TOC
1. 背景形容
最近在写一个后端我的项目，次要的操作就是依据用户的前端数据，在后端关上我的项目中的代码文件，批改对应地位的参数，因为在目前的后端我的项目中常常应用这个操作，所以简略总结一下。
1. 文件门路：./test.c2. 文件内容……case EPA: chan_desc->nb_taps = 7; chan_desc->Td = .410; chan_desc->channel_length = (int) (2*chan_desc->sampling_rate*chan_desc->Td + 1 + 2/(M_PI*M_PI)*log(4*M_PI*chan_desc->sampling_rate*chan_desc->Td)); sum_amps = 0; chan_desc->amps = (double *) malloc(chan_desc->nb_taps*sizeof(double)); chan_desc->free_flags=chan_desc->free_flags|CHANMODEL_FREE_AMPS ; for (i = 0; i<chan_desc->nb_taps; i++) { chan_desc->amps[i] = pow(10,.1*epa_amps_dB[i]); sum_amps += chan_desc->amps[i]; } for (i = 0; i<chan_desc->nb_taps; i++) chan_desc->amps[i] /= sum_amps; chan_desc->delays = epa_delays; chan_desc->ricean_factor = 1;//待批改地位 chan_desc->aoa = 0;//待批改地位 chan_desc->random_aoa = 0;//待批改地位 chan_desc->ch = (struct complexd **) malloc(nb_tx*nb_rx*sizeof(struct complexd *)); chan_desc->chF = (struct complexd **) malloc(nb_tx*nb_rx*sizeof(struct complexd *)); chan_desc->a = (struct complexd **) malloc(chan_desc->nb_taps*sizeof(struct complexd *));……2. 单行批改-操作步骤
读取文件
应用python中的open()函数进行文件读取，将数据存储在缓冲区。#1. 读取文件path='./test.c'with open(path, 'r') as file: file_content = file.read()查找文件替换地位
以查找chan_desc->ricean_factor = 1;//待批改地位为例，查找这句话的终点和起点。## 注：此步骤须要import re#2. 查找文件替换地位start_index=file_content.find('chan_desc->ricean_factor = ')#终点end_index=file_content.find('chan_desc->aoa = ',start_index)#起点if end_index==-1 or start_index==-1: print('未找到待批改地位')#此时失去的两个指针，别离指向了待批改地位的终点和起点，如下图所示：设置替换文件内容
假如目前只批改这一行的参数，#3. 设置替换文件内容ricean_factor=3#假如这是要批改的参数信息updata_content=file_content[:start_index]#获取这行代码之前的内容update_content+='chan_desc->ricean_factor = '+str(ricean_factor)+';//待批改地位'#批改这行代码update_content+=file_content[end_index:]#获取这行代码之后的内容#此时失去的update_content就是批改后的残缺文件内容，只批改了ricean_factor这一行的值写入文件
同样应用python中的open函数。#4. 写入文件if update_content!="":#如果批改内容不为空 with open(path, 'w') as file:#w示意笼罩写入，之前的内容都会被笼罩 file.write(update_content)总代码
整体的代码如下所示：import re#1. 读取文件path='./test.c'with open(path, 'r') as file: file_content = file.read()#2. 查找文件替换地位start_index=file_content.find('chan_desc->ricean_factor = ')#终点end_index=file_content.find('chan_desc->aoa = ',start_index)#起点if end_index==-1 or start_index==-1: print('未找到待批改地位')#3. 设置替换文件内容ricean_factor=3#假如这是要批改的参数信息updata_content=file_content[:start_index]#获取这行代码之前的内容update_content+='chan_desc->ricean_factor = '+str(ricean_factor)+';//待批改地位'#批改这行代码update_content+=file_content[end_index:]#获取这行代码之后的内容#4. 写入文件if update_content!="":#如果批改内容不为空 with open(path, 'w') as file:#w示意笼罩写入，之前的内容都会被笼罩 file.write(update_content)3. 多行批改-操作步骤
- 多行批改思路
多行批改有两种批改思路，如果批改局部比拟集中，则可间接替换一整块的字符串内容，如果批改局部较为扩散，则须要独自查找批改地位，而后再别离进行替换。 多行批改-整块替换
try: with open(file_path, "r") as file: file_content = file.read()except Exception as e: return str(e)# 设置改写内容updated_content = "" # 查找批改start_index_1 = file_content.find("start_sentence")#要确保查找元素的唯一性end_index_1 = file_content.find("end_sentence",start_index_1,) if start_index_1 == -1 or end_index_1 == -1: print("未找到待批改地位") return -1 # updated_content = file_content[:start_index_1]#获取这行代码之前的内容 updated_content += "start_sentence和end_sentence之间的sentence_1;\n" updated_content += "start_sentence和end_sentence之间的sentence_2;\n" updated_content +=file_content[end_index_1:] ##此时updated_content就是批改后的残缺文件内容 if updated_content != "": with open(file_path, "w") as file: file.write(updated_content)else: print("批改失败") return -1多行批改-部分替换
try: with open(file_path, "r") as file: file_content = file.read()except Exception as e: return str(e)# 设置改写内容updated_content = "" # 查找批改start_index_1 = file_content.find("start_sentence_1")#要确保查找元素的唯一性end_index_1 = file_content.find("end_sentence_1",start_index_1,) start_index_2 = file_content.find("start_sentence_2",end_index_1)end_index_2 = file_content.find("end_sentence_2",start_index_2,)start_index_3 = file_content.find("start_sentence_3",end_index_2)end_index_3 = file_content.find("end_sentence_3",start_index_3,)start_index_4 = file_content.find("start_sentence_4",end_index_3)end_index_4 = file_content.find("end_sentence_4",start_index_4,)if ( start_index_1 == -1 or end_index_1 == -1 or start_index_2 == -1 or end_index_2 == -1 or start_index_3 == -1 or end_index_3 == -1 or start_index_4 == -1 or end_index_4 == -1 ): print("未找到待批改地位") return -1 # updated_content = file_content[:start_index_1]#获取这行代码之前的内容 updated_content += "start_sentence_1和end_sentence_1之间的内容" updated_content +=file_content[end_index_1:start_index_2] updated_content += "start_sentence_2和end_sentence_2之间的内容" updated_content +=file_content[end_index_2:start_index_3] updated_content += "start_sentence_3和end_sentence_3之间的内容" updated_content +=file_content[end_index_3:start_index_4] updated_content += "start_sentence_4和end_sentence_4之间的内容" updated_content += file_content[end_index_4:] ##此时updated_content就是批改后的残缺文件内容 if updated_content != "": with open(file_path, "w") as file: file.write(updated_content)else: print("批改失败") return -1