C++跳过csv文件的第一行
问题描述:
我得到我的程序从.csv文件读取并输出数据,但我不希望它输出第一行。我试过使用getline(data, line);
和stream.ignore (std::numeric_limits<std::streamsize>::max(), '\n');
。尽管它没有跳过第一行,但最后两行打印两次并混合起来。C++跳过csv文件的第一行
string ID;
string sentenceIn;
string servedIn;
int sentence;
int served;
string lastName;
string firstName;
vector<string> idNum;
vector<string> sentenceLen;
vector<string> servedTime;
vector<string> lastNameIn;
vector<string> firstNameIn;
ifstream data("prisoner_data.csv");
if (data.is_open())
{
cout << "File opened successfully." << endl << endl;
while (data.good()) // !someStream.eof()
{
getline(data, ID, ',');
cout << ID << " ";
idNum.push_back(ID);
getline(data, sentenceIn, ',');
cout << sentenceIn << " ";
sentenceLen.push_back(sentenceIn);
istringstream(sentenceIn) >> sentence;
getline(data, servedIn, ',');
cout << servedIn << " ";
servedTime.push_back(servedIn);
istringstream(servedIn) >> served;
getline(data, lastName, ',');
lastNameIn.push_back(lastName);
cout << lastName << " ";
getline(data, firstName, ',');
firstNameIn.push_back(firstName);
cout << firstName << " ";
}
}
我能做些什么,以跳过不搞乱了最后的第一行?
答
while (data.good())
很腥。你最终会“吃”多一行。见例如Why is iostream::eof inside a loop condition considered wrong?了解更多详情。通常你直接在while
测试的getline
的结果,就像
while(getline(data, line)){...}
一个可能的解决方案是用while(getline(data, line)){...}
到逐行读取文件中的行,然后用stringstream(line)
和每行,再次与getline
解析它,现在分开,
。要跳过第一行,请先执行getline(data, line);
,然后再执行while(getdata(data, line)){ /* process line */}
。一个简单的例子如下:
#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
#include <cstdlib>
int main()
{
std::ifstream data("prisoner_data.csv");
if (!data.is_open())
{
std::exit(EXIT_FAILURE);
}
std::string str;
std::getline(data, str); // skip the first line
while (std::getline(data, str))
{
std::istringstream iss(str);
std::string token;
while (std::getline(iss, token, ','))
{
// process each token
std::cout << token << " ";
}
std::cout << std::endl;
}
}
谢谢你,这完美的作品。但是,我需要'句子'和'服务'是整数。我如何使用这种方式转换它们? – Andre
@Andre您可以使用['std :: stoi'](http://en.cppreference.com/w/cpp/string/basic_string/stol)将字符串转换为整数。 – vsoftco