CODEWITHSUNDEEP
pythonpython-3.x
Lonnie Price
Lonnie Price

Reputation: 10455

Reloading module giving NameError: name 'reload' is not defined

I'm trying to reload a module I have already imported in Python 3. I know that you only need to import once and executing the import command again won't do anything.

Executing reload(foo) is giving this error:

Traceback (most recent call last):
    File "(stdin)", line 1, in (module)
    ...
NameError: name 'reload' is not defined

What does the error mean?

Upvotes: 184

Views: 191305

Answers (7)

user6830669
user6830669

Reputation: 177

If you don't want to use external libs, then one solution is to recreate the reload method from python 2 for python 3 as below. Use this in the top of the module (assumes python 3.4+).

import sys
if(sys.version_info.major>=3):
    def reload(MODULE):        
        import importlib
        importlib.reload(MODULE)

BTW reload is very much required if you use python files as config files and want to avoid restarts of the application.....

Upvotes: 4

Patrick José Pereira
Patrick José Pereira

Reputation: 1806

For python2 and python3 compatibility, you can use:

# Python 2 and 3
from imp import reload
reload(mymodule)

Upvotes: 5

Alleo
Alleo

Reputation: 8548

I recommend using the following snippet as it works in all python versions (requires six):

from six.moves import reload_module
reload_module(module)

Upvotes: 13

Joey Wilhelm
Joey Wilhelm

Reputation: 5819

To expand on the previously written answers, if you want a single solution which will work across Python versions 2 and 3, you can use the following:

try:
    reload  # Python 2.7
except NameError:
    try:
        from importlib import reload  # Python 3.4+
    except ImportError:
        from imp import reload  # Python 3.0 - 3.3

Upvotes: 41

Alex Martelli
Alex Martelli

Reputation: 882851

reload is a builtin in Python 2, but not in Python 3, so the error you're seeing is expected.

If you truly must reload a module in Python 3, you should use either:

Upvotes: 255

Kevin
Kevin

Reputation: 6711

For >= Python3.4:

import importlib
importlib.reload(module)

For <= Python3.3:

import imp
imp.reload(module)

For Python2.x:

Use the in-built reload() function.

reload(module)

Upvotes: 100

user57823
user57823

Reputation: 

import imp
imp.reload(script4)

Upvotes: 49

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