What s the difference between a Python module and a Python package

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What s the difference between a Python module and a Python package   See also  What  39 s the difference between  quot package quot  and  quot module quot   for other languages

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From the Python glossary       It   s important to keep in mind that all packages are modules  but not all modules are packages  Or put another way  packages are just a special kind of module  Specifically  any module that contains a   path   attribute is considered a package     Python files with a dash in the name  like my-file py  cannot be imported with a simple import statement  Code-wise  import my-file is the same as import my - file which will raise an exception  Such files are better characterized as scripts whereas importable files are modules

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A late answer  yet another definition      A package is represented by an imported top-entity which could either   be a self-contained module  or the   init   py special module as the   top-entity from a set of modules within a sub directory structure    So physically a package is a distribution unit  which provides one or more modules

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A module is a single file  or files  that are imported under one import and used   e g   import my module   A package is a collection of modules in directories that give a package hierarchy   from my package timing danger internets import function of love   Documentation for modules  Introduction to packages

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Any Python file is a module  its name being the file s base name without the  py extension  A package is a collection of Python modules  while a module is a single Python file  a package is a directory of Python modules containing an additional   init   py file  to distinguish a package from a directory that just happens to contain a bunch of Python scripts  Packages can be nested to any depth  provided that the corresponding directories contain their own   init   py file   The distinction between module and package seems to hold just at the file system level  When you import a module or a package  the corresponding object created by Python is always of type module  Note  however  when you import a package  only variables functions classes in the   init   py file of that package are directly visible  not sub-packages or modules  As an example  consider the xml package in the Python standard library  its xml directory contains an   init   py file and four sub-directories  the sub-directory etree contains an   init   py file and  among others  an ElementTree py file  See what happens when you try to interactively import package modules    gt  gt  gt  import xml  gt  gt  gt  type xml   lt type  module  gt   gt  gt  gt  xml etree ElementTree Traceback  most recent call last     File   lt stdin gt    line 1  in  lt module gt  AttributeError   module  object has no attribute  etree   gt  gt  gt  import xml etree  gt  gt  gt  type xml etree   lt type  module  gt   gt  gt  gt  xml etree ElementTree Traceback  most recent call last     File   lt stdin gt    line 1  in  lt module gt  AttributeError   module  object has no attribute  ElementTree   gt  gt  gt  import xml etree ElementTree  gt  gt  gt  type xml etree ElementTree   lt type  module  gt   gt  gt  gt  xml etree ElementTree parse  lt function parse at 0x00B135B0 gt    In Python there also are built-in modules  such as sys  that are written in C  but I don t think you meant to consider those in your question

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First  keep in mind that  in its precise definition  a module is an object in the memory of a Python interpreter  often created by reading one or more files from disk  While we may informally call a disk file such as a b c py a  module   it doesn t actually become one until it s combined with information from several other sources  such as sys path  to create the module object     Note  for example  that two modules with different names can be loaded from the same file  depending on sys path and other settings  This is exactly what happens with python -m my module followed by an import my module in the interpreter  there will be two module objects    main   and my module  both created from the same file on disk  my module py    A package is a module that may have submodules  including subpackages   Not all modules can do this  As an example  create a small module hierarchy     mkdir -p a b   touch a b c py   Ensure that there are no other files under a  Start a Python 3 4 or later interpreter  e g   with python3 -i  and examine the results of the following statements   import a a                   lt module  a   namespace  gt  a b                AttributeError  module  a  has no attribute  b  import a b c a b                 lt module  a b   namespace  gt  a b c               lt module  a b c  from   home cjs a b c py  gt    Modules a and a b are packages  in fact  a certain kind of package called a  namespace package   though we wont  worry about that here   However  module a b c is not a package  We can demonstrate this by adding another file  a b py to the directory structure above and starting a fresh interpreter   import a b c   ImportError  No module named  a b c    a b  is not a package import a b a                   lt module  a   namespace  gt  a   path            NamespacePath        a    a b                 lt module  a b  from   home cjs tmp a b py  gt  a b   path         AttributeError   module  object has no attribute    path      Python ensures that all parent modules are loaded before a child module is loaded  Above it finds that a  is a directory  and so creates a namespace package a  and that a b py is a Python source file which it loads and uses to create a  non-package  module a b  At this point you cannot have a module a b c because a b is not a package  and thus cannot have submodules   You can also see here that the package module a has a   path   attribute  packages must have this  but the non-package module a b does not

[python] What's the difference between a Python module and a Python package?

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