00001 '''This module collects some frequently used helper functions
00002 '''
00003 import time,ast,re,json,coral,array
00004 def pairwise(lst):
00005 """
00006 yield item i and item i+1 in lst. e.g.
00007 (lst[0], lst[1]), (lst[1], lst[2]), ..., (lst[-1], None)
00008
00009 from http://code.activestate.com/recipes/409825-look-ahead-one-item-during-iteration
00010 """
00011 if not len(lst): return
00012
00013 for i in range(len(lst)-1):
00014 yield lst[i], lst[i+1]
00015 yield lst[-1], None
00016 def findInList(mylist,element):
00017 """
00018 check if an element is in the list
00019 """
00020 pos=-1
00021 try:
00022 pos=mylist.index(element)
00023 except ValueError:
00024 pos=-1
00025 return pos!=-1
00026 def is_intstr(s):
00027 """test if a string can be converted to a int
00028 """
00029 try:
00030 int(s)
00031 return True
00032 except ValueError:
00033 return False
00034 def is_floatstr(s):
00035 """
00036 test if a string can be converted to a float
00037 """
00038 try:
00039 float(s)
00040 return True
00041 except ValueError:
00042 return False
00043 def count_dups(l):
00044 """
00045 report the number of duplicates in a python list
00046 """
00047 from collections import defaultdict
00048 tally=defaultdict(int)
00049 for x in l:
00050 tally[x]+=1
00051 return tally.items()
00052 def transposed(lists, defaultval=None):
00053 """
00054 transposing list of lists
00055 from http://code.activestate.com/recipes/410687-transposing-a-list-of-lists-with-different-lengths/
00056 """
00057 if not lists: return []
00058 return map(lambda *row: [elem or defaultval for elem in row], *lists)
00059 def pack(high,low):
00060 """pack high,low 32bit unsigned int to one unsigned 64bit long long
00061 Note:the print value of result number may appear signed, if the sign bit is used.
00062 """
00063 h=high<<32
00064 return (h|low)
00065 def packToString(high,low):
00066 """pack high,low 32bit unsigned int to one unsigned 64bit long long in string format
00067 Note:the print value of result number may appear signed, if the sign bit is used.
00068 """
00069 fmt="%u"
00070 return fmt%pack(high,low)
00071 def unpack(i):
00072 """unpack 64bit unsigned long long into 2 32bit unsigned int, return tuple (high,low)
00073 """
00074 high=i>>32
00075 low=i&0xFFFFFFFF
00076 return(high,low)
00077 def unpackFromString(i):
00078 """unpack 64bit unsigned long long in string format into 2 32bit unsigned int, return tuple(high,low)
00079 """
00080 return unpack(int(i))
00081 def timeStamptoDate(i):
00082 """convert 64bit timestamp to local date in string format
00083 """
00084 return time.ctime(unpack(i)[0])
00085 def timeStamptoUTC(i):
00086 """convert 64bit timestamp to Universal Time in string format
00087 """
00088 t=unpack(i)[0]
00089 return time.strftime("%a, %d %b %Y %H:%M:%S +0000",time.gmtime(t))
00090 def unpackLumiid(i):
00091 """unpack 64bit lumiid to dictionary {'run','lumisection'}
00092 """
00093 j=unpack(i)
00094 return {'run':j[0],'lumisection':j[1]}
00095 def inclusiveRange(start,stop,step):
00096 """return range including the stop value
00097 """
00098 v=start
00099 while v<stop:
00100 yield v
00101 v+=step
00102 if v>=stop:
00103 yield stop
00104
00105 def tolegalJSON(inputstring):
00106 '''
00107 convert json like string to legal json string
00108 add double quote around json keys if they are not there, change single quote to double quote around keys
00109 '''
00110 strresult=inputstring.strip()
00111 strresult=re.sub("\s+","",strresult)
00112 try:
00113 mydict=ast.literal_eval(strresult)
00114 except SyntaxError:
00115 print 'error in converting string to dict'
00116 raise
00117 result={}
00118 for k,v in mydict.items():
00119 if not isinstance(k,str):
00120 result[str(k)]=v
00121 else:
00122 result[k]=v
00123 return re.sub("'",'"',str(result))
00124
00125 def packArraytoBlob(iarray):
00126 '''
00127 Inputs:
00128 inputarray: a python array
00129 '''
00130 result=coral.Blob()
00131 result.write(iarray.tostring())
00132 return result
00133
00134 def unpackBlobtoArray(iblob,itemtypecode):
00135 '''
00136 Inputs:
00137 iblob: coral.Blob
00138 itemtypecode: python array type code
00139 '''
00140 if itemtypecode not in ['c','b','B','u','h','H','i','I','l','L','f','d']:
00141 raise RuntimeError('unsupported typecode '+itemtypecode)
00142 result=array.array(itemtypecode)
00143 result.fromstring(iblob.readline())
00144 return result
00145
00146 def packListstrtoCLOB(iListstr,separator=','):
00147 '''
00148 pack list of string of comma separated large string CLOB
00149 '''
00150 return separator.join(iListstr)
00151
00152 def unpackCLOBtoListstr(iStr,separator=','):
00153 '''
00154 unpack a large string to list of string
00155 '''
00156 return [i.strip() for i in iStr.strip().split(separator)]
00157
00158 if __name__=='__main__':
00159 a=[1,2,3,4,5]
00160 for i,j in pairwise(a):
00161 if j :
00162 print i,j
00163 lst = ['I1','I2','I1','I3','I4','I4','I7','I7','I7','I7','I7']
00164 print count_dups(lst)
00165 seqbag=[[1,2,3],[1,3,3],[1,4,6],[4,5,6,7],[8,9]]
00166 print 'before ',seqbag
00167 print 'after ',transposed(seqbag,None)
00168 print [i for i in inclusiveRange(1,3,1)]
00169
00170 result=tolegalJSON('{1:[],2:[[1,3],[4,5]]}')
00171 print result
00172 pp=json.loads(result)
00173 print pp["2"]
00174 result=tolegalJSON("{'1':[],'2':[[1,3],[4,5]]}")
00175 print result
00176 pp=json.loads(result)
00177 print pp["2"]
00178 result=tolegalJSON('{"1":[],"2":[[1,3],[4,5]]}')
00179 print result
00180 pp=json.loads(result)
00181 print pp["2"]
00182
00183 a=array.array('f')
00184 a.append(1.3)
00185 a.append(1.4)
00186 a.append(2.3)
00187 a.append(6.3)
00188 myblob=packArraytoBlob(a)
00189 print myblob.size()
00190 print unpackBlobtoArray(myblob,'f')
00191 b=array.array('f')
00192 myblob=packArraytoBlob(b)
00193 print myblob.size()
00194 a=['aa_f', 'bb', 'dfc']
00195 print packListstrtoCLOB(a)