The `eval` function in Python allows you to execute a string-based Python expression dynamically. This can be useful in various scenarios where you need to evaluate expressions that are not known until runtime.

```python

eval(expression, globals=None, locals=None)

* expression: String is parsed and evaluated as a Python expression

* globals [optional]: Dictionary to specify the available global methods and variables.

* locals [optional]: Another dictionary to specify the available local methods and variables.

Example 1:

result = eval('2 + 3 * 4')

print(result) # Output: 14

Example 2:

x = 10

expression = 'x * 2'

result = eval(expression, {'x': x})

print(result) # Output: 20

Example 3:

x = 10

def multiply(a, b):

return a * b

expression = 'multiply(x, 5) + 2'

result = eval(expression)

print("Result:",result) # Output: Result:52

Example 4:

expression = input("Enter a Python expression: ")

result = eval(expression)

print("Result:", result)

Example 5:

import numpy as np

a=np.random.randint(1,9)

b=np.random.randint(1,9)

operations=["*","-","+"]

op=np.random.choice(operations)

expression=str(a)+op+str(b)

correct_answer=eval(expression)

given_answer=int(input(str(a)+" "+op+" "+str(b)+" = "))

if given_answer==correct_answer:

print("Correct")

else:

print("Incorrect")

print("correct answer is :" ,correct_answer)

The eval function is a powerful tool in Python that allows for dynamic evaluation of expressions.

- [Eval Function](eval_function.md)