Question

So, I want to run a Python program with a home-directory install of PyProj from PHP. The PHP and Python are simple, but I include them below for completeness.

I’ve tested running Python manually using both sys.path.append and PYTHONPATH to specify the location of the package. Both of these methods work.

However, when I shell_exec the script from PHP, I’m told ImportError: No module named pyproj.

A recursive check of the file system reveals that everything is read/executable by user, group, and other.

Any thoughts on why this I can’t get this to run?

I’m calling it in a PHP script as follows

<?php
        putenv('PYTHONPATH="/home/userperson/public_html/lib64/python2.4/site-packages"');
        $ret=shell_exec("./bob");
        print $ret;
?>

The Python program is simple.

#!/usr/bin/python
import pyproj
import sys
sys.path.append("/home/userperson/public_html/lib64/python2.4/site-packages")
surfproj = pyproj.Proj(proj='lcc',lat_1=40,lat_2=50,lon_0=-95,lat_0=40,ellps='WGS84')
x,y=surjproj(-95,45)
print x

Answer 1

A good way to solve a problem like this is to print the sys.path from a Python script in this environment and check what the current path is:

 #!/usr/bin/python
 import sys
 print sys.path

My guess is that it will containt '"/home/userperson/public_html/lib64/python2.4/site-packages"' (note the superfluous double quotes).

The documentation of putenv($setting) doesn’t say anything about supporting shell syntax, quotes or escaping inside the setting, so any characters present in the strings would no doubt end in the value of the environmental variable. A possible fix for the issue would be:

putenv('PYTHONPATH=/home/userperson/public_html/lib64/python2.4/site-packages');

Another useful hint would be to put the path in a separate variable, and just do putenv("PYTHONPATH=$pythonpath") or putenv("PYTHONPATH=" . implode(':', $pythonpath)), as this would allow you to check if the paths exist from your PHP script with file_exists.

Older versions of PHP might have issue if safe_mode is enabled and PYTHONPATH isn’t in the safe_mode_allowed_env_vars, but hopefully you’re not running on a server configured like that.