sys.argv[]是用來獲取命令列引數的,sys.argv[0]表示程式碼本身檔案路徑;比如在CMD命令列輸入 “python test.py -help”,那麼sys.argv[0]就代表“test.py”。
sys.startswith() 是用來判斷一個物件是以什麼開頭的,比如在python命令列輸入“'abc'.startswith('ab')”就會返回True
以下例項參考:
#!/usr/local/bin/env python import sys def 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 here if 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) 執行結果:# python test.py --version help sys.argv[0]--------- test.py sys.argv[1]--------- --version sys.argv[2]--------- help Version 1.2
注意:sys.argv[1][2:]表示從第二個引數,從第三個字元開始擷取到最後結尾,本例結果為:version