一个小项目中的Python中的性能优化细节——（下）其他的小细节，减少调用、if判断的顺序_python 判断代码执行效率

<span style="white-space:pre">			</span>D_Ascii = { } #this will save time about 0.1s
			D_Freq = { } #avoid create&destroy a pointer in for loop 
			for index_Word in range(len(lines_Word)-2):
				index_AsciiHash = ord(lines_Word[index_Word][0])  #this one costs 1.4 s
				str_Key = lines_Word[index_Word][0:-1] + str_const_GLUE + lines_Word[index_Word+1][0:-1] #costs 1.4s
				#str_Key = f_glue_word(lines_Word[index_Word][:-1],lines_Word[index_Word+1][:-1]) #costs  2.5s
				str_NextWord = lines_Word[index_Word+2][:-1] #costs 0.5s
				D_Ascii = self.list_AsciiHash[index_AsciiHash] #datatype -- dict_AciiHash_Dict
				D_Freq = self.list_KeyFreq_Dict_asciihash[index_AsciiHash] #costs 0.5s

				if str_Key not in D_Ascii: #put "not in" in front of "in",save 0.4s, because in will cause extra judge
					D_Ascii[str_Key] = { str_NextWord : 1 }#costs 1.4s
					D_Freq[str_Key] = 1#555
					
				else:
					if str_NextWord in D_Ascii[str_Key]:#666
						D_Ascii[str_Key][str_NextWord]+=1#666
					else:#666
						D_Ascii[str_Key][str_NextWord]=1#666
					D_Freq[str_Key] += 1#555