when to use import statements in the header, when to use import statements in the blocks where they are used?
d at davea.name
Wed Feb 8 03:05:15 CET 2012
On 02/07/2012 08:48 PM, Lei Cheng wrote:
> Hi all,
> In a py file, when to use import statements in the header, when to use
> import statements in the blocks where they are used?
> What are the best practices?
Best practice is to put all the imports at the beginning of the module,
so they are easy to spot.
If you put an import inside a function, it gets re-executed each time
the function is called, which is a waste of time. Not too much, since
import first checks sys.modules to see if it's already loaded.
Also, avoid the from xxx import * form, as it pollutes the
namespace. And it makes it hard to figure out where a particular name
I believe these and other best practices can be found in pep8.
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