its320 chapter 11 modules
import structure
Construct 11.3.1: Importing specific names from a module. from module_name import name1, name2, ...
built in module
a module that come pre-installed with python, some are sys, time, and math.
from keyword
a programmer can specify names to import from a module and use from
hashlib
a python standard library module that contains a number of algorithms for creating a secure hash
reload()
function can be used to reload and re-execute the changed module. This is used becuase when you import a module it only runs once and if it needs to be changed just use the reload() function
import
importing a module means to execute the code contained by the module and make the definitions within that module available for use by importing the program
packages
instead of only using import for a single module, packages gives access to all of the modules. used for large projects.
__name__
is a global string variable automatically added to every module that contains the name of the module example my_funcs__name__ would have the value "my_funcs" this is always set to __main__
module object
is if the module has not been loaded in the sys.module then a new module is create. It is a namespace that contains definitions from the module
sys.path
is the list of directories
__main__
is to differentiate the script from imported modules example if __name__ == "__main__": if this is true then the file is being executed as a script and the branch is taken.
script
is where a programmer writes python code and passes the code to the file into an input to the interpreter
environmental variable
like a variable in python except hat it is stored in the computer's operating system and be accessed by every program running on the computer
PYTHONPATH
place in the module this is the environmental variable
__file__
special name contains the path to a module in the computer file system
hash
text message. a secure hash correlates exactly to a single series of characters
__init__.py
the __init__.py is used to indicate that a directory is a package. the __init__.py is usually empty but may contain code to initialize the package when improted
access items in namespace
use the dot method ex: Complete the statement to call the draw_square function from the shapes module, passing an argument of 3. shapes.draw_square(3) shapes.draw_square(3) Dot notation is used to access items in the namespace of the imported module.
module
when a programmer writes the same function over and over it is easier to use a module, which is a file containing python doce that can be imported and used by scripts other modules or the interactive interpreter.