Python error: the following arguments are required - python

I have the Python script that works well when executing it via command line.
What I'm trying to do is to import this script to another python file and run it from there.
The problem is that the initial script requires arguments. They are defined as follows:
#file one.py
def main(*args):
import argparse
parser = argparse.ArgumentParser(description='MyApp')
parser.add_argument('-o','--output',dest='output', help='Output file image', default='output.png')
parser.add_argument('files', metavar='IMAGE', nargs='+', help='Input image file(s)')
a = parser.parse_args()
I imported this script to another file and passed arguments:
#file two.py
import one
one.main('-o file.png', 'image1.png', 'image2.png')
But although I defined input images as arguments, I still got the following error:
usage: two.py [-h] [-o OUTPUT]
IMAGE [IMAGE ...]
two.py: error: the following arguments are required: IMAGE

When calling argparse with arguments not from sys.argv you've got to call it with
parser.parse_args(args)
instead of just
parser.parse_args()

If your MAIN isn't a def / function you can simulate the args being passed in:
if __name__=='__main__':
# Set up command-line arguments
parser = ArgumentParser(description="Simple employee shift roster generator.")
parser.add_argument("constraints_file", type=FileType('r'),
help="Configuration file containing staff constraints.")
parser.add_argument("first_day", type=str,
help="Date of first day of roster (dd/mm/yy)")
parser.add_argument("last_day", type=str,
help="Date of last day of roster (dd/mm/yy)")
#Simulate the args to be expected... <--- SEE HERE!!!
argv = ["",".\constraints.txt", "1/5/13", "1/6/13"]
# Parse arguments
args = parser.parse_args(argv[1:])

Related

Run a script that requires multiple arguments and uses ExitStack

I have a python3 script that requires three arguments: -orig, -corr, -out, where "orig" and "corr" are used to generate "out". "-orig" allows for only one file as argument, while "-corr" allows for multiple files as input. The script uses ExitStack for handling multiple files at the same time.
When I run the script in command line specifying the files for each argument:
python3 myscript.py -orig <orig_file> -cor <cor_file1> [<cor_file2> ...] -out <outputfile>
it works without problem, but I would like to run the script over several "orig" files and the corresponding "corr" files. Any ideas?
This is the start of the script:
with ExitStack() as stack:
in_files = [stack.enter_context(open(i)) for i in [args.orig]+args.cor]
# Process each line of all input files.
for line_id, line in enumerate(zip(*in_files)):
orig_sent = line[0].strip()
cor_sents = line[1:]
And the section corresponding to the arguments:
if __name__ == "__main__":
# Define and parse program input
parser = argparse.ArgumentParser(description="blabla",formatter_class=argparse.RawTextHelpFormatter, usage="%(prog)s [-h] [options] -orig ORIG -cor COR [COR ...] -out OUT")
parser.add_argument("-orig", help="The path to the original text file.", required=True)
parser.add_argument("-cor", help="The paths to >= 1 corrected text files.", nargs="+", default=[], required=True)
parser.add_argument("-out", help="The output filepath.", required=True)
args = parser.parse_args()
# Run the program.
main(args)

Allow unknown arguments using argparse

I have a python script that requires the user to enter two arguments to run it, the arguments could be named anything.
I have also used argparse to allow the users to use a switch '-h' to get instructions of what is required to run the script.
The problem is that now I have used argparse I am getting an error when I pass my two randomly named arguments with the script.
import argparse
parser = argparse.ArgumentParser(add_help=False)
parser.add_argument('-h', '--help', action='help',
help='To run this script please provide two arguments')
parser.parse_args()
currently when I run python test.py arg1 arg2 the error is
error: unrecognized arguments: arg1 arg2
I would like the code to allow the user to run test.py with a -h if required to see the instructions but also allow them to run the script with any two arguments as well.
Resolution with help tag to provide the user with context regarding the arguments required.
parser = argparse.ArgumentParser(add_help=False)
parser.add_argument('-h', '--help', action='help', help='To run this script please provide two arguments: first argument should be your scorm package name, second argument should be your html file name. Note: Any current zipped folder in the run directory with the same scorm package name will be overwritten.')
parser.add_argument('package_name', action="store", help='Please provide your scorm package name as the first argument')
parser.add_argument('html_file_name', action="store", help='Please provide your html file name as the second argument')
parser.parse_args()
Try the following code :-
import argparse
parser = argparse.ArgumentParser(add_help=False)
parser.add_argument('-h', '--help', action='help',
help='To run this script please provide two arguments')
parser.add_argument('arg1')
parser.add_argument('arg2')
args, unknown = parser.parse_known_args()
All your unknown arguments will be parsed in unknown and all known in args.
import argparse
parser = argparse.ArgumentParser(description='sample')
# Add mandatory arguments
parser.add_argument('arg1', action="store")
parser.add_argument('arg2', action="store")
# Parse the arguments
args = parser.parse_args()
# sample usage of args
print (float(args.arg1) + float(args.arg2))
You need to add those arguments to the parser:
parser.add_argument("--arg1", "-a1", dest='arg1', type=str)
parser.add_argument("--arg2","-a2", dest='arg2', type=str)
If those arguments don't have the param required=true, you will be able to call the program without this arguments, so you can run the program with only the -h flag. To run the program with the arguments:
python test.py --arg1 "Argument" --arg2 "Argument"
Then, to have the arguments in variables you have to read them:
args = parser.parse_args()
argument1=args.arg1
argument2=args.arg2

Use argparse to send arguments to function within Python script

I am in the bit of a weird situation where I need a Python function to run from within a script, with the script then called from my main code.
I wanted to use the subprocess module, and know how to use it to pass arguments to a pure script, but the thing is, I need to pass the arguments to the nested Python function within, most of which are optional and have default values.
I thought arparse would help me do this somehow.
Here is an example of what I am trying:
## Some Argparse, which will hopefully help
import argparse
parser = argparse.ArgumentParser()
## All arguments, with only "follow" being required
parser.add_argument('file_name', help='Name of resulting csv file')
parser.add_argument('sub_name', help='Sub-name of resulting csv file')
parser.add_argument('follow', help='Account(s) to follow', required=True)
parser.add_argument('locations', help='Locations')
parser.add_argument('languages', help='Languages')
parser.add_argument('time_limit', help='How long to keep stream open')
args = parser.parse_args()
## Actual Function
def twitter_stream_listener(file_name=None,
sub_name='stream_',
auth = api.auth,
filter_track=None,
follow=None,
locations=None,
languages=None,
time_limit=20):
... function code ...
... more function code ...
...
...
## End of script
If you are passing arguments to functions all you need to do is feed them into the function when you're executing them:
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("-o", "--output_file_name", help="Name of resulting csv file")
parser.add_argument("-s", "--sub_name", default="stream_", help="Sub-name of resulting csv file")
parser.add_argument("-f", "--follow", help="Account(s) to follow", required=True)
parser.add_argument("-loc", "--locations", default=None, help="Locations")
parser.add_argument("-lan", "--languages", default=None, help="Languages")
parser.add_argument("-t", "--time_limit", default=20, help="How long to keep stream open")
options = parser.parse_args()
# then just pass in the arguments when you run the function
twitter_stream_listener(file_name=options.output_file_name,
sub_name=options.sub_name,
auth=api.auth,
filter_track=None,
follow=options.follow,
locations=options.locations,
languages=options.languages,
time_limit=options.time_limit)
# or, pass the arguments into the functions when defining your function
def twitter_stream_listener_with_args(file_name=options.output_file_name,
sub_name=options.sub_name,
auth=api.auth,
filter_track=None,
follow=options.follow,
locations=options.locations,
languages=options.languages,
time_limit=options.time_limit):
# does something
pass
# then run with default parameters
twitter_stream_listener_with_args()
You can specify defaults in the argparse section (if that is what you are trying to achieve):
#!/usr/bin/python
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('--argument', default = 'something', type = str, help = 'not helpful')
parser.add_argument('--arg2', default = None, type = str, help = 'not helpful')
args = parser.parse_args()
def foo(arg , arg2 ):
print(arg)
if not arg2 is None:
print(arg2)
foo(args.argument, args.arg2)
Then calling:
$ ./test.py
something
$ ./test.py --argument='somethingelse'
somethingelse
$ ./test.py --arg2=123
something
123
$ ./test.py --arg2='ipsum' --argument='lorem'
lorem
ipsum
Is this helpful?
You can do it like that:
import argparse
## Actual Function
def twitter_stream_listener(file_name=None,
sub_name='stream_',
auth=api.auth,
filter_track=None,
follow=None,
locations=None,
languages=None,
time_limit=20):
# Your content here
if __name__ == '__main__':
parser = argparse.ArgumentParser()
## All arguments, with only "follow" being required
parser.add_argument('follow', help='Account(s) to follow')
parser.add_argument('--file_name', help='Name of resulting csv file')
parser.add_argument('--sub_name', help='Sub-name of resulting csv file')
parser.add_argument('--locations', help='Locations')
parser.add_argument('--languages', help='Languages')
parser.add_argument('--time_limit', help='How long to keep stream open')
args = parser.parse_args()
twitter_stream_listener(file_name=args.file_name, sub_name=args.sub_name, follow=args.follow,
locations=args.locations, languages=args.languages, time_limit=args.time_limit)
follow will be the only required argument and the rest optional. Optional ones have to be provided with -- at the beginning. You can easily use the module with subprocess if you need it.
Example call using command line:
python -m your_module_name follow_val --file_name sth1 --locations sth2

Creating artificially parsed arguments

My program "program.py" has the form:
if __name__=='__main__':
args = parse_args()
main_function(args)
However, if I import program.py as a module and run program.main_function, how can I pass the parsed arguments structure as an argument to the main_function?
Here is the definition of the parse_args()
def parse_args():
parser=argparse.ArgumentParser()
parser.add_argument(...)
args=parser.parse_args()
return args
If we are talking about argparse.parse_args from the standard library, just pass the list of arguments explicitly.
For example, if you call your program from the command line with these arguments:
program --verbose --mode=3 file1 file2
the shell splits the command line into five words, the program name and its four arguments. These are stored in sys.argv.
To achieve the same effect directly from Python:
args = parse_args(['--verbose', '--mode=3', 'file1' , 'file2'])
main_function(args)
UPDATE - parse_args modification:
def parse_args(arglist=None):
parser=argparse.ArgumentParser()
parser.add_argument(...)
args=parser.parse_args(arglist)
return args

Argument parser does not accept my data file

Running python 2.7.5 in Spyder, trying to set up an argument parser to import input from a file called data.csv in the same folder as my script. Currently, this part of my function looks like so:
from sys import argv
from argparse import ArgumentParser
def ParseArguments():
parser = ArgumentParser(description='Description of program')
parser.add_argument("-f", type=str, dest="data",
default="", help="Input file", required=True)
parser.add_argument("-o", type=str, dest="output_file",
default="", help="Output file")
parser.add_argument("-p", type=float, dest="first_parameter",
default=0.5, help="First Parameter (decimal)")
parser.add_argument("-n", type=int, dest="second_parameter",
default=0, help="Second Parameter (integer)")
args = parser.parse_args()
def my_function(args):
print "Input file is:", args.data
print "Output file is:", args.output_file
print "Parameter 1 is:", args.first_parameter
print "Parameter 2 is:", args.second_parameter
Then I call it in my main function:
def main(argv):
args = ParseArguments()
my_function(args)
args.data
def read(data):
fh = read(args.data, "data")
(...)
Now, when I try to run this I get the error message:
runfile('C:filepath', wdir='C:/filepath')
usage: code.py [-h] -f DATA [-o OUTPUT_FILE] [-p FIRST_PARAMETER]
[-n SECOND_PARAMETER]
code.py: error: argument -f is required
I can't comprehend how this is not defined - there is a file called data in the working directory, and from my understanding of the argument parser it doesn't care about file types when assigning input, so it should be assigning my data.csv as input. What gives?
Another option might be to just not use the argument parser, of course, and reading the file directly by commands, but I'd like to understand what I've done wrong here all the same.

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