Python program Executing C++ Program Containing Arrays

Python program Executing C++ Program Containing Arrays

In our previous program to check whether a number is a palindrome number or not you have used only control structure statements. Now you are going to execute a C++ program containing array.

Write a C++ program to print Transpose of a matrix(2 D array).*/

//Now select File->New in Notepad and type the C++ program

#include <iostream>

using namespace std;

int main()

{

int a[3][3], i, j;

for(i=0; i<3; i++)

{

for(j=0; j<3; j++)

{ cout<<"enter the value for array["<<i+1<<"]"<<"["<<j+1<<"] :"; cin>>a[i][j];

}

}

system("cls");

cout<<"\n\nOriginal Array\n";

for(i=0; i<3; i++)

{

for(j=0; j<3; j++)

cout<<a[i][j]<<' ';

cout<<endl;

}

cout<<"\n\n The Transpose of Matrix\n";

for (int i = 0; i < 3; i++)

{

for (int j = 0; j < 3; j++)

cout<<a[j][i]<<' ';

cout<<endl ;

}

return 0;

}

// Save this file as trans_cpp.cpp

//Now select File→New in Notepad and type the Python program

#Save the File as transpose.py.Program that compiles and executes a .cpp file

#Python tanspose.py -i trans_cpp

import sys, os, getopt

def main(argv):

cpp_file = ''

exe_file = ''

opts, args = getopt.getopt(argv, "i:",['ifile='])

for o, a in opts:

if o in ("-i", "--ifile"):

cpp_file = a + '.cpp'

exe_file = a + '.exe'

run(cpp_file, exe_file)

def run(cpp_file, exe_file):

print("Compiling " + cpp_file)

os.system('g++ ' + cpp_file + ' -o ' + exe_file)

print("Running " + exe_file)

print("-------------------")

print

os.system(exe_file)

print

if __name__ =='__main__':

main(sys.argv[1:])

Output of the above program

Original Array

1 2 3

4 5 6

7 8 9

The Transpose of Matrix

1 4 7

2 5 8

3 6 9

You would have noticed the Python program used to execute the transpose of a matrix is also the same as what you have used in palindrome program. From this what you have understood?

The Python script (program) in this chapter is mainly used to read the C++ file along with the type of mode used like ‘i’/’o’. It Parses (splits) each value of the command line and pass as argument to the List called “opts”. The entire C++ code is referenced for reading by “long option ifile” along with the mode.

The List ‘o’ in “for loop” contains the mode (‘i’) and the variable ‘a’ contains the C++ file with its complete path (Example [<‘c:\pyprg\cpp_file’>,’ trans_cpp’ ]) The extensions like cpp/ exe are added by the Python script.

__name__ variable directs the program to start from the Python script’s “main” definition. The “main” definition does the Parsing and adding the extensions. The “run” definition invoke the “g++” compiler and creates the exe file. The system() command of “os” module executes the exe file and you will get the desired output. The file extensions are added by the Python script due to which you can even execute the C programs.