While executing script nothing happens?

Question

My goal is to create a python's script, which will format/modify the xml file. Path to file & filename are to be given as arguments in command line.

Here is my code below:

import lxml.etree as etree
from argparse import ArgumentParser
import sys
import os
def main():
 parser = ArgumentParser()
 parser.add_argument('-p', '--path', help="path to file's directory", required=True)
 parser.add_argument('-f', '--file', help="file name", required=True)
 args = parser.parse_args()
 root_dir = sys.argv[1]
 file_name = sys.argv[2]
 path = sys.argv[1] + sys.argv[2]
 for dirpath, dirnames, files in os.walk(root_dir):
 for file in files:
 if file == file_name:
 print(os.path.join(dirpath, file_name))
 with open(path, 'r', encoding="utf8") as myfile:
 try:
 print("DONE")
 parser = etree.XMLParser(remove_blank_text = True)
 tree = etree.parse(path, parser)
 tree.write(path, pretty_print = True)
 except IOError:
 print("IO Exception Occured")
if __name__ == "__main__":
 main()

When I run it from cmd - I have 0 errors, but the file is not formatted, even though I give the filename that doesn't exist - still no errors. So when I run it from cmd - nothing happens.

When I try to debug it in Visual Studio, there is error that 2 arguments need to be given. Can anybody tell me how to fix my code, I have no idea where I have wrong code?

• David Zemens: When I run this from command line: error: the following arguments are required: -p/--path, -f/--file
• user9664805: Do you run it with arguments?
• freerafiki: You should get an error! How are you running it? If you run from command line you can use the python debugger to set a breakpoint and debug it from command line. Otherwise in visual studio you can pass arguments by going to Properties--> Debug as explained here. Maybe this can help debugging it..
• David Zemens: with/without. same error. show us how you're running it. my guess is that you're mis-using ArgumentParser (I'm familiar with, but never actually use this library so I could be mistaken here)
• freerafiki: I think you are doing two things at the same time. First you are parsing the command line argument into the ArgumentParser (so they will be in args.file and args.path) but then you are reading sys.argv[1] and sys.argv[2] and not using args anymore. You should choose one of the two methods for reading the parameters!

Answer 1

You're misusing/combining/confusing sys.argv and ArgumentParser. This code actually gives you the unexpected result, because your variables are not what you think they are!

root_dir = sys.argv[1]
file_name = sys.argv[2]
# Add some print statements to examine these variables:
print(f'root_dir:{root_dir}')
print(f'file_name:{file_name}')

Look:

enter image description here

Do this instead:

 root_dir = args.path
 file_name = args.file

Here is code I used to test:

from argparse import ArgumentParser
import sys
def main():
 parser = ArgumentParser()
 parser.add_argument('-p', '--path', help="path to file's directory", required=True)
 parser.add_argument('-f', '--file', help="file name", required=True)
 args = parser.parse_args()
 root_dir = args.path
 file_name = args.file
 print(f'root_dir:{root_dir}')
 print(f'file_name:{file_name}')
if __name__ == "__main__":
 main()

• user9664805: Yes, I have done it after reading comments under the post and it works now. Thank you.

Answer 2

You are mixing two things!

METHOD 1

Launch with XmlFormat.py -p c:\User\Desktop\test\ -f test.xml

import lxml.etree as etree
from argparse import ArgumentParser
import sys
import os
def main():
 parser = ArgumentParser()
 parser.add_argument('-p', '--path', help="path to file's directory", required=True)
 parser.add_argument('-f', '--file', help="file name", required=True)
 args = parser.parse_args()
 root_dir = args.path
 file_name = args.file
 path = root_dir + file_name
 for dirpath, dirnames, files in os.walk(root_dir):
 for file in files:
 if file == file_name:
 print(os.path.join(dirpath, file_name))
 with open(path, 'r', encoding="utf8") as myfile:
 try:
 print("DONE")
 parser = etree.XMLParser(remove_blank_text = True)
 tree = etree.parse(path, parser)
 tree.write(path, pretty_print = True)
 except IOError:
 print("IO Exception Occured")
if __name__ == "__main__":
 main()

METHOD 2

Launch with XmlFormat.py c:\User\Desktop\test\ test.xml (do not use -p and -f)

import lxml.etree as etree
from argparse import ArgumentParser
import sys
import os
def main():
 root_dir = sys.argv[1]
 file_name = sys.argv[2]
 path = root_dir + file_name
 for dirpath, dirnames, files in os.walk(root_dir):
 for file in files:
 if file == file_name:
 print(os.path.join(dirpath, file_name))
 with open(path, 'r', encoding="utf8") as myfile:
 try:
 print("DONE")
 parser = etree.XMLParser(remove_blank_text = True)
 tree = etree.parse(path, parser)
 tree.write(path, pretty_print = True)
 except IOError:
 print("IO Exception Occured")
if __name__ == "__main__":
 main()