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Closed 10 years ago.
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How can I pass command-line arguments in IronPython?
I am new to ironpython and sharpdevelop and I am trying to run the following code,
from sys import argv
script, first, second, third = argv
print "The script is called:", script
print "Your first variable is:", first
print "Your second variable is:", second
print "Your third variable is:", third
How do I pass the arguments to the command line ?
In SharpDevelop you
right-click on the python project
choose Properties in the context-menu
choose the Debug-tab
append your arguments in the Command line arguments field
Does this article help you at all?
You need to set the values of sys.argv.
engine.Sys.argv = List.Make(args);
Related
This question already has answers here:
How to read/process command line arguments?
(22 answers)
Closed 1 year ago.
Here an example
program1.py
n=input("enter any data")
print(n)
Execute it
python3 program1.py "Hello World!"
output:
Hello World!
Here the user don't type any value .The program took value given in commandline as #input() value
So how can I achieve it?
The command line arguments are delivered in the sys.argv list. The first entry is the name of the script itself (program1.py in your example.
import sys
print( sys.argv[1] )
If you pass multiple words, they'll come in the rest of the list. So, for example:
import sys
print( ''.join(sys.argv[1:])
Output:
$ python program1.py this is a test
this is a test
$
I am not getting desired output of this program?
from sys import argv
script, first, second, third = argv
print ("The script is called:", script)
print ("Your first variable is:", first)
print ("Your second variable is:", second)
print ("Your third variable is:", third)
How to use cmd to pass these arguments?
You call it like
python program.py a1 b2 c3
and it outputs
The script is called: /home/sophia/program.py
Your first variable is: a1
Your second variable is: b2
Your third variable is: c3
sys.argv contains list of strings, each corresponding to a command line parameter. First one is always the filename of the script; others are the optional parameters, ordered exactly as they were typed in a shell.
Note that the code you provided works correctly only when you pass exactly three parameters due to the tuple unpacking.
See the docs for sys.argv and also check out argparse module documentation if you are going to write a program handling lots of arguments.
This question already has answers here:
Python Value Error: not enough values to unpack
(4 answers)
Closed 2 years ago.
I'm using Learning Python the Hard Way. In the process of my learning I came across this error. Though I have been trying to debug since yesterday, I couldn't.
This is my code:
import sys
from sys import argv
script, first, second = argv
print('the script is called:', script)
print('the first variable is:', first)
print('the second vriable is:', second)
print('the third variable is:', third)
The error you're getting means you're trying to deconstruct an iterable (list, tuple) into more values than there are in the actual list. If you were to run
print(argv, len(argv))
You might see that you don't have three variables in argv.
argv shows the parameters you provided while running a script. So for example, if I ran:
python test_args.py
I would only receive: ['test_args.py'] as my argv variable. If I tried providing more parameters, like:
python test_args.py a b
Then my argv would look like: ['test_args.py', 'a', 'b']. Your code is completely dependent on how many parameters are passed when you are running it, so mess around with that as well to get a better sense of what is going on.
I suppose that you are executing the script in this format
python script.py 10 20
The problem is that you are using an extra variable third which is not initialized.
If you really want 3 arguments, then you have to pass three values at execution time as follows.
python script.py 10 20 30
Then change the code as follows.
from sys import argv
script, first, second, third = argv
print('the script is called:', script)
print('the first variable is:', first)
print('the second vriable is:', second)
print('the third variable is:', third)
Thank you
This question already has answers here:
What does "sys.argv[1]" mean? (What is sys.argv, and where does it come from?)
(9 answers)
Closed 7 months ago.
I am working my way through "Learning Python the Hard Way". I am totally stumped on "Exercise 13: parameters, unpacking, variables". I'm using Sublime Text 3 in a Windows 7 environment.
Here is my code:
from sys import argv
script, first, second = argv
print ("The script is called:", script)
print ("Your first variable:", first)
print ("Your second variable:", second)
Now my questions:
Do I put this in the scripts folder and then reference this from another .py file something like...
c:\scripts\python\ex11.py one_thing second_thing another_thing
...or do I use a file in my scripts folder to reference my file in another folder that is holding my .py files?
What is the syntax to point to another file in another folder?
It helps to determine what the arguments vector, or argv actually does. It's reading in what you pass in to it from the command line.
So, this means that this command should work (provided Python is in your path, and you can just execute the file in this manner):
C:\scripts\python\ex11.py one_thing second_thing another_thing
Note that you'll only see one_thing and second_thing come across; the first value is the name of the script.
When using the command line to run programs, arguments can be specified to get the program to run in different ways.
In this example, you will need to open up powershell, run cd c:\scripts\python\, and then python ex11.py one_thing second_thing another_thing
I'm running the code below in Spyder.
I have typed it in a py file and simply hit the run button.
When I try to run it I get the error:
ValueError: need more than 1 value to unpack
As shown here you are meant to give the inputs for the argv variable before running the program but I don't know how to do this is spyder?
http://learnpythonthehardway.org/book/ex13.html
from sys import argv
script, first, second, third = argv
print "The script is called:", script
print "The first variable is:", first
print "The second variable is:", second
print "Your third variable is:", third
To pass argv to a script in Spyder, you need to go the menu entry
Run > Configuration per file
or press the Ctrl+F6 key, then look for the option called
Command line options
on the dialog that appears after that, and finally enter the command line arguments you want to pass to the script, which in this case could be
one two three
In addition to configuring in the Run->Configure as explained in other answers,
you can use "runfile" directly from the console.
Run the following:
runfile('ex13.py', args='first second third')
In Spyder, go Run > Configure and define your argv values as showing in following diagram and to run the script just press F6
Read the FAQ at the bottom of the page, it specifically mentions this error.
Common Student Questions
Q. When I run it I get ValueError: need more than 1 value to unpack.
Remember that an important skill is paying attention to details. If you look at the What You Should See section you see that I run the script with parameters on the command line. You should replicate how I ran it exactly.
Make sure you run the command:
$ python ex13.py first 2nd 3rd
>> The script is called: ex13.py
>> Your first variable is: first
>> Your second variable is: 2nd
>> Your third variable is: 3rd
You can ensure that the arguments are supplied.
if __name__ == '__main__':
if len(argv) == 4:
script, first, second, third = argv
print 'The script is called:', script
print 'Your first variable is:', first
print 'Your second variable is:', second
print 'Your third variable is:', third
else:
print 'You forgot the args...'