Question

What is the standard practice in Python when I have a command-line application taking one argument which is

URL to a web page

or

path to a HTML file somewhere on disk

(only one)

is sufficient the code?

if "http://" in sys.argv[1]:
  print "URL"
else:
  print "path to file"

Answer 1

Depends on what the program must do. If it just prints whether it got a URL, sys.argv[1].startswith('http://') might do. If you must actually use the URL for something useful, do

from urllib2 import urlopen

try:
    f = urlopen(sys.argv[1])
except ValueError:  # invalid URL
    f = open(sys.argv[1])