Python3.2 Official document Translation--Overview of the standard library (i)

7.1Operating System Interface

The OS module provides many of the main functions that interact with the operating system.

>>> Import OS

>>> os.getcwd () # Return the current working directory

'c:\\python31'

>>> os.chdir ('/server/accesslogs') # Change current working directory

>>> Os.system ('mkdir today') # Run the command mkdir in the system shell

0

Be sure to replace the FROM OS import * with the import OS method . this will make Os.open () method overrides the built -in Open () function.

Because they operate in very different ways.

The built-in methods of the dir () and help () methods are useful for interacting with large modules such as the OS .

>>> Import OS

>>> dir (OS)

<returns a list of all module functions>

>>> Help (OS)

<returns an extensive manual page created from the module's docstrings>

For daily file and folder management tasks, theshutill module provides a higher-level and user-friendly interface.

>>> Import Shutil

>>> shutil.copyfile ('data.db', 'archive.db' )

>>> shutil.move ('/build/executables', ' InstallDir')

7.2File wildcard characters

The Glob module provides a function used to search for a list of production files from a folder wildcard.

>>> Import Glob

>>> Glob.glob ('*.py')

['primes.py', 'random.py', ' quote.py ' ]

7.3command line number of parameters

Common tool scripts often need to provide command-line parameters. These parameters are saved as a list in the argv property of the sys module . Like what. The output is then obtained by executing python demo.py One, three, on the command line .

>>> Import Sys

>>> Print (SYS.ARGV)

[ " demo.py " ,&NBSP; Span style= "font-family: Arial" > ' one " ,&NBSP; " two " ,&NBSP; " three "

The Getopt module uses the Unix custom Getopt () function to perform sys.argv. in the Argparse The module provides many more powerful and flexible command-line operations.

7.4Error output redirection and program termination

The Sys module also contains many properties such as stdin,stdout , and stderr. The subsequent property pass is often used to throw warnings or error messages, and error messages can be seen when stdout redirects.

The most straightforward way to terminate a script is to use the sys.exit () method.

>>> sys.stderr.write ('Warning, log file not found starting a new one\n')

Warning, log file not found starting a new one

Python3.2 Official document Translation--Overview of the standard library (i)