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eval Function

The eval() function evaluates the specified expression (code), and runs it. The syntax is as below

eval(expression, globals, locals)
Parameter Description
expression A String that will be evaluated as Python expression
globals (Optional) A dictionary that holds global parameters
locals (Optional) A dictionary that holds local parameters

Let's drop the extra quote. 

>>> x = '"55"'
>>> eval(x)
'55'

The following performs the specified operations: 

>>> x = 2
>>> eval('x * x +3')
7

Let's transfer a dictionary of functions and simply choose from it. 

list = {'Plus': lambda x, y: x + y, 'Minus': lambda x, y: y - x}
print(eval('Minus(2,8)', list))


>>> list = {'Plus': lambda x, y: x + y, 'Minus': lambda x, y: y - x}
>>> print(eval('Minus(2,8)', list))
6