python sys.argv 默认值

sys.argv其实就是个list，如果为空，可以argv=[]

args = sys.argv[1:]
args.append("pascal")
args.append("pascal_path")

如果为None：

#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys
def main(argv):
if argv == None:
argv=[]
argv.append("asdfsdf")
print(argv)
print('world~!')
else:
argv.append("asdfsdf")
print(argv)
print('hello')
if __name__ == '__main__':
main(None)

如果不为None：

#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys
def main(argv):
if argv == None:
print('world~!')
else:
argv.append("asdfsdf")
print(argv)
print('hello')
if __name__ == '__main__':
main(sys.argv)

sys.argv其实就是个list，如果为空，可以argv=[]

args = sys.argv[1:]
args.append("pascal")
args.append("pascal_path")

如果为None：

#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys
def main(argv):
if argv == None:
argv=[]
argv.append("asdfsdf")
print(argv)
print('world~!')
else:
argv.append("asdfsdf")
print(argv)
print('hello')
if __name__ == '__main__':
main(None)

如果不为None：

#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys
def main(argv):
if argv == None:
print('world~!')
else:
argv.append("asdfsdf")
print(argv)
print('hello')
if __name__ == '__main__':
main(sys.argv)

from optparse import OptionParser

usage = "usage: %prog [options] arg1 arg2"
parser = OptionParser(usage=usage)  # 创建OptionParser对象

parser.add_option("-v", "--verbose",  # add_option增加选项
action="store_true", dest="verbose", default=True,
help="make lots of noise [default]")
parser.add_option("-q", "--quiet",
action="store_false", dest="verbose",
help="be vewwy quiet (I'm hunting wabbits)")
parser.add_option("-f", "--filename",
metavar="FILE", help="write output to FILE"),
parser.add_option("-m", "--mode",
default="intermediate",
help="interaction mode: novice, intermediate, "
                       "or expert [default: %default]")

(options, args) = parser.parse_args()  # 解析选项
print(options)