eval in python

 Python eval() Function

The eval () Function of python can be used to evaluate and return the result of expression given as string. 

for example 

>> eval('8+9')

output 

17

Similarly, following code fragment 

 

    y=eval("3*10")

print (y)

output 

30

Since , eval() can interpret an expression given as string , you can use it with input() too.

example

var1=eval(input(enter value))

print(var1,type(var1))

output

enter value  9+8

17 <class 'int'>

See, the eval() not only interpreted the string ("15+3") as 18 but also stored the result as int value. thus 

with eval (), if enter an integer or float value ,it will interpret the values as the intended type .

example

var1=eval(input(enter value))

print(var1,type(var1))

output

enter value  5+7

12 <class 'int'>

example

var1=eval(input(enter value))

print(var1,type(var1))

output

enter value  2.5+7

9.5 <class 'float'>

you can use eval() enter a list or also .Use [ ] to enter and ( ) to enter tuple values 

example

var1=eval(input(enter value))

print(var1,type(var1))

output

enter value  [1,2,3]

[1,2,3]<class 'list'>