax(iterable, key=None):
	"Return a list of all items equal to the max of the iterable."
	result, maxval = [], None
	key = key or (lambda x: x)
	for x in iterable:
		xval = key(x)
		if not result or xval > maxval:
			result, maxval = [x], xval
		elif xval == maxval:
			result.append(x)
	return result

def hand_rank(hand):
	"Return a value indicating the ranking of a hand"
    ranks = card_ranks(hand)
    if straight(ranks) and flush(hand):            # straight flush
        return (8, max(ranks))
    elif kind(4, ranks):                           # 4 of a kind
        return (7, kind(4, ranks), kind(1, ranks))
    elif kind(3, ranks) and kind(2, ranks):        # full house
        return (6, kind(3, ranks), kind(2, ranks))
    elif flush(hand):                              # flush
        return (5, ranks)
    elif straight(ranks):                          # straight
        return (4, max(ranks))
    elif kind(3, ranks):                           # 3 of a kind
        return (3, kind(3, ranks), ranks)
    elif two_pair(ranks):                          # 2 pair
        return (2, two_pair(ranks), ranks)
    elif kind(2, ranks):                           # kind
        return (1, kind(2, ranks), ranks)
    else:                                          # high card
        return (0, ranks)

def card_ranks(cards):
    "Return a list of the ranks, sorted with higher first."
    ranks = ['--23456789TJQKA'.index(r) for r,s in cards]
    ranks.sort(reverse=True)
    return [5, 4, 3, 2, 1] if (ranks == [14, 5, 4, 3, 2])

def straight(ranks):
	"Return True if the ordered ranks form a 5-card straight."
	return (max(ranks)-min(ranks) == 4) and len(set(ranks)) == 5

def flush(hand):
	"Return True if all the cards have the same suit."
	suits = [s for r, s in hand]
	return len(set(suits)) == 1

def kind(n, ranks):
	"""Return the first rank that this hand has exactly n of.
	Return None if there is no n-of-a-kind in the hand."""
	for r in ranks:
		if ranks.count(r) == n: return r
	return None

def two_pair(ranks):
	"""If there are two pair, return the two ranks as a
	tuple: (highest, lowest); otherwise return None."""
	pair = kind(2, ranks)
	lowpair = kind(2, list(reversed(ranks)))
	if pair and lowpair != pair:
		return (pair, lowpair)
	else:
		return None

def test():
    "Test cases for the functions in poker program"
    sf = "6C 7C 8C 9C TC".split() # Straight Flush
    fk = "9D 9H 9S 9C 7D".split() # Four of a Kind
    fh = "TD TC TH 7C 7D".split() # Full House
    tp = "5S 5D 9H 9C 6S".split() # two pair
    s1 = "AS 2S 3S 4S 5C".split() # A-5 straight
    s2 = "2C 3C 4C 5S 6S".split() # 2-6 straight
    ah = "AS 2S 3S 4S 6C".split() # A high
    sh = "2S 3S 4S 6C 7D".split() # 7 high
    assert poker([s1, s2, ah, sh]) == s2
    fkranks = card_ranks(fk)
    tpranks = card_ranks(tp)
    assert kind(4, fkranks) == 9
    assert kind(3, fkranks) == None
    assert kind(2, fkranks) == None
    assert kind(1, fkranks) == 7
    assert two_pair(fkranks) == None
    assert two_pair(tpranks) == (9, 5)
    assert straight([9, 8, 7, 6, 5]) == True
    assert straight([9, 8, 8, 6, 5]) == False
    assert flush(sf) == True
    assert flush(fk) == False
    assert card_ranks(sf) == [10, 9, 8, 7, 6]
    assert card_ranks(fk) == [9, 9, 9, 9, 7]
    assert card_ranks(fh) == [10, 10, 10, 7, 7]
    assert poker([sf, fk, fh]) == sf
    assert poker([fk, fh]) == fk
    assert poker([fh, fh]) == fh
    assert poker([sf]) == sf
    assert poker([sf] + 99*[fh]) == sf
    assert hand_rank(sf) == (8, 10)
    assert hand_rank(fk) == (7, 9, 7)
    assert hand_rank(fh) == (6, 10, 7)
    return 'tests pass'