I highly recommend argparse which comes with Python 2.7 and later.. The argparse module reduces boiler plate code and makes your code more robust, because the module handles all standard use cases (including subcommands), generates the help and usage for you, checks and sanitize the user input - all stuff you have to worry about when you are using sys.argv approach.

The goals here are to be terse, each argument parsed by a single line, the args line up for readability, the code is simple and doesn't depend on any special modules (only os + sys), warns about missing or unknown arguments gracefully, use a simple for/range() loop, and works across python 2.x and 3.x

In Python, how can we find out the command line arguments that were provided for a script, and process them? Related background reading: What does "sys.argv[1]" mean? (What is sys.argv, and where does it come from?) .

sys.arg is a list of command line parameters. You need to actually pass command line parameters to the script to populate this list. Do this either in your IDE's project settings or by running like this on the command line: python script.py first second third Note that the first argument is always the script's name (python script.py in this case).

Apr 4, 2014 · The argparse module makes it easy to write user-friendly command-line interfaces. The program defines what arguments it requires, and argparse will figure out how to parse those out of sys.argv. The argparse module also automatically generates help and usage messages and issues errors when users give the program invalid arguments.

@Kevin Bell, the test for __name__ == "__main__" will return true if the script is run from the command line, rather than imported in the python interpreter, or another script. The design is up to you - if you program is self contained in that single script, then you can just add the __name__ == "__main__" test to allow it to be launched from ...

Apr 24, 2010 · python script.py 001 002 245 568 python script.py some unexpected argument python script.py 0001 python script.py 02 ...first one - because of more than one "numeric" argument; second - because of... well, unexpected arguments; third and fourth - because of non-3-digits arguments.

In command line I am able to pass arguments to a python file as: python script.py arg1 arg2 I can than retrieve arg1 and arg2 within script.py as: import sys arg1 = sys.argv[1] arg2 = sys.argv[2] However, I would like to send keyword arguments to a python script, and retrieve them as a dictionary: python script.py key1=value1 key2=value2

Aug 31, 2011 · For a posixy feel, you shouldn't only provide the standard command line options, both short and long, but also, if possible, adhere to reading from the standard input (or the command line) and writing to the standard output, and only overriding the output with an option (like -o/--output). That's what one expects of most GNU command line tools.

Parses command line options and parameter list. args is the argument list to be parsed, without the leading reference to the running program. Typically, this means sys.argv[1:]. options is the string of option letters that the script wants to recognize, with options that require an argument followed by a colon (':'; i.e., the same format that ...