Recipe 580701 revision 1

The D program, student_grades.d:

/*
student_grades.d
Author: Vasudev Ram
Web site: https://vasudevram.github.io
Blog: http://jugad2.blogspot.com
Product store: https://gumroad.com/vasudevram
Adapts code from:
http://nomad.so/2015/08/more-hidden-treasure-in-the-d-standard-library/
*/

import std.stdio;
import std.algorithm;
import std.array;
import std.conv;
import std.functional;

// Set up the functional pipeline by composing some functions.
alias sumString = pipe!(split, map!(to!(int)), sum);

void main(string[] args)
{
    // Data to be transformed:
    // Each string has the student name followed by 
    // their grade in 5 subjects.
    auto student_grades_list = 
    [
        "A 1 2 3 4 5",
        "B 2 3 4 5 6",
        "C 3 4 5 6 7",
        "D 4 5 6 7 8",
        "E 5 6 7 8 9",
    ];

    // Transform the data for each student.
    foreach(student_grades; student_grades_list) {
        auto student = student_grades[0]; // name
        auto total = sumString(student_grades[2..$]); // grade total
        writeln("Grade total for student ", student, ": ", total);
    }
}

Compile it with:

$ dmd student_grades.d

The Python program is StdinToPDF.py which is part of the xtopdf toolkit, at:

http://bitbucket.org/vasudevram/xtopdf

Code for StdinToPDF.py is below. It requires xtopdf / PDFWriter, available from the above URL.

# StdinToPDF.py

# Read the contents of stdin (standard input) and write it to a PDF file
# whose name is specified as a command line argument.
# This program is part of the xtopdf toolkit:
#     https://bitbucket.org/vasudevram/xtopdf

import sys
from PDFWriter import PDFWriter

try:
    with PDFWriter(sys.argv[1]) as pw:
        pw.setFont("Courier", 12)
        for lin in sys.stdin:
            pw.writeLine(lin)
except Exception, e:
    print "ERROR: Caught exception: " + repr(e)
    sys.exit(1)

Run it with:

$ student_grades | python StdinToPDF.py sg.pdf

The student grade results will now be in the PDF file sg.pdf.

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• revision 1 (7 years ago)