list comprehension in exec with empty locals: NameError

Question

Consider the following snippet:

def bar():
    return 1
print([bar() for _ in range(5)])

It gives an expected output [1, 1, 1, 1, 1]<

Answer 1

Edit

To answer your edited question, user @Hendrik Makait said bar is not in the scope of list comprehension:

def foo():
    def bar():
        return 1
    print('bar' in globals()) # False, because the scope of foo and bar are diferents, foo is globals() scope, bar are in the scope of foo
    print('bar' in locals()) # True
    print(['bar' in locals() for _ in [1]]) # [False], because a new implicit scope is defined in list comprehension, as user @Antti Haapala said
    print([bar() for _ in [1, 2]]) # [1, 1]

To answer the original question:

If you create two different dictionaries, it wont recognize the local and globals definitions, the variables are not updated as @PM 2Ring said:

exec("""
def bar():
    return 1
print(bar())
print("bar" in globals())
print("bar" in locals())
print([bar() for _ in range(5)])
""", {},{})

it prints:

1
False #not in globals
True
Traceback (most recent call last):
  File "python", line 17, in 
  File "", line 7, in 
  File "", line 7, in 
NameError: name 'bar' is not defined

A way to do it, is update the variables, like this globals().update(locals()):

exec("""
def bar():
    return 1
globals().update(locals())
print("bar" in globals())
print("bar" in locals())
print([bar() for _ in range(5)])
""", {}, {})

wich gives:

True
True
[1, 1, 1, 1, 1]

But, if you remove the dictionaries, or create one and give it to the exec function as same parameter, it works:

d={}

exec("""
def bar():
    return 1
print("bar" in globals())
print("bar" in locals())
print([bar() for _ in range(5)])
""",d,d)

it prints:

True
True
[1, 1, 1, 1, 1]

That's why you get the error, it could't find your function in the globals

Or simply, don't give the parameters:

exec("""
def bar():
    return 1
print(bar())
print("bar" in globals())
print("bar" in locals())
print([bar() for _ in range(5)])
""")

Cause the same efect.