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__import__

Description

Imports a module.

Syntax

__import__ (name[, globals[, locals[, fromlist[, level]]]])

name
Required. Name of the module to import.
globals
Optional. Dictionary of global names used to determine how to interpret the name in a package context.
locals
Optional. Dictionary of local names names used to determine how to interpret the name in a package context. The standard implementation does not use its locals argument at all, and uses its globals only to determine the package context of the import statement.
fromlist
Optional. The fromlist gives the names of objects or submodules that should be imported from the module given by name.
level
Optional. level specifies whether to use absolute or relative imports. The default is -1 which indicates both absolute and relative imports will be attempted. 0 means only perform absolute imports. Positive values for level indicate the number of parent directories to search relative to the directory of the module calling __import__().

Return Value

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Time Complexity

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Note

This is an advanced function that is not needed in everyday Python programming, unlike importlib.import_module().

Remarks

This function is invoked by the import statement. It can be replaced (by importing the __builtin__ module and assigning to __builtin__.__import__) in order to change semantics of the import statement, but nowadays it is usually simpler to use import hooks (see PEP 302). Direct use of __import__() is rare, except in cases where you want to import a module whose name is only known at runtime.

When the name variable is of the form package.module, normally, the top-level package (the name up till the first dot) is returned, not the module named by name. However, when a non-empty fromlist argument is given, the module named by name is returned. For example, the statement import spam results in bytecode resembling the following code:

>>> spam = __import__('spam', globals(), locals(), [], -1)

The statement import spam.ham results in this call:

>>> spam = __import__('spam.ham', globals(), locals(), [], -1)

Note how __import__() returns the toplevel module here because this is the object that is bound to a name by the import statement.

On the other hand, the statement from spam.ham import eggs, sausage as saus results in

>>> _temp = __import__('spam.ham', globals(), locals(), ['eggs', 'sausage'], -1)
>>> eggs = _temp.eggs
>>> saus = _temp.sausage

Here, the spam.ham module is returned from __import__(). From this object, the names to import are retrieved and assigned to their respective names.

If you simply want to import a module (potentially within a package) by name, use importlib.import_module().

Example

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See Also

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