Python Pocket Reference, 3rd Edition

Specific Statements

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The from Statement

from [package.]* module import name [,name]*

from [package.]* module import *

from [package.]* module import name as othername

from [package.]* module import (name1, name2,

name3, name4)

The from statement imports variable names from a module so

that you can use those names later without the need to qual-

ify them with their module name. The

from mod import * for-

mat copies all names assigned at the top level of the module,

except names with a single leading underscore or names not

listed in the module’s

__all__ list-of-strings attribute (if

defined).

If used, the

as clause creates a name synonym. If used,

package import paths work the same as in import statements

(e.g.,

from dir1.dir2.mod import X), but the package path

needs to be listed only in the

from itself. Due to new scoping

rules, the

* format generates warnings in Version 2.2 if it

appears nested in a function or class.

As of Python 2.4, the names being imported from a module

can be enclosed in parentheses to span multiple lines with-

out backslashes.

The

from statement is also used to enable future (but still

experimental) language additions, with

from __future__

import featurename

. This format must appear only at the top

of a module file (preceded only by an optional doc string).

The class Statement

class name [ ( super [, super]* ) ]:

suite

The class statement makes new class objects, which are fac-

tories