Evaluating Python code without any preparsing

class sage.misc.python.Python

Allows for evaluating a chunk of code without any preparsing.

eval(x, globals, locals=None)

Evaluate x with given globals; locals is completely ignored. This is specifically meant for evaluating code blocks with %python in the notebook.

INPUT:

x – a string globals – a dictionary locals – completely IGNORED

EXAMPLES:

sage: from sage.misc.python import Python
sage: python = Python()
sage: python.eval('2+2', globals())
4
''

Any variables that are set during evaluation of the block will propagate to the globals dictionary.

sage: python.eval('a=5\nb=7\na+b', globals())
12
''
sage: b
7

The locals variable is ignored – it is there only for completeness. It is ignored since otherwise the following won’t work:

sage: python.eval("def foo():\n return 'foo'\nprint foo()\ndef mumble():\n print 'mumble',foo()\nmumble()", globals())
foo
mumble foo
''
sage: mumble
<function mumble at ...>