Python: Essential Reference, Third Edition

eval(), exec, execfile(), and compile()

The eval(str [,globals [,locals]]) function executes an expression string and returns the result. For example:

a = eval('3*math.sin(3.5+x) + 7.2')

Similarly, the exec statement executes a string containing arbitrary Python code. The code supplied to exec is executed as if the code actually appeared in place of the exec statement. For example:

a = [3, 5, 10, 13]
exec "for i in a: print i"

Finally, the execfile(filename [,globals [,locals]]) function executes the contents of a file. For example:

execfile("foo.py")

All these functions execute within the namespace of the caller (which is used to resolve any symbols that appear within a string or file). Optionally, eval(), exec, and execfile() can accept ...