a = 100

def foo(x):
    print "x is {}, a is {}".format(x,a)
    print "locals:" + '*' * 10
    print locals()
    print "globals:" + '*' * 10
    print globals()
    print abs(1)

def main():

    source = 'foo(x)'
    l = {'foo':foo, 'x':1}
    exec(source,{'__builtins__': None}, l)

if __name__ == '__main__':
    main()

x is 1, a is 100
locals:**********
{'x': 1}
globals:**********
{'a': 100, 'main': <function main at 0x7f68c1d37c80>, '__builtins__': <module '__builtin__' (built-in)>, '__file__': 'play/eval_test.py', '__package__': None, '__name__': '__main__', 'foo': <function foo at 0x7f68c1d37c08>, '__doc__': None}
1