c - 将 CSV 文件存储到 C 中的 Float Matrix

Question

代码没有将行的最后一个逗号之后的值存储到矩阵中...

full list.csv 就像:

123456,57,45,,67,,56,,63,,,72,67,,,,34,56,,,,,56,,,,,,,,,,,,,,45,,,,,1523521
123457,57,45,,67,,56,,634,,,72,67,,,,34,56,,,,,56,,,,,,,,,,,,,,45,,,1234,,
123458,57,45,,67,,56,,63,,,724,67,,,,34,56,,,,,56,,,,,,,,,,,,,,45,,,,1234,
123459,57,45,,67,,56,,63,,,72,647,,,,34,56,,,,,56,,,,,,,,,,,,,,45,,,,,1234
123450,57,45,,67,,56,,63,,,72,67,,,,344,56,,,,,56,,,,,,,,,,,,,,45,,,,,124
123451,57,45,,67,,56,,63,,,72,67,,,,34,564,,,,,56,,,,,,,,,,,,,,45,,,,,
123452,57,45,,67,,56,,63,,,72,67,,,,34,56,,,,,564,,,,,,,,,,,,,,45,,,,,124
123453,57,45,,67,,56,,63,,,72,67,,,,34,56,,,,,56,,,,,,,,,,,,,,454,,,,,
123454,57,45,,67,,56,,63,,,72,67,,,,34,56,,,,,56,,,,,,,,,,,,,,45,,,,,124
123455,574,45,,67,,56,,63,,,72,67,,,,34,56,,,,,56,,,,,,,,,,,,,,45,,,,,
123465,57,454,,67,,56,,63,,,72,67,,,,34,56,,,,,56,,,,,,,,,,,,,,45,,,,,
123466,57,45,,674,,56,,63,,,72,67,,,,34,56,,,,,56,,,,,,,,,,,,,,45,,,,,124

这是我的代码:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(void)

    {
    int lines_allocated = 1000;
    int max_line_len = 150;
    double c[42][1000];
    char **words = (char **)malloc(sizeof(char*)*lines_allocated);
    if (words==NULL)
        {
        fprintf(stderr,"Out of memory (1).\n");
        exit(1);
        }

    FILE *fp = fopen("full list.csv", "r");
    if (fp == NULL)
        {
        fprintf(stderr,"Error opening file.\n");
        exit(2);
        }

    int i;
    for (i=0;1;i++)
        {
        int j;

        if (i >= lines_allocated)
            {
            int new_size;

            new_size = lines_allocated*2;
            words = (char **)realloc(words,sizeof(char*)*new_size);
            if (words==NULL)
                {
                fprintf(stderr,"Out of memory.\n");
                exit(3);
                }
            lines_allocated = new_size;
            }
        words[i] = (char*)malloc(max_line_len);
        if (words[i]==NULL)
            {
            fprintf(stderr,"Out of memory (3).\n");
            exit(4);
            }
        if (fgets(words[i],max_line_len-1,fp)==NULL)
            break;

        for (j=strlen(words[i])-1;j>=0 && (words[i][j]=='\n' || words[i][j]=='\r');j--)

        words[i][j]='\0';
        }

    int j;
    int k=i;
    for(j = 0; j < k; j++)
    {
        printf("%s\n", words[j]);
        char *pptr = words[j];
        int l;
        for (l = 0; l < 42; l++)
        {
            char *ptr = strchr(pptr, ',');
            if (ptr) 
            {
                *ptr = 0;
                c[l][j] = atof(pptr);
                pptr = ptr + 1;
            }
        }    
    }

    int l;
    for (j = 0; j < k; j++)
    {
        printf("\n");

        for (l = 0; l < 42; l++)
        {
            printf("%.2f\t", c[l][j]);
        }
    }
    for (;i>=0;i--)
    free(words[i]);
    free(words);
    return 0;
    }

Answer 1

我认为你错过了一个简单的案例:应该是

#include <ctype.h>
...
        char *ptr = strchr(pptr, ',');
        if (ptr) 
        {
            *ptr = 0;
            c[l][j] = atof(pptr);
            pptr = ptr + 1;
        }
        else if (isdigit(*pptr)) {
            c[l][j] = atof(pptr);
        }