CODEWITHSUNDEEP
pythonlinuxargumentscommand-line-arguments
tijko
tijko

Reputation: 8312

Using Python's sys.argv to return function results to command line?

I have a file that I've made executable. It has a function in it that I would like to return its results to the command line but, I keep getting NameError messages. To break things down, I'm using LinuxMint Lisa and so far I have:

#! /usr/bin/env python
import mechanize
from BeautifulSoup import BeautifulSoup
import sys

def dictionary(word):
    br = mechanize.Browser()
    response = br.open('http://www.dictionary.reference.com')
    br.select_form(nr=0)
    br.form['q'] = word
    br.submit()
    definition = BeautifulSoup(br.response().read())
    trans = definition.findAll('td',{'class':'td3n2'})
    fin = [i.text for i in trans]
    query = {}
    for i in fin:
        query[fin.index(i)] = i
    return query

print dictionary(sys.argv)

Then I chmod from my terminal:

sudo chmod +x this_file.py

When I call this file from the command-line, I'll enter:

./this_file.py 'pass'(or any other string argument)

Which will return:

TypeError: Must assign a string

So I know I'm obviously not using sys.argv correctly but, I have a feeling like I'm mucking something else up when attempting to return this functions results to the command-line.

Upvotes: 3

Views: 2054

Answers (5)

adpeace
adpeace

Reputation: 158

The problem with the question as currently posted is that sys.argv is a list, not a string, so when you set the form entry 'q' you are setting it to a list of arguments to the program. You could change the program to pass in the first argument:

print dictionary(sys.argv[1])

Or call the dictionary functions multiple times:

for i in sys.argv[1:]:
    print dictionary(i)

Note that we don't want to include the program name itself so omit sys.argv[0].

Upvotes: 1

sraok
sraok

Reputation: 615

Shouldn't it have been print dictionary(sys.argv[1]). I guess you want to search the commandline argument in the dictionary.com

Upvotes: 1

Levon
Levon

Reputation: 143082

Ok, I might as well post this as my answer instead of just a comment:

In

print dictionary(agrv)

argv is misspelled.

It should be 

print dictionary(sys.argv)

Also, use sys.argv, argv by itself won't suffice

Upvotes: 3

Daniel Roseman
Daniel Roseman

Reputation: 599748

You don't make it clear what you mean by 'returning' results to the command line. If you just want to print the results, you can do print.

But the error message you're getting has nothing to do with that. It's caused by two things: one, you've put agrv instead of argv. And second, you've imported sys, so you need to reference sys.argv not just argv.

Upvotes: -1

Antimony
Antimony

Reputation: 39451

argv is an attribute of the sys module

Use either

sys.argv

or do

from sys import argv

Upvotes: 2

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