argparse

• argparse

When there is a Python script called run.py , we can run the file at the command prompt as follows.

$ ./run.py

 

If you want your Python script to work differently depending on the options, you'll need to get these arguments through the command line such as below.

$ ./run.py -d 1 -f

 

• It must parse the arguments(ex, '-d', '-f') of the command line entered by the user,
• and then perform appropriate actions according to the argument.
• The module used to parse the arguments of the command line is argparse.

---

Add the arguments to parse via the add_argument method.

These are you should be aware of.

• action="store" : to receive additional options.
• action="store_true" : if you do not receive any additional options and just need the presence/absence of the options.
• dest : Option values entered by the user are stored in the variable specified by the dest arguments.
• required : Indicate whether an argument is required or optional, True or False.
• help : Help message for an argument
• default : Default value used when an argument is not provided, Defaults to None.

---

Example 1.

 

# run.py
import argparse

parser = argparse.ArgumentParser()
parser.add_argument("-d", "--decimal", dest="decimal", action="store") # extra value
parser.add_argument("-f", "--fast", dest="fast", action="store_true") # existence/nonexistence
args = parser.parse_args()

print(args.decimal)
print(args.fast)

 

parse_args() : Save the above(what added via add_argument) in args.

---

# terminal
$ ./run.py -d 1 -f

---

• Parse the -d and -f options entered by the user 
• and save 1 and True (because the -f option exists) to the args object 
• and return.

# result
1          # args.decimal
True       # args.fast

 

 

---

Example 2.

 

parser = argparse.ArgumentParser()
parser.add_argument(dest="width", action="store")
parser.add_argument(dest="height", action="store")
parser.add_argument("--frames", dest="frames", action="store")
parser.add_argument("--qp", dest="qp", action="store")
parser.add_argument("--configure", dest="configure", action="store")

args = parser.parse_args(["64", "56", "--frames", "60", "--qp", "1", "--configure", "AI"])
print(args.width, args.height, args.frames, args.qp, args.configure)

 

https://wikidocs.net/73785

https://docs.python.org/3/library/argparse.html