python list常用操作封装，pythonlist封装,如下是一系列list相关

python list常用操作封装，pythonlist封装,如下是一系列list相关

如下是一系列list相关的函数封装：

#========================================================================def sumList(L):    return reduce(lambda x,y:x+y, L)#========================================================================def avgList(L):    return reduce(lambda x,y:x+y, L) /(len(L)*1.0)#========================================================================def normList(L, normalizeTo=1):    '''normalize values of a list to make its max = normalizeTo'''    vMax = max(L)    return [ x/(vMax*1.0)*normalizeTo for x in L]#========================================================================def normListSumTo(L, sumTo=1):    '''normalize values of a list to make it sum = sumTo'''    sum = reduce(lambda x,y:x+y, L)    return [ x/(sum*1.0)*sumTo for x in L]#========================================================================def accumList(L, normalizeTo=None):    ''' L= [1, 2, 3,  4,  5]:        accumList(L)=> [1, 3, 6, 10, 15]         L= [0.25, 0.25, 0.25, 0.25]: accumList(L)=> [0.25, 0.50, 0.75, 1.00]        normalizeTo: set the last number of the returned list to this value    '''    if normalizeTo: LL = normListSumTo(L, sumTo=normalizeTo)    else: LL = L[:]    r = range(1, len(LL))    newList=[LL[0]]    for i in r:        newList.append( newList[-1]+ LL[i] )    return newList#========================================================================def findIndex(sortedList, x, indexBuffer=0):  ''' Given a sortedList and value x, return the index i where      sortedList[i-1] <= x < sortedList[i]      Which means,        sortedList.insert( findIndex(sortedList, x), x )      will give a sorted list    '''  if len(sortedList)==2:    if x==sortedList[-1]:   return indexBuffer+2    elif x>=sortedList[0]:  return indexBuffer+1  else:    L = len(sortedList)      firstHalf  = sortedList[:L/2+1]    secondHalf = sortedList[(L/2):]    if secondHalf[-1]<=x:      return indexBuffer + len(sortedList)    elif x< firstHalf[0]:      return indexBuffer    else:      if firstHalf[-1] < x:        return findIndex(secondHalf, x, indexBuffer=L/2+indexBuffer)      else:        return findIndex(firstHalf,x, indexBuffer=indexBuffer)#========================================================================def randomPickList(L):    ''' given a list L, with all values are numbers,        randomly pick an item and return it's index according        to the percentage of all values'''    return findIndex(accumList(L,1), random.random())#========================================================================def deepList(LString):    '''    Given string representation of a nested list tree,    return a list containing all the deepest list contents.    For example:    '[[1,[2, 2a]],[[3,3b],4]]'    ==> ['2, 2a', '3,3b']    '[[[1,[2, 2a]],[[3,3b],4]],6]'    ==> ['2, 2a', '3,3b']    '[[[[a1,a2],out],o1],[o2,o3]]'    ==> ['a1,a2', 'o2,o3']    '[[[[[a1,a2], out], [o1,o2]],[o3,o4]],[o5,o6]]'    ==> ['a1,a2', 'o1,o2', 'o3,o4', 'o5,o6']    The code: [x.split(']') for x in code.split('[')]    returns something like:    [[''], [''], [''], [''], [''], ['a1,a2', ', out', ', '],    ['o1,o2', '', ','], ['o3,o4', '', ','], ['o5,o6', '', '']]    '''    result= [x[0] for x in \            [x.split(']') for x in LString.split('[')] \            if len(x)>1]    if result==['']: result =[]    return result#========================================================================def getListStartsWith(aList, startsWith, isStrip=1):    ''' for a list:   L= ['abcdef', 'kkddff', 'xyz', '0wer'...],        getListStartWith(L, 'kk') will return:           ['kkddff', 'xyz', '0wer'...],        getListStartWith(L, 'xy') will return:           ['xyz', '0wer'...],        if isStrip: any item '  xyz' will be considered 'xyz'        else:       the spaces in '  xyz' count.    '''    tmp = aList[:]    if isStrip: tmp = [x.strip() for x in tmp]    startLineIndex = 0    for i in range(len(tmp)):        if tmp[i].startswith(startsWith):            startLineIndex = i    return aList[startLineIndex:]#========================================================================def rezip(aList):    ''' d = [[1, 5, 8, 3], [2, 2, 3, 9], [3, 2, 4, 6]]        rezip(d):        [(1, 2, 3), (5, 2, 2), (8, 3, 4), (3, 9, 6)]    If a =[1, 5, 8], b=[2, 2, 3], c=[3, 2, 4]    then it's eazy to: zip(a,b,c) = [(1, 2, 3), (5, 2, 2), (8, 3, 4)]    But it's hard for d = [[1, 5, 8], [2, 2, 3], [3, 2, 4]]        '''    tmp = [ [] for x in range(len(aList[0])) ]    for i in range(len(aList[0])):        for j in range(len(aList)):            tmp[i].append(aList[j][i])    return tmp#========================================================================def sumInList(complexList):  ''' Given a complexList [ [a1,b1,c1], [a2,b2,c2], [a3,b3,c3] ],      return a list [ a, b, c] where a = a1+a2+a3, etc.'''  d = rezip(complexList)  return [ reduce(lambda x,y:x+y, z) for z in d ]#========================================================================def avgInList(complexList):  ''' Given a complexList [ [a1,b1,c1], [a2,b2,c2], [a3,b3,c3] ],      return a list [ a, b, c] where a = avg of a1, a2, a3, etc.'''  d = rezip(complexList)  return [ reduce(lambda x,y:x+y, z)/(len(z)*1.0) for z in d ]