How to read/process command line arguments?
Just going around evangelizing for argparse which is better for these reasons.. essentially:
(copied from the link)
argparse module can handle positional and optional arguments, while optparse can handle only optional arguments
argparse isn’t dogmatic about what your command line interface should look like - options like -file or /file are supported, as are required options. Optparse refuses to support these features, preferring purity over practicality
argparse produces more informative usage messages, including command-line usage determined from your arguments, and help messages for both positional and optional arguments. The optparse module requires you to write your own usage string, and has no way to display help for positional arguments.
argparse supports action that consume a variable number of command-line args, while optparse requires that the exact number of arguments (e.g. 1, 2, or 3) be known in advance
argparse supports parsers that dispatch to sub-commands, while optparse requires setting
allow_interspersed_args
and doing the parser dispatch manually
And my personal favorite:
- argparse allows the type and
action parameters to
add_argument()
to be specified with simple callables, while optparse requires hacking class attributes likeSTORE_ACTIONS
orCHECK_METHODS
to get proper argument checking
The canonical solution in the standard library is argparse
(docs):
Here is an example:
from argparse import ArgumentParser
parser = ArgumentParser()
parser.add_argument("-f", "--file", dest="filename",
help="write report to FILE", metavar="FILE")
parser.add_argument("-q", "--quiet",
action="store_false", dest="verbose", default=True,
help="don't print status messages to stdout")
args = parser.parse_args()
argparse
supports (among other things):
- Multiple options in any order.
- Short and long options.
- Default values.
- Generation of a usage help message.
import sys
print("\n".join(sys.argv))
sys.argv
is a list that contains all the arguments passed to the script on the command line. sys.argv[0]
is the script name.
Basically,
import sys
print(sys.argv[1:])