The exec and eval statements

The exec statement is used to execute Python statements which are stored in a string or file. For example,
we can generate a string containing Python code at runtime and then execute these statements using
the exec statement. A simple example is shown below.

>>> exec 'print "Hello World"'
Hello World

The eval statement is used to evaluate valid Python expressions which are stored in a string. A simple
example is shown below.

>>> eval('2*3')
6