web2py: module function that behaves normally in shell fails browser mode - function

Question

I have a very simple helper function that helps creates column definitions for a javascript framework I"m using.
def tocol(fields,title=None,width=None,attributes=None):
cols = dict((name,eval(name)) for name in ['title','width','attributes'] if eval(name) is not None)
cols["field"] = fields
return cols
when I try this in a web2py shell the result is as I'd expect:
In [15]: col = tocol(attr.columns.tolist())
In [16]: col
Out[16]: {'field': ['l1', 'pw', 'bw', 'tilt']}
but when I try the same thing in a view I get the following traceback:
Traceback (most recent call last):
File "/home/tahnoon/web2py/gluon/restricted.py", line 224, in restricted
exec ccode in environment
File "/home/tahnoon/web2py/applications/apollo/controllers/performance.py", line 788, in <module>
File "/home/tahnoon/web2py/gluon/globals.py", line 392, in <lambda>
self._caller = lambda f: f()
File "/home/tahnoon/web2py/applications/apollo/controllers/performance.py", line 561, in pa_equity
cols = tocol(attr.columns.tolist())
File "applications/apollo/modules/helpers.py", line 33, in tocol
cols = dict((name,eval(name)) for name in ['title','width','attributes'] if eval(name) is not None)
File "applications/apollo/modules/helpers.py", line 33, in <genexpr>
cols = dict((name,eval(name)) for name in ['title','width','attributes'] if eval(name) is not None)
File "<string>", line 1, in <module>
NameError: name 'title' is not defined
Might anyone have any idea what is going wrong here? Pretty mystified.
Thanks

Answer 1

It looks like you're just trying to remove None values from a dictionary, so instead, why not just create a function to do that:
def remove_none(d):
[d.pop(key) for key in d.keys() if d[key] is None]
Then you can do:
col = remove_none(dict(field=attr.columns.tolist(),
title=None, width=None, attributes=None))
Or if you want to enter the arguments directly::
def remove_none_dict(**d):
[d.pop(key) for key in d.keys() if d[key] is None]
return d
col = remove_none_dict(field=attr.columns.tolist(),
title=None, width=None, attributes=None))