Executing a C program in python?
I have this C program, at least I think it is (files: spa.c, spa.h). Is there any way I can execute this script from Python WITHOUT passing extra arguments to the Python interpreter (if not, what would the arguments be?)
Update: Thanks for your replies. The source code can be found at http://www.nrel.gov/midc/spa/#register
(Please do not be scared by the 'register' in the url, if you fill in the form, you can immediately download the files (no validation mails, etc) I will try your suggestions and report back with the results.
Update 2: I compile开发者_JS百科d the source code using gcc, but now it gives me a permission denied when trying to call(), even when running python as root (im on Ubuntu 10:10).
Update 3 [Errno 8] Exec format error
Update 4 Ok, I got it working. Program outputs values using printf:
>>> call(['/path'])
Julian Day: 2452930.312847
L: 2.401826e+01 degrees
B: -1.011219e-04 degrees
R: 0.996542 AU
H: 11.105902 degrees
Delta Psi: -3.998404e-03 degrees
Delta Epsilon: 1.666568e-03 degrees
Epsilon: 23.440465 degrees
Zenith: 50.111622 degrees
Azimuth: 194.340241 degrees
Incidence: 25.187000 degrees
Sunrise: 06:12:43 Local Time
Sunset: 17:20:19 Local Time
Thanks all!
There is no such thing as a C script. If you meant a C program you need to compile spa.c
and spa.h
into an executable before running it.
If you use GCC in Linux or Mac OS X:
$ gcc -Wall spa.c -o spa
Will get you an executable named spa
.
After that, you can run spa
program from your Python script with:
from subprocess import call
call(["./spa", "args", "to", "spa"])
cinpy comes close using the awesome combination of tcc and ctypes
The following code is ripped from cinpy_test.py included in the package.
import ctypes
import cinpy
# Fibonacci in Python
def fibpy(x):
if x<=1: return 1
return fibpy(x-1)+fibpy(x-2)
# Fibonacci in C
fibc=cinpy.defc("fib",
ctypes.CFUNCTYPE(ctypes.c_long,ctypes.c_int),
"""
long fib(int x) {
if (x<=1) return 1;
return fib(x-1)+fib(x-2);
}
""")
# ...and then just use them...
# (there _is_ a difference in the performance)
print fibpy(30)
print fibc(30)
C is not a scripting language. You have to compile spa.c into an executable. You don't say your OS, but if Mac or Linux, try
gcc spa.c -o spa
If that works, you now have a executable named spa. You can use python's os.system()
to call it.
there is no such thing as a C script you need to compile C programs... if you compile to an executable, you can execute it using os.system(CommandLine)
Question is old still I felt one important part is missing!
C code can be compiled AND executed within Python script:
#include <iostream>
using namespace std;
int main(){
cout<<"Hello World\n";
return 1;
}
import subprocess
subprocess.call(["g++", "hello_world.cpp"]) # OR gcc for c program
tmp=subprocess.call("./a.out")
print("printing result")
print(tmp)
$ python main.py
Hello World
printing result
1
I referred to the post on Quora: https://www.quora.com/How-do-I-write-a-Python-script-to-run-a-C-program
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