Exec and Eval in Python

eval and exec¶

Let us understand how we can use eval and exec in Python.

Typically we perform arithmetic operations like this a = b + c.
We can also use eval and exec for the same.
eval typically evaluates the expression. We need to assign the value to some variable when we use eval.
exec executes the statement.

In [1]:

b = 10

In [2]:

c = 20

In [3]:

a = b + c

In [4]:

Out[4]:

In [5]:

eval('b + c') # Typically we assign the result of eval to a variable or object

Out[5]:

In [6]:

exec('d = b + c') # variable or object will be created when we use exec

In [7]:

Out[7]:

In [8]:

def calc(a, b, op):
    return eval(f'{a} {op} {b}')

In [9]:

calc(1, 2, '+')

Out[9]:

In [10]:

calc(10, 20, '*')

Out[10]: