ph87

def permutations(iterable, r=None):
    # permutations('ABCD', 2) --> AB AC AD BA BC BD CA CB CD DA DB DC
    # permutations(range(3)) --> 012 021 102 120 201 210
    pool = tuple(iterable)
    n = len(pool)
    r = n if r is None else r
    if r > n:
        return
    indices = range(n)
    cycles = range(n, n-r, -1)

ph87

#!/usr/bin/env python
# encoding: utf-8

import time


def multi_acquire_worker(mutex):
    ''' 同一线程多次请求同一资源，直接造成死锁

    为了解决在同一线程中多次请求同一资源，使用可重入锁 threading.RLock

ph87

def grep(pattern_str):
    ''' Using yield receive data inside generator

    :param pattern_str: rex string

    Demo::
        >>> finder = grep('target \d+')
        >>> next(finder)
        >>> print(finder.send('target 1234'))
        target 1234

ph87

object exercise {
    def mapReduce(
        func: Int=>Int, combine: (Int, Int) => Int, zero: Int
        )(a: Int, b: Int):  Int = {
            if (a > b) zero
            else combine(
                func(a),
                mapReduce(func, combine, zero)(a + 1, b)
            )
    }

ph87

package recfun

object Main {
  def main(args: Array[String]) {
    println("Pascal's Triangle")
    for (row <- 0 to 10) {
      for (col <- 0 to row)
        print(pascal(col, row) + " ")
      println()
    }

ph87

autocmd BufWritePost *.py exec ":call PyFlakeTest()"
function! PyFlakeTest()
    silent exec "!flake8 % > /dev/null"
    if v:shell_error 
        echohl ErrorMsg
        echomsg  "不好！有毛病！"
        exec "!flake8 %"
        echohl None
    endif
endfunc

ph87

import sys
data = {}
for i in xrange(0, 1000000):
  lst.append(i)
  size = sys.getsizeof(list)
  if data.get(size):
    pass
  else:
    data[size] = i
rev_data = {i[1]: i[0] for i in data.items()}

ph87

from unittest import (
        main,
        TestCase,
        )
from random import Random


def merge(lst):
    if len(lst) <= 1:
        return lst

ph87

import re
import logging
from logging import handlers as logging_handlers
import email
from email.parser import Parser
from email.header import decode_header
from email.utils import parseaddr
from StringIO import StringIO

logger = logging.getLogger(__name__)

ph87

from md5 import md5

PREFIX = 'v2ex'

LETTERS = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890'

TARGET = '3bed22f7f496e84b035a996522baa7594c27c7e5718a78bfddf9012904b70eb755d67f90c8de149ead7ee674b024f38c216642030c2d54cb1dd657dd66342c99c239f3c31fd399fc052a9b7861f2073d2b9f47811dd77fd544d570c34bf5f349d110389979571714694a5054238465ca38ba26c25fb1a32b4d0a3b93666b09b3' 

prefix_md5 = md5(PREFIX).hexdigest()