[FOR DISCUSSION ONLY] Untested CLI script using pyODK

request.py

import argparse
import json
import re
import sys
import urllib.parse
from mimetypes import guess_type
from pathlib import Path
from pyodk.client import Client

parser = argparse.ArgumentParser()
parser.add_argument('url')
parser.add_argument('--config')
parser.add_argument('--cache')
parser.add_argument('-X', '--request', default='get')
parser.add_argument('--json', nargs='?', const=True)
parser.add_argument('--xml', nargs='?', const=True)
parser.add_argument('-f', '--file')
parser.add_argument('-H', '--header', nargs=2, action='append')
parser.add_argument('-e', '--extended', action='store_true')
parser.add_argument('-i', '--include', action='store_true')
parser.add_argument('-o', '--output', nargs='?', const=True)
args = parser.parse_args()

# Use --config and --cache to create the client.
client = Client(config_path=args.config, cache_path=args.cache)

# --request
method = args.request.lower()
if method not in ['get', 'post', 'put', 'patch', 'delete']:
    raise Exception('--request: invalid method')

# Request data: --json, --xml, and --file
data = None
headers = {}
if args.json is not None and args.xml is not None:
    raise Exception('--json and --xml cannot both be specified')
if args.json is not None:
    data = args.json
    headers['content-type'] = 'application/json'
elif args.xml is not None:
    data = args.xml
    headers['content-type'] = 'application/xml'
    headers['x-openrosa-version'] = '1.0'
if args.file is not None:
    if isinstance(args.json, str):
        raise Exception('cannot pass a string to --json and specify --file')
    if isinstance(args.xml, str):
        raise Exception('cannot pass a string to --xml and specify --file')
    # TODO. Do we need to distinguish between ASCII and binary files? request()
    # seems to want bytes, never a string.
    with open(args.file, 'rb') as f: data = f.read()
if data is not None and method in ['get', 'delete']:
    raise Exception(f'data not allowed for {method.upper()} request')
if data is True: data = sys.stdin.read()

# XLSForms
if args.file is not None:
    file_path = Path(args.file)
    if file_path.suffix.lower() in ['.xlsx', '.xls']:
        headers['content-type'] = guess_type(args.file)
        headers['x-xlsform-formid-fallback'] = file_path.stem

# --header and --extended
if args.extended: headers['x-extended-metadata'] = 'true'
# Headers specified using --header take precedence over other headers.
if args.header is not None:
    # We need to call lower() to ensure that an existing header is overwritten.
    for name, value in args.header: headers[name.lower()] = value
    # Encode Central custom headers.
    for name in ['x-xlsform-formid-fallback', 'x-action-notes']:
        if name in headers: headers[name] = urllib.parse.quote(headers[name])

# Send the request.
response = client.session.request(method, args.url, data=data, headers=headers)

# --include
# If --output was also specified, the status and headers are still printed, not
# written to file.
if args.include:
    print(f'{response.status_code} {response.reason}')
    for name, value in response.headers.items(): print(f'{name}: {value}')
    if args.output is None: print('')

# Print the response data or, if --output was specified, save it to disk.
if args.output is None:
    if re.match(r'^attachment(;|$)', response.headers.get('Content-Disposition', '')):
        print('The response is an attachment. Use --output to save it to disk.')
    elif re.match(r'^application/json(;|$)', response.headers['Content-Type']):
        print(json.dumps(response.json(), indent=4))
    # Probably XML?
    else:
        print(response.content.decode('utf-8'))
else:
    # Determine the file path at which to write the response data (output_path).
    if args.output is not True:
        output_path = args.output
    else:
        if 'Content-Disposition' not in response.headers:
            print('The response did not return a Content-Disposition header. You must specify a filename to --output.')
            sys.exit(0)
        content_disposition = response.headers['Content-Disposition']
        if re.match(r'^attachment(;|$)', content_disposition) is None:
            print('The response did not return an attachment Content-Disposition header. You must specify a filename to --output.')
            sys.exit(0)
        match = re.match(r"; filename\*=UTF-8''([^; ]+)", content_disposition)
        if match is None:
            raise Exception('unexpected Content-Disposition header')
        output_path = urllib.parse.unquote(match.group(1))

    with open(output_path, 'wb') as f: f.write(response.content)