It is a bad idea to be importing everything from a Python package as a package is not a super-module -- it's a collection of modules grouped together. So you should just import what you need in that file. Also importing everything from package into your global namespace is going to cause a proliferation of names, and very likely conflicts among those names.That being said, there are still ways to do this. First one being manually importing everything from a package using import statements for every sub-module.  Another way, as the documentation at http://docs.python.org/tutorial/modules.html#importing-from-a-package - suggests, is that if you ... Read More

The "from module import *" statement is used to import all submodules from a Python package/module. For example, if you want to import all modules from your module(say nyModule) and do not want to prefix "myModule." while calling them, you can do it as follows:>>> from myModule import *Note that for any reasonable large set of code, if you import * you will likely be cementing it into the module, unable to be removed. This is because it is difficult to determine what items used in the code are coming from 'module', making it easy to get to the point ... Read More

Using namespace packages, you can distribute the sub-packages and modules of one package among many, independent distribution packages (referred to as distributions in this document to avoid ambiguity). In Python, a namespace package allows you to spread Python code among several projects. This is useful when you want to release related libraries as separate downloads. Creating a namespace package Currently, there are three methods for developing namespace packages. These methods are mentioned below. Use packages for native namespaces. The PEP 420 specification for this kind of namespace package states that Python 3.3 and later support it. If packages in ... Read More

This is basically the idea of a singleton object. So if you have instantiated an obect and want to access it across different module, you can use 2 approaches, first being you assign that variable to the module you imported under a variable name. For example, you have a object myobj instantiated and want to use it with module B, then you can do the following:>>> import B >>> B.myobj = myobjAnd inside module B, use it like any other global property. Another way is to accept this object as a parameter wherever required. For example, if you have a ... Read More

Yes, a function call (any function call, not just recursive ones) creates a new namespace. BUT, when given as parameters, OBJECTS are passed by reference.So, the new namespace get its own copy of this reference but it still refers to the same object as in the calling function, and if you change the content of that object, you will notice the change in the calling function.To be more specific, Whenever the Interpreter encounters a call to a function, its creates a frame object, which is pushed to a frame stack. Each time a frame is created, that frame is given ... Read More

Namespace is a way to implement scope. In Python, each package, module, class, function and method function owns a "namespace" in which variable names are resolved. When a function,  module or package is evaluated (that is, starts execution), a namespace is created. Think of it as an "evaluation context". When a function, etc., finishes execution, the namespace is dropped. The variables are dropped. Plus there's a global namespace that's used if the name isn't in the local namespace.Each variable name is checked in the local namespace (the body of the function, the module, etc.), and then checked in the global ... Read More

This article explains what the Python code expression if __name__ == '__main__' means. A Python programme uses the condition if __name__ == '__main__' to only run the code inside the if statement when the program is run directly by the Python interpreter. The code inside the if statement is not executed when the file's code is imported as a module. What is __main__? The word "__name__" denotes a unique variable in Python. Python has a large number of special variables that begin and end with double underscores. They are referred to as dunder to keep it brief (from Double Underscores). ... Read More

In Python, a namespace package allows you to spread Python code among several projects. This is useful when you want to release related libraries as separate downloads. For example, with the directories Package-1 and Package-2 in PYTHONPATH, Package-1/namespace/__init__.py Package-1/namespace/module1/__init__.py Package-2/namespace/__init__.py Package-2/namespace/module2/__init__.py the end-user can import namespace.module1 and import namespace.module2.On Python 3.3, you don't have to do anything, just don't put any __init__.py in your namespace package directories and it will just work. This is because Python 3.3 introduces implicit namespace packages.On older versions, there's a standard module, called pkgutil, with which you can 'append' modules to a given namespace. You ... Read More

You can use pip to install packages at runtime and importlib.import_module(moduleName) to import module by using its name as a string. For example,import pip import importlib def import_with_auto_install(package):     try:         return importlib.import_module(package)     except ImportError:         pip.main(['install', package])     return importlib.import_module(package) # Example if __name__ == '__main__':     scrapy = import_with_auto_install('scrapy')     print(scrapy)The above script installs the scrapy module and imports it when installation of the module completes.

Easy Install is a python module that is bundled with setuptools (easy_install) that allows you to download, compile, install, and manage Python packages automatically. It was included in setuptools in 2004 and is now deprecated. It was remarkable at the time for automatically installing dependencies and installing packages from PyPI using requirement specifiers. Pip was released later in 2008 as a replacement for easy install, albeit it was still primarily based on setuptools components. Installing Python modules should be done with pip rather than easy install. You can use easy_install to install pip if you have it. The following line ... Read More