Python cannot find the executed function after exec()

Question

I cannot find the executed function even after the excution.

This is the function:

# function illustrating how exec() functions.
def exec_code():
    LOC = """ 
def factorial(num): 
    fact=1 
    for i in range(1,num+1): 
        fact = fact*i 
    return fact 
print(factorial(5)) 
"""
    exec(LOC) 
    print(factorial)

# Driver Code 
exec_code() 

However, this yields an error:

NameError                                 Traceback (most recent call last)
<ipython-input-10-d403750cbbfb> in <module>
     13 
     14 # Driver Code
---> 15 exec_code()

<ipython-input-10-d403750cbbfb> in exec_code()
     10 """
     11     exec(LOC)
---> 12     print(factorial)
     13 
     14 # Driver Code

NameError: name 'factorial' is not defined

I really would like to execute a string function as the above pattern. Does anyone know how to solve it? If exec is not recomanded, are there any other solutions?

Answer 1

According to the docs for exec(object[, globals[, locals]])

https://docs.python.org/3/library/functions.html#exec

Note The default locals act as described for function locals() below: modifications to the default locals dictionary should not be attempted. Pass an explicit locals dictionary if you need to see effects of the code on locals after function exec() returns.

---

Therefore, you need to pass your own locals dict in as globals and locals:

mylocals = {}
exec(your_code, mylocals, mylocals)

Then you can call it through the mylocals:

print(mylocals['factorial']())

Answer 2

You can give globals() to the exec call to make it add the function to the current module:

exec(LOC,globals())