How to use sys. argv []

Sysargv [] is used to obtain command line parameters. sysargv [0] indicates the file path of the code. for example, if you input pythontestpy-help in the CMD command line, sysargv [0] indicates testpy. Sysstartswith () is used to determine the beginning of an object, for example, in sys. argv [] is used to obtain command line parameters, sys. argv [0] indicates the path of the code file. for example, enter "python test. py-help ", then sys. argv [0] indicates "test. py ".

Sys. startswith () is used to determine the starting point of an object. for example, if you enter 'ABC'. startswith ('AB') in the python command line, True is returned.

For the following examples:

#! /Usr/local/bin/env pythonimport sysdef readfile (filename): '''print a file to the standard output. '''f = file (filename) while True: line = f. readline () if len (line) = 0: break print line, f. close () print "sys. argv [0] --------- ", sys. argv [0] print "sys. argv [1] --------- ", sys. argv [1] print "sys. argv [2] --------- ", sys. argv [2] # Script starts from hereif len (sys. argv) <2: print 'no action specified. 'sys. exit () if sys. argv [1]. startswith ('--'): option = sys. argv [1] [2:] # fetch sys. argv [1] but without the first two characters if option = 'version': print 'version 1.2 'elif option = 'help ': print ''' "This program prints files to the standard output. any number of files can be specified. options include: -- version: Prints the version number -- help: Display this help ''' else: print 'unknown option. 'sys. exit () else: for filename in sys. argv [1:]: readfile (filename) execution result: # python test. py -- version helpsys. argv [0] --------- test. pysys. argv [1] --------- -- versionsys. argv [2] --------- helpVersion 1.2

Note: sys. argv [1] [2:] indicates to intercept the second parameter from the third character to the end. In this example, the result is: version.

The above describes how to use sys. argv []. For more information, see other related articles in the first PHP community!