python: importlib.import_module("time") but time is not defined globally

Question

In order to add to my program (in python 2.7) a check for available modules, I added the following code in place of the classical import (the idea being to help someone to locate & add extra modules):

mymodules = ['socket', 'requests', 'simplejson', 'pickle', 'IPy',
    'pygeoip', 'urllib', 'time', 'urllib2', 'StringIO', 'gzip', 'os']

import sys, importlib   # these ones should be available, otherwise bad luck :)
for module in mymodules:
    try:
        importlib.import_module(module)
        print "importing ", module
    except:
        if module == "requests": info = "http://docs.python-requests.org/en/latest/user/install/#install or aptitude install python-requests"
        elif module == "requests": info = "https://github.com/simplejson/simplejson or aptitude install python-simplejson"
        elif module == "IPy": info = "https://github.com/haypo/python-ipy/wiki or aptitude install python-ipy"
        elif module == "pygeoip": info = "https://github.com/appliedsec/pygeoip or pip install pygeoip"
        else: info = "Oops, you should not see this - the description of the missing plugin is missing in the code"
        print "module {} is missing, see {}".format(module,info)
        sys.exit(0)

Later on my program crashes with NameError on a call to time.time() ('time' is not defined). I therefore tried to test module importing from scratch:

>>> import sys, importlib
>>> importlib.import_module("time")
<module 'time' (built-in)>
>>> print sys.modules.keys()
['copy_reg', 'sre_compile', '_sre', 'encodings', 'site', '__builtin__', 'sysconfig', '__main__', 'encodings.encodings', 'abc', 'importlib.sys', 'posixpath', '_weakrefset', 'errno', 'encodings.codecs', 'sre_constants', 're', '_abcoll', 'types', '_codecs', 'encodings.__builtin__', '_warnings', 'genericpath', 'stat', 'zipimport', '_sysconfigdata', 'warnings', 'UserDict', 'encodings.utf_8', 'sys', 'codecs', 'readline', '_sysconfigdata_nd', 'os.path', 'importlib', 'sitecustomize', 'signal', 'traceback', 'linecache', 'posix', 'encodings.aliases', 'time', 'exceptions', 'sre_parse', 'os', '_weakref']

time is there. Nevertheless:

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

Now with a classical import:

>>> import time
>>> print time.time()
1380831191.08

Why doesn't importlib.import_module("time") imports time in such a way that time.time() can be called?

Answer 1

From the docs:

The specified module will be inserted into sys.modules and returned.

In other words, import_module will not create a variable for you, you will have to do it yourself:

time = importlib.import_module('time')

Or, in your "dynamic" case:

globals()['time'] = importlib.import_module('time')

On a side note, why do you even do this? Why not just wrap a normal import in a try-except block?

Answer 2

I think importlib.import_module("time") returns an object, we need to assign it to a variable. Use that variable to invoke all the methods of time.

Try:

import sys, importlib

var_name = importlib.import_module("time")
print var_name.time()