Question

我无法使用exec（）创建局部变量。我尝试了exec(instruction)，exec(instruction, locals())，但是没有用。只有exec(instruction, globals())有效，但是变量是在全局级别创建的，这不是我想要的。这是一段说明我的问题的代码

# remove all variables previously stored in the environment
for name in dir():
    if not name.startswith('_'):
        del globals()[name]

def f1():
    instruction = 'bar=1'
    # exec(instruction) # NameError: name 'bar' is not defined
    # exec(instruction, locals()) # NameError: name 'bar' is not defined
    exec(instruction, globals()) # okish, but not the way I want cause bar is built at the globa scope
    print('bar={} from inside f1'.format(bar))


print('test for global variable')
instruction = 'foo=1'
exec(instruction)
print('foo={}'.format(foo))

print('test for local variable')
f1()

print('bar={} from the outside'.format(bar)) # should raise NameError here but it doesn't

如何在Python 3.x中将“ locals（）”与exec结合使用？

0 个答案: