Package Structure

Note that this page is stale; links need to be updated, instructions about import * need to be updated.

Most NLTK code is structured into packages, which have the following structure:

1. all modules * opening comment with package name, copyright, license, authors
2. __init__.py * package-level docstring * import statements that import module names (but not api or util) into the package namespace: from module import (name1, ...) (for all modules in the package) * mappings from deprecated functions to current functions, with deprecation decorators * example: https://github.com/nltk/nltk/blob/develop/nltk/chunk/__init__.py
3. api.py * define any interface classes that are used in other modules * this should be imported into other modules * (this filename is misleading as it is not an external API) * example: https://github.com/nltk/nltk/blob/develop/nltk/chunk/api.py
4. util.py * common utilities shared by modules in this package * example: https://github.com/nltk/nltk/blob/develop/nltk/chunk/util.py
5. module.py (where "module" is the name of a module) * imports in three blocks: standard library and third party imports, nltk imports, package-local imports * imports from this package have the form from nltk.package import name (and not from nltk.package.other_module import name, for names that are imported into __init__.py; to facilitate reorganisation of the internals of a package) * imports from other nltk packages are fully qualified, e.g. from nltk import tokenize