Command line arguments as variable definition in Python

问题

I'm trying to construct a (kind of template/wrapper) script, which is called with some undefined options

> the_script.py --foo=23 --bar=42 --narf=fjoord

which then creates a variable called foo=23, bar=42, narf='fjoord' inside it.

What's the way to do it? I tried with getopt, but it needs a second parameter, so I have to define which options to get and of course, I want to be able to define my variable names via command line. I tried OptionParser too, not sure how to deal with undefined options though.

So is the way manually parsing the sys.argv, or is there maybe a module out there, which does exactly the same thing?

回答1:

This is a relatively simple task with ast.literal_eval and string splitting -- But only if you have a really well defined syntax. (e.g. only 1 of --foo=bar or --foo bar is allowed).

import argparse
import ast

parser = argparse.ArgumentParser() #allow the creation of known arguments ...

namespace,unparsed = parser.parse_known_args()

def parse_arg(arg):
    k,v = arg.split('=',1)
    try:
        v = ast.literal_eval(v) #evaluate the string as if it was a python literal
    except ValueError:          #if we fail, then we keep it as a string
        pass

    return k.lstrip('-'),v

d = dict(parse_arg(arg) for arg in unparsed)
print(d)

I've put the key-value pairs in a dictionary. If you really want them as global variables, you could do globals().update(d) -- But I would seriously advise against that.

回答2:

Use this. Maybe you need some string '' brackets some where...

>>python yourfunc.py foo=4 abc=5

import sys 
list=sys.argv[1:]
for i in list:
   exec(i)

来源：https://stackoverflow.com/questions/17086594/command-line-arguments-as-variable-definition-in-python

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python

command-line-arguments