Python3 file accessing

Question

Long story short I want to do a project but don't even know where to start or how to describe it for a google search.

When I run my python file in the Command Prompt I want to be able put a text file next to it that my program will read.
Like: D:> python3 name_of_file.py name_of_text_file.txt

Now when I execute the above I want my python file to somehow see the text file to do something with it (like outputting the contents) but I don't know how to do that. Any suggestions?

Now since I don't know where to start I do not have anything to show on what I have already tried.
Incase it helps: I am using Atom. & The python file and the text file are saved in the same folder.

Xukrao · Accepted Answer · 2022-01-23T18:54:54.163

0

Within a python script you can use the list sys.argv. The first list element (sys.argv[0]) is the name of the python script file (in your case "name_of_file.py"). The rest of the list elements are the provided command line arguments. So sys.argv[1] will contain the first command line argument.

import sys

# Retrieve first command line argument
file_name = sys.argv[1]

# Open text file
with open(file_name) as file:
    # Read out contents of text file
    file_text = file.read()
    
    print(file_text)

edited Jan 23 '22 at 18:54

answered Jan 23 '22 at 18:49

Xukrao

6,984
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Thank you for your detailed explanation on what exactly is happening in the code. That is how people learn and get better. – ianmw7777 Jan 23 '22 at 19:07

Didlly · Answer 2 · 2022-01-23T18:55:18.920

-2

You can use argparse to parse command line arguments.

from argparse import ArgumentParser

parser = ArgumentParser(description="Script Name")

parser.add_argument("file_path", help="The path of the text file.", type=str)

args = parser.parse_args()

with open(args.file_path, "r") as test:
    print(test.read())

edited Jan 23 '22 at 18:55

answered Jan 23 '22 at 18:27

Didlly

87
7

Is there a way where I do not have to specify the text file's path in my code? I would like to specify the text file in question in the command prompt where I am executing the code. – ianmw7777 Jan 23 '22 at 18:52
2

@ianmw7777 I don't understand what you mean. The file path is never specified in the code. The code I have included reads the file path from the command line arguments. Just run 'python3 name_of_file.py name_of_text_file.txt' – Didlly Jan 23 '22 at 18:53
You have "The path of the text file." in the code you included and I don't want to have to specify the whole path of the text file just the name. Is that even possible? – ianmw7777 Jan 23 '22 at 18:56
@ianmw7777 If the file is in the same directory as the Python script, it is possible. If the file is in a different directory, it is not possible. Even if you just specify the file's name, you have to specify it's extension (e.g. '.txt'). – Didlly Jan 23 '22 at 18:58
Thank you for your help and time Didlly. – ianmw7777 Jan 23 '22 at 19:05
1

@Didlly The file needs to be in the _invoking user's current working directory._ See [What exactly is current working directory?](https://stackoverflow.com/questions/45591428/what-exactly-is-current-working-directory/66860904) – tripleee Jan 23 '22 at 20:00

Python3 file accessing

2 Answers2