如何在python中的argparse参数中传递输入

Question

this code should ask 2 optional and 1 required argument, 'format' and 'type' argument are optional and 'url' is required argument which will be the address of website from where you wants to download image(either jpg or/and .png type image,depend on what value you give in 'type' argument ) and save it as either as individual image or single JSON file(depend on what value you give in 'format' argument ), i am getting error can you tell where i am going wrong,here is my code..

import argparse
import base64
import json
import os
from bs4 import BeautifulSoup
import requests



def scrape(url,format_,type_):
    try:
        page = requests.get(url)
    except requests.RequestException as rex:
        print(str(rex))
    else:
        soup = BeautifulSoup(url,'html.parser')
        images = _fetch_images(soup,url)
        images = _filter_images(images,type_)
        _save(images,format_)

def _fetch_images(soup,base_url):
    images = []
    for img in soup.find_all('img'):
        src = img.get('src')
        img_url = ('{base_url}/{src}'.format(base_url,src))
        name = img_url.split('\\')[-1]
        images.append(dict(name=name,url=img_url))
return images

def _filter_images(images,type_):
    if type == 'all':
        return images
    ext_map = {'png':['.png'],'jpg':['.jpg','.jpeg']}
    return [img for img in images if 
            _match_extension(img['name'],ext_map(type_))]

def _match_extension(filename,extension_list):
    name,extension = os.path.splittext(filename.lower())
    return extension in extension_list

def _save(images,format_):
    if images:
        if format_=='img':
            _save_images(images)
        else:
            _save_json(images)
            print('Done!')
    else:
        print('there are no images!')

def _save_images(images):
    for img in images:
        img_data = requests.get(img['url']).content
        with open(img['name'],'wb') as f:
        f.write(img_data)

def _save_json(images):
    data = {}
    for img in images:
        img_data = requests.get(img['url']).content
        b64_img_data = base64.b64encode(img_data)
        str_img_data = b64_img_data.decode('utf-8')
        data[img['name']]=str_img_data
    with open('images.json','w') as ijson:
        ijson.write(json.dump(data))


if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        description='Scrape a webpage.')
    parser.add_argument(
        '-t',
        '--type',
        choices=['all', 'png', 'jpg'],
        default='all',
        help='The image type we want to scrape.')
    parser.add_argument(
        '-f',
        '--format',
        choices=['img', 'json'],
        default='img',
        help='The format images are saved to.')
    parser.add_argument(
        'url',
        help='The URL we want to scrape for images.')
    args = parser.parse_args()
    args.url = str(input('enter the url\n'))
    args.format = str(input('enter img or json \n'))
    args.type = str(input('enter all or png or jpg'))
    scrape(args.url,args.format,args.type)

i wants to run it in PyCharm and error i got is,

usage: scrape.py [-h] [-t {all,png,jpg}] [-f {img,json}] url
scrape.py: error: the following arguments are required: url 

Answer 1

In order to pass parameters to your function in Pycharm, navigate to Run -> Edit Configurations and set the parameters there.

Alternatively, try invoking your program with parameters specified from the command line.