使用 'argparse' 而不是 sys.argv [英] Using 'argparse' as opposed to sys.argv

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本文介绍了使用 'argparse' 而不是 sys.argv的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我的脚本当前使用 sys.argv 来检查提供给程序的输入文件.

My script currently uses sys.argv to check for an input file provided to the program.

我正在尝试使用 argparse 代替,但我似乎无法让它工作.我能够设置它并添加一个参数,但是当我解析一个参数并打印该解析后的参数时,我得到了一个命名空间.我怎样才能得到一个字符串?基本上,我想将参数作为字符串,然后打开一个具有该名称的文件.

I am trying to utilise argparse instead but I cant seem to get it to work. I was able to set it up and add an argument, but when I parse an argument, and print that parsed argument, I get a namespace. How can I get a string? Basically, I want to take the argument as a string, and open a file with that name.

目前,我的 sys.argv 是:

filename = sys.argv[1]
f = open(filename, 'r')

我的 argparse 打印出一个 Namespace 如下:

My argparse prints out a Namespace as follows:

arg = parser.parse_args()
print arg

如何使用它来打开文件?我想使用 argparse 因为参数的错误处理要容易得多.

How can I use that to open a file? I want to use argparse since the error handlign for arguments there is a lot easier.

推荐答案

认为使用 with 语句打开文件更可取(或其他!):

think its preferable (or something!) to use the with statement to open the file like this:

# printfile.py
import argparse

parser = argparse.ArgumentParser(description="Opens a file and does cool stuff ^^")
parser.add_argument('filename', type=str, help="Path to file to open")
args = parser.parse_args()

with open(args.filename) as f:
    print '   my uber cool file:'
    print f.readlines()

指定这些关键字参数也有助于制作一个漂亮的 -h 帮助文本选项(非常整洁)

specifying those keyword args also helps make a pretty -h help text option (which is neat neat)

[dlam@dlam-63221:~] $ python printfile.py -h
usage: printfile.py [-h] filename

Opens a file and does cool stuff ^^

positional arguments:
    filename    Path to file to open

这篇关于使用 'argparse' 而不是 sys.argv的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!

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