Python Four week five lessons

One, logging module

Logging modules are typically used to print log information, log level critical > Error > Warning > Info > Debug > NotSet, lower log level output more information

Logging usage 1: Print log information directly to the screen and print only log information above warning level by default

 #!/usr/bin/python Import Logginglogging.debug (   this is debug message    ) Logging.info (  "  This is info message   " ) logging.warning (   " this is warning message   '   ' Logging.error (  " this is error message   ) 
  

1is an error message 

Logging Usage 2: Save log information to a file by using the Basicconfig () function

#!/usr/bin/pythonimport logginglogging.basicconfig ( level=logging. DEBUG, Format='% (asctime) s% (filename) s[line:% (lineno) d]% (levelname) s% (message) s', # Set the output format of the log information datefmt='%a,%d%b%Y%h:%m:%s', # Set the time format for log information filename='Myapp.log', # Set log information to which file to save FileMode='W') # Specifies the open mode of the log file Logging.debug ('This is debug message') Logging.info ('This is info message') logging.warning ('This is warning message')

[[email protected] ~]# python1. py [[email protected]~]# cat Myapp.log Fri,TenNov .  +: A: One 1. Py[line:Ten] DEBUG This isDebug Messagefri,TenNov .  +: A: One 1. Py[line: One] INFO This isInfo Messagefri,TenNov .  +: A: One 1. Py[line: A] WARNING This isWarning message

Output format:

% (Levelno) S: Print the value of the log level
% (levelname) S: Print log level name
% (pathname) s: Prints the path of the currently executing program, which is actually sys.argv[0]
% (filename) s: Prints the current name of the executing program
% (funcName) s: Print the current function of the log
% (Lineno) d: Print the current line number of the log
% (asctime) s: Time to print logs
% (thread) d: Print thread ID
% (threadname) s: Print thread name
% (process) d: Print process ID
% (message) s: Print log information

Second, OS module

Os.listdir (): Used to print a list of files in a specified directory, such as Os.listdir ('/tmp/')

Os.path.isdir (): Used to determine if the directory exists, if present returns True if there is no return False

Os.path.isfile (): Used to determine if the file exists, if present returns True if there is no return False

Os.path.join (): Used to connect two parameters, usually used to connect the file name, such as Os.path.join (' etc ', ' passwd ') returns the result as '/etc/passwd '

Os.path.split (): Used to separate directories and files, such as Os.path.split ('/etc/passwd ') returns the result as ('/etc ', ' passwd ')

Os.path.exists (): Used to determine if a variable, file, etc. exists, returns True if there is no return False if there is no

Os.path.getsize (): Used to get the size of the file, by default in K, such as Os.path.getsize ('/tmp/1.txt ')

Os.path.basename (): Returns only the file name part, such as Os.path.basename ('/etc/passwd ') returns the result as ' passwd '

Os.path.dirname (): Returns only the directory part, such as Os.path.basename ('/etc/passwd '), returns the result as '/etc '

OS.GETCWD (): Used to get the current directory

Os.chdir (): Used to change the working directory, equivalent to a CD command, such as Os.chdir ('/tmp ') equivalent to Cd/tmp

Os.mkdir (): Used to create the directory, equivalent to the mkdir command, such as Os.mkdir ('/tmp/test ') equivalent to Mkdir/tmp/test

Os.mkdirs (): Used to recursively create a directory, such as Os.mkdirs ('/tmp/a/b/c ') equivalent to Mkdir-p/tmp/a/b/c

Os.remove (): Used to delete the specified file, such as Os.remove ('/tmp/1.txt ')

Os.rmdir (): Used to delete the specified directory, such as Os.rmdir ('/tmp/test ')

Os.walk (): For files in the iteration directory, detailed usage

Os.name: Judging system platform, Windows system returns ' NT ', Linux system returns ' POSIX '

Os.system (): Used to execute shell commands, such as Os.system (' ls/tmp '), detailed usage

Os.popen (): Used to execute shell commands, but only return standard output, detailed usage

Os.popen2 (): Used to execute shell commands, return standard input and standard output, detailed usage

Os.popen3 (): Used to execute shell commands, return standard input, standard output, standard error output, detailed usage

Three, commands module

Commands modules are typically used to execute some shell commands

Commands.getoutput (): Used to execute shell commands, such as Commands.getoutput (' ls/tmp/')

Commands.getstatusoutput (): Used to execute shell commands and return status codes after command execution

Four, sys module

Sys.exit (): Used to exit the entire script

Sys.stdin.read (): For receiving standard input, waiting for keyboard input after execution

Sys.stdout.write (): Used to output standard output, such as Sys.stdout.write (' Hello ') will print out Hello, default non-newline character

Sys.stderr.write (): Used to output standard error output, such as Sys.stderr.write (' Hello ') will print out Hello, default non-newline character

SYS.ARGV: Used to receive command-line arguments, consistent with $n usage in shell scripts, such as Sys.argv[0 ] equivalent to $ (that is, file name), Sys.argv[1] equivalent to $ (That is, the first parameter), Sys.argv[2 ] is equivalent to $ (the second argument), and so on

Python Four week five lessons