Is Python a

Alternatively, you can fetch (really, copy) names out of a module with from statements:% python # Start Python>>> from myfile import title # Run file; copy its names>>> print title # Use name directly: no need to qualifyThe Meaning of LifeAs you’ll see in more detail later, from is just like an import, with an extra assignmentto names in the importing component. Technically, from copies a module’s attributes,such that they become simple variables in the recipient—thus, you can simply refer tothe imported string this time as title (a variable) instead of myfile.title (anattribute reference). *Whether you use import or from to invoke an import operation, the statements in themodule file myfile.py are executed, and the importing component (here, the interactiveprompt) gains access to names assigned at the top level of the file. There’s onlyone such name in this simple example—the variable title, assigned to a string—butthe concept will be more useful when you start defining objects such as functionsand classes in your modules. Such objects become reusable software componentsthat can be accessed by name from one or more client modules.In practice, module files usually define more than one name to be used in and outsidethe files. Here’s an example that defines three:a = 'dead'b = 'parrot'c = 'sketch'print a, b, c# Define three attributes# Exported to other files# Also used in this fileThis file, threenames.py, assigns three variables, and so generates three attributes forthe outside world. It also uses its own three variables in a print statement, as we seewhen we run this as a top-level file:% python threenames.pydead parrot sketchAll of this file’s code runs as usual the first time it is imported elsewhere (by either animport or from). Clients of this file that use import get a module with attributes, whileclients that use from get copies of the file’s names:% python>>> import threenames # Grab the whole moduledead parrot sketch>>>>>> threenames.b, threenames.c('parrot', 'sketch')>>>* Notice that import and from both list the name of the module file as simply myfile without its .py suffix. Asyou’ll learn in Part V, when Python looks for the actual file, it knows to include the suffix in its search procedure.Again, you must remember to include the suffix in system shell command lines, but not in importstatements.48 | Chapter 3: How You Run Programs