I am trying to run one python script (Main_Script) which is supposed to get argparse flag and this script at the same time calls another script(Sub_Script) which is also supposed to get the flag to input. And when I call Main_Script I get an error which says that I can't use the flag because it is not defined in the script but it is actually defined. The error notification makes me use the flag from subscript instead.
MAIN_SCRIPT
parser = argparse.ArgumentParser(add_help=True)
parser.add_argument('-p', '--print_positive_results', action='store_true')
args = parser.parse_args()
PRINT_POSITIVE = args.print_positive_results
#I then use rhi global variable PRINT_POSITIVE
SUB_SCRIPT
import argparse
parser = argparse.ArgumentParser(add_help=True)
parser.add_argument('-d', '--debug', action='store_true')
args = parser.parse_args()
And when I call python MAIN_SCRIPT.py -p I get this
usage: test_grammar.py [-h] [-d]
test_grammar.py: error: unrecognized arguments: -p
DEBUG = False
if (args.debug ):
DEBUG = True
Seems like the command line args from the main script are passed through to the sub script.
You could try to (and probably should) wrap the argparse stuff into:
if __name__ == '__main__':
<argparse stuff>
With this the code is only called when the script is called from the command line. The real code could be outsourced into a function. This way you can use the script from command line with argparse and only import the function from the script if you call it from another script:
Main script:
import argparse
import subscript
if __name__ == '__main__':
parser = argparse.ArgumentParser(add_help=True)
parser.add_argument('-p', '--print_positive_results', action='store_true')
args = parser.parse_args()
...
subscript.your_function(<whatever your args are>)
...
Sub script:
import argparse
def your_function(<your args>):
<your code>
if __name__ == '__main__':
parser = argparse.ArgumentParser(add_help=True)
parser.add_argument('-d', '--debug', action='store_true')
args = parser.parse_args()
your_function(<whatever your args are>)
...
Related
Argparse doesn't seem to check for entire string of option to assign the value. Is this a bug or intended one? What are the use cases for this if this is intended?
Run the following program using python3 test.py -test "testing"
import argparse
if __name__ == '__main__':
parser = argparse.ArgumentParser()
parser.add_argument('-testurl', dest='testurl')
args = parser.parse_args()
print(args)
Output is
Namespace(testurl='testing')
We can use double dash (--) in options and make allow_abbrev=False in parser to force the exact argument to be parsed [reference: argument parser documentation]:
import argparse
if __name__ == '__main__':
parser = argparse.ArgumentParser(allow_abbrev=False)
parser.add_argument('--testurl', dest='testurl')
args = parser.parse_args()
print(args)
Output:
> python3 df_reg.py --test "testing"
usage: df_reg.py [-h] [--testurl TESTURL]
df_reg.py: error: unrecognized arguments: --test testing
> python3 df_reg.py --testurl "testing"
Namespace(testurl='testing')
References:
Argument parser documentation
I am using the argparse library but for whatever reason I'm having difficult printing the -h argument. Here is the entire source I have:
# df.py
import argparse
parser = argparse.ArgumentParser(description='Dedupe assets in our library.')
parser.add_argument('--masters', nargs='?', default=None, type=int, help='Enter one or more ids.')
if __name__ == '__main__':
print ('hi')
I was under the impression that entering in the --h flag via:
$ python df.py --help
Would automatically print the help stuff for the file using argparse but I seem to be making false assumptions. It seems like I also have to add in something like this into my code?
if '--help' in sys.argv: print (parser.parse_args(['-h']))
What is the 'proper' way to print out the help args when using the argparse library?
You forgot to actually parse the arguments; if you put parser.parse_args() in after defining the parser, it would respond to -h/--help. Typically, you'd do something like:
args = parser.parse_args()
so that the args object can be used to access the parsed argument data.
I'll also note that the argument parsing should almost certainly be controlled by the if __name__ == '__main__': guard; if you're not being invoked as the main script, parsing the command line is unusual, to say the least. Idiomatic code would look something like:
# df.py
def main():
import argparse # Could be moved to top level, but given it's only used
# in main, it's not a terrible idea to import in main
parser = argparse.ArgumentParser(description='Dedupe assets in our library.')
parser.add_argument('--masters', nargs='?', type=int, help='Enter one or more ids.')
args = parser.parse_args()
print ('hi')
# Do something with args.masters or whatever
if __name__ == '__main__':
main()
I am passing a single, positional argument string called FILE, but when no arguments are passed, I want it to print a usage statement.
Every time I write './files.py' in my command-line with no arguments after it, my code does nothing. What am I doing wrong?
import argparse
import re
#--------------------------------------------------
def get_args():
"""get arguments"""
parser = argparse.ArgumentParser(
description='Create Python script',
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('FILE', help='Pass a file', type=str)
return parser.parse_args()
#--------------------------------------------------
def main():
"""main"""
args = get_args()
FILE = args.FILE.IGNORECASE()
if len(args) != 1:
print("Usage: files.py {}".format(FILE))
sys.exit(1)
# --------------------------------------------------
if __name__ == '__main__':
main()
Expected outcome:
$ ./files.py
Usage: files.py FILE
What I am getting:
$./files.py
$
You never run main...
import argparse
import re
#--------------------------------------------------
def get_args():
"""get arguments"""
parser = argparse.ArgumentParser(
description='Create Python script',
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('FILE', help='Pass a file', type=str)
return parser.parse_args()
#--------------------------------------------------
def main():
"""main"""
args = get_args()
FILE = args.FILE.IGNORECASE()
if len(args) != 1:
print("Usage: files.py {}".format(FILE))
sys.exit(1)
main()
You need to define the entry point of your code. If you want to call this as you are describing (./files.py) you need to define the main entry point like this:
if __name__ == "__main__":
"""main"""
args = get_args()
FILE = args.FILE.IGNORECASE()
if len(args) != 1:
print("Usage: files.py {}".format(FILE))
sys.exit(1)
You have to tell your operating system that the script must be executed by Python. Add a shebang as the first line of your script:
#!/usr/bin/env python3
import argparse
...
Otherwise, you have to explicitly execute the script with Python:
python3 ./files.py
You must call your main function. A good place is at the end of the script, guarded to be run on execution only:
if __name__ == '__main__': # do not run on import
main()
This gives the desired output:
$ python3 so_script.py
usage: so_script.py [-h] FILE
so_script.py: error: the following arguments are required: FILE
Note that argparse already creates the usage and help messages for you. There is no need to create them yourself. In fact, argparse will end your script before your own usage information is run.
If you do not want to have the -h switch, pass add_help=False when creating the argument parser.
parser = argparse.ArgumentParser(
description='Create Python script',
formatter_class=argparse.ArgumentDefaultsHelpFormatter,
add_help=False,
)
This is probably a silly question, but I have a python script that current takes in a bunch of arguments using argparser and I would like to load this script as a module in another python script, which is fine. But I am not sure how to call the module as no function is defined; can I still call it the same way I do if I was just invoking it from cmd?
Here is the child script:
import argparse as ap
from subprocess import Popen, PIPE
parser = ap.ArgumentParser(
description='Gathers parameters.')
parser.add_argument('-f', metavar='--file', type=ap.FileType('r'), action='store', dest='file',
required=True, help='Path to json parameter file')
parser.add_argument('-t', metavar='--type', type=str, action='store', dest='type',
required=True, help='Type of parameter file.')
parser.add_argument('-g', metavar='--group', type=str, action='store', dest='group',
required=False, help='Group to apply parameters to')
# Gather the provided arguments as an array.
args = parser.parse_args()
... Do stuff in the script
and here is the parent script that I want to invoke the child script from; it also uses arg parser and does some other logic
from configuration import parameterscript as paramscript
# Can I do something like this?
paramscript('parameters/test.params.json', test)
Inside the configuration directory, I also created an init.py file that is empty.
The first argument to parse_args is a list of arguments. By default it's None which means use sys.argv. So you can arrange your script like this:
import argparse as ap
def main(raw_args=None):
parser = ap.ArgumentParser(
description='Gathers parameters.')
parser.add_argument('-f', metavar='--file', type=ap.FileType('r'), action='store', dest='file',
required=True, help='Path to json parameter file')
parser.add_argument('-t', metavar='--type', type=str, action='store', dest='type',
required=True, help='Type of parameter file.')
parser.add_argument('-g', metavar='--group', type=str, action='store', dest='group',
required=False, help='Group to apply parameters to')
# Gather the provided arguments as an array.
args = parser.parse_args(raw_args)
print(vars(args))
# Run with command line arguments precisely when called directly
# (rather than when imported)
if __name__ == '__main__':
main()
And then elsewhere:
from first_module import main
main(['-f', '/etc/hosts', '-t', 'json'])
Output:
{'group': None, 'file': <_io.TextIOWrapper name='/etc/hosts' mode='r' encoding='UTF-8'>, 'type': 'json'}
There may be a simpler and more pythonic way to do this, but here is one possibility using the subprocess module:
Example:
child_script.py
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("-n", "--name", help="your name")
args = parser.parse_args()
print("hello there {}").format(args.name)
Then another Python script can call that script like so:
calling_script.py:
import subprocess
# using Popen may suit better here depending on how you want to deal
# with the output of the child_script.
subprocess.call(["python", "child_script.py", "-n", "Donny"])
Executing the above script would give the following output:
"hello there Donny"
One of the option is to call it as subprocess call like below:
import subprocess
childproc = subprocess.Popen('python childscript.py -file yourjsonfile')
op, oe = childproc.communicate()
print op
I have a python script using argparse. After typing in python script_name.py -h on the command line, it shows help message for another command but the code still works. The script can recognize options defined in it and run well. It looks like the script is packaged by something. I put argparse in a function and everything works well at the beginning. I just can't find out what causes the help message changed.
Here is the code:
#!/usr/bin/env python
import os
import sys
import json
import logging
import argparse
import handlers
HZZ_DIR = os.path.dirname(os.path.abspath(__file__))
ROOT_DIR = os.path.dirname(os.path.dirname(HZZ_DIR))
logger = logging.getLogger('hzz_logger')
logger.setLevel(logging.DEBUG)
console = logging.StreamHandler()
console.setLevel(logging.INFO)
logger.addHandler(console)
def parse_args():
arg_parser = argparse.ArgumentParser()
arg_parser.add_argument('job', choices=['ws','lm','np'],
help="ws: workspace; lm: limit; np: npranking")
arg_parser.add_argument('-a', '--action', nargs=1,
help="for Limit and NPranking: get/plot (limit/pull)")
arg_parser.add_argument('-b', '--blinded', action='store_true',
help="for Limit: true -- do expected only, false -- do observed as well.")
arg_parser.add_argument('-v', '--version', nargs=1, type=int,
help="input version")
arg_parser.add_argument('-t', '--tag', nargs=1,
help='workspace tag')
arg_parser.add_argument('-m', '--mass', nargs='+', type=int,
help='signal mass(es)')
arg_parser.add_argument('-c', '--config', nargs=1,
help='configure file')
arg_parser.add_argument('-u', '--update', action='store_true',
help="update default settings")
args = arg_parser.parse_args()
return args
def load_settings(args):
pass
def run_job(settings):
pass
def execute():
args = parse_args()
settings = load_settings(args)
run_job(settings)
if __name__ == '__main__':
execute()
The help message is pasted here, which is actually the help message a command not directly used in this code. The options for this command can also be recognized...
$ python hzz_handler.py -h
Usage: python [-l] [-b] [-n] [-q] [dir] [[file:]data.root] [file1.C ... fileN.C]
Options:
-b : run in batch mode without graphics
-x : exit on exception
-n : do not execute logon and logoff macros as specified in .rootrc
-q : exit after processing command line macro files
-l : do not show splash screen
dir : if dir is a valid directory cd to it before executing
-? : print usage
-h : print usage
--help : print usage
-config : print ./configure options
-memstat : run with memory usage monitoring
Wow, another anti-Pythonic ROOT mystery! Your question and the comments are really helpful. Why did not anybody post the answer with ROOT.PyConfig.IgnoreCommandLineOptions = True?
Here is a primitive work-around:
import argparse
# notice! ROOT takes over argv and prints its own help message when called from command line!
# instead I want the help message for my script
# therefore, check first if you are running from the command line
# and setup the argparser before ROOT cuts in
if __name__ == '__main__':
parser = argparse.ArgumentParser(
formatter_class = argparse.RawDescriptionHelpFormatter,
description = "my script",
epilog = "Example:\n$ python my_script.py -h"
)
parser.add_argument("param", type=str, help="a parameter")
parser.add_argument("-d", "--debug", action='store_true', help="DEBUG level of logging")
args = parser.parse_args()
if args.debug:
logging.basicConfig(level=logging.DEBUG)
else:
logging.basicConfig(level=logging.INFO)
logging.debug("parsed args: %s" % repr(args))
import ROOT
...
if __name__ == '__main__':
<do something with args>
In sort the answer is that always calls import ROOT after the argparse. Then ROOT won't take over the argparse and prints the required message that we want.