[Solved] How to print selected elements from file?

Introduction

Printing selected elements from a file can be a useful way to quickly access the information you need. Whether you are looking to print out a specific line from a text file or a specific column from a CSV file, there are a few different methods you can use to achieve this. In this article, we will discuss how to print selected elements from a file using various methods in Python. We will also discuss the advantages and disadvantages of each method. By the end of this article, you should have a better understanding of how to print selected elements from a file.

Solution

Using Python, you can print selected elements from a file by using the following code:

with open(‘filename.txt’, ‘r’) as f:
for line in f:
elements = line.split()
if elements[0] == ‘element_to_print’:
print(elements[1])

with open("fk.txt") as file:   # Use file to refer to the file object
    data = file.readlines()
column1, column2 = [], []
for line in data:
    try:
        entry1, entry2 = line.split(' ')
        column1.append(int(entry1))
        column2.append(int(entry2))
    except ValueError:
        pass
print column1, column2

#include <stdio.h>

int main()
{
    FILE *fp;
    char ch;
    int line_num = 1;
    int find_result = 0;

    fp = fopen("test.txt", "r");

    if (fp == NULL) {
        return(-1);
    }

    while((ch = fgetc(fp)) != EOF) {
        if (ch == '\n') {
            line_num++;
        }

        if (find_result == 0) {
            if (ch == 'a') {
                find_result = 1;
            }
        }
        else {
            if (ch == 'b') {
                printf("Line Number [%d]\n", line_num);
                find_result = 0;
            }
        }
    }

    if (fp) {
        fclose(fp);
    }

    return(0);
}

This code snippet shows how to print selected elements from a file. The code begins by including the stdio.h header file and declaring a main function. The code then opens a file called test.txt in read mode and assigns the file pointer to the fp variable.

The code then enters a while loop which reads each character from the file until the end of the file is reached. The code checks if the character is a new line character and if so, increments the line_num variable. The code then checks if the character is an ‘a’ and if so, sets the find_result variable to 1. If the find_result variable is 1, the code checks if the character is a ‘b’ and if so, prints the line number and sets the find_result variable to 0.

Finally, the code closes the file and returns 0. This code snippet shows how to print selected elements from a file.