tutorial: fix hash-bang in section on programming

[jhpalmieri]

The section in the tutorial on standalone scripts needs some fixing. It suggests writing a script starting with

#!/usr/bin/env sage -python

import sys
from sage.all import *
...

But on sage.math.washington.edu, and probably on other linux systems, /usr/bin/env doesn't handle multiple arguments very well. I think that replacing the first line with #!/usr/bin/env sage should work.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​99c96af

tutorial: fix hash-bang in section on programming

[kcrisman]

This doesn't fix what is in the description, which is fixed already, I guess. What I don't understand is why you remove the -python, since otherwise there is no need for

from sage.all import *

is there? Maybe I'm missing something.

[jhpalmieri]

I think this is the right thing to do. First, we should certainly not advocate #!/usr/bin/env followed by multiple arguments. Second, I just tried the script from the tutorial but with just #!/usr/bin/env sage at the top. It worked fine, but it didn't work if I removed from sage.all import *:

Traceback (most recent call last):
  File "./my_script", line 10, in <module>
    print factor(sage_eval(sys.argv[1]))
NameError: name 'factor' is not defined

[jhpalmieri]

In particular, I'm happy to give this a positive review. Karl-Dieter, any objections?

[kcrisman]

No objections if it works this way and doesn't otherwise! I didn't do anything useful here so I'm taking my name off, though.