How does one do the equivalent of "import * from module" with Python's __import__ function?
Given a string with a module name, how do you import everything in the module as if you had called:
from mo开发者_开发问答dule import *
i.e. given string S="module", how does one get the equivalent of the following:
__import__(S, fromlist="*")
This doesn't seem to perform as expected (as it doesn't import anything).
Please reconsider. The only thing worse than import *
is magic import *
.
If you really want to:
m = __import__ (S)
try:
attrlist = m.__all__
except AttributeError:
attrlist = dir (m)
for attr in attrlist:
globals()[attr] = getattr (m, attr)
Here's my solution for dynamic naming of local settings files for Django. Note the addition below of a check to not include attributes containing '__' from the imported file. The __name__
global was being overwritten with the module name of the local settings file, which caused setup_environ()
, used in manage.py, to have problems.
try:
import socket
HOSTNAME = socket.gethostname().replace('.','_')
# See http://docs.python.org/library/functions.html#__import__
m = __import__(name="settings_%s" % HOSTNAME, globals=globals(), locals=locals(), fromlist="*")
try:
attrlist = m.__all__
except AttributeError:
attrlist = dir(m)
for attr in [a for a in attrlist if '__' not in a]:
globals()[attr] = getattr(m, attr)
except ImportError, e:
sys.stderr.write('Unable to read settings_%s.py\n' % HOSTNAME)
sys.exit(1)
The underlying problem is that I am developing some Django, but on more than one host (with colleagues), all with different settings. I was hoping to do something like this in the project/settings.py file:
from platform import node
settings_files = { 'BMH.lan': 'settings_bmh.py", ... }
__import__( settings_files[ node() ] )
It seemed a simple solution (thus elegant), but I would agree that it has a smell to it and the simplicity goes out the loop when you have to use logic like what John Millikin posted (thanks). Here's essentially the solution I went with:
from platform import node
from settings_global import *
n = node()
if n == 'BMH.lan':
from settings_bmh import *
# add your own, here...
else:
raise Exception("No host settings for '%s'. See settings.py." % node())
Which works fine for our purposes.
It appears that you can also use dict.update() on module's dictionaries in your case:
config = [__import__(name) for name in names_list]
options = {}
for conf in config:
options.update(conf.__dict__)
Update: I think there's a short "functional" version of it:
options = reduce(dict.update, map(__import__, names_list))
I didn't find a good way to do it so I took a simpler but ugly way from http://www.djangosnippets.org/snippets/600/
try:
import socket
hostname = socket.gethostname().replace('.','_')
exec "from host_settings.%s import *" % hostname
except ImportError, e:
raise e
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