executing code with imports fails

[bradharmon]

Maybe I'm missing something really basic, but executing code with imports fails with an error saying that the import is not defined

import pushy

source = """
import math
def sqrt(x)
   return math.sqrt(x)
"""

conn = pushy.connect("local:")

namespace = {}
conn.execute(source, locals=namespace, globals=None)
print namespace["sqrt"](144)

conn.close()

pushy.protocol.proxy.ExceptionProxy: global name 'math' is not defined

However if I run it with 'source' modified slightly, it works fine:

source = """
import math
def sqrt(x)
   global math
   return math.sqrt(x)
"""

I would like to be able to get rid of the extra 'global' declaration, however nothing I've tried seems to work.

[axw]

Hi Brad,

Please try this:

namespace = conn.eval("{}")
conn.execute(source, globals=namespace) # locals defaults to globals

The CPython runtime doesn't like it when you try to use a foreign dictionary object as the globals parameter to eval. The change I've suggested creates a dictionary in the remote process, and then calls eval with that; thus when eval is called in the remote process it is operating on a dictionary local to its interpreter (hope that makes sense!)

Thanks for filing the issue. Please let me know how you get on.

Cheers, Andrew

[bradharmon]

This worked great! Thanks

Along the same lines, I'm having difficulty loading remote code into a local module:

source = """
import math
def sqrt(x):
   return math.sqrt(x)
"""

module = conn.modules.imp.new_module('test')
conn.execute(source, globals=module.__dict__)
module.sqrt(144)

pushy.protocol.proxy.ExceptionProxy: 'module' object has no attribute 'sqrt'

I've also tried to execute it with 'globals=namespace' and then load that dict into a local module, but that has issues as well:

module = imp.new_module('test')
namespace = conn.eval("{}")
conn.execute(source, globals=namespace)

module.__dict__ = namespace

module.__dict__ = namespace

TypeError: readonly attribute

What are your suggestions for this use case? I really appreciate the help.

Thanks,

Brad

[bradharmon]

manually copying all values from the namespace dict into module.dict seems to work. Is this the suggested method for accomplishing this?

import pushy
import imp

source = """
import math
def sqrt(x):
   return math.sqrt(x)
"""

conn = pushy.connect("local:")

namespace = conn.eval("{}")
conn.execute(source, globals=namespace)

#create new module and copy namespace dict into module dict
module = imp.new_module('test')
for key, value in namespace.items():
   module.__dict__[key] = value

del namespace
print module.sqrt(144)

conn.close()

[axw]

Just so I'm clear on the intentions of the code: you're trying to create a module in process A that contains methods that will be executed in process B?

It's a bit ugly IMHO, but that's pretty much how it goes. Ideally you'd just set globals=module.dict, but then you have the problem of it not being a real dict in the remote process.

[bradharmon]

Yes, that's the goal. I want the ability to remotely import local code. I have code where multiple classes need to interact on a remote box and this seems like the easiest way

[axw]

Okey dokey. I haven't personally done (exactly) this before, so you may come against more ugliness along the way. I'll leave this issue open a while longer in case you want some more input.

[axw]

I assume this can be closed now, please reopen if you encounter any more problems.