Importing in Python just adds stuff to your namespace. How you qualify imported names is the difference between import foo and from foo import bar.
In the first case, you would only import the module name foo, and that's how you would reach anything in it, which is why you need to do foo.bar(). The second case, you explicitly import only bar, and now you can call it thus: bar().
from foo import * will import all importable names (those defined in a special variable __all__) into the current namespace. This, although works - is not recommend because you may end up accidentally overwriting an existing name.
foo = 42
from bar import * # bar contains a `foo`
print foo # whatever is from `bar`
The best practice is to import whatever you need:
from foo import a,b,c,d,e,f,g
Or you can alias the name
import foo as imported_foo
Bottom line - try to avoid from foo import *.