WIP. a wrapper about integrate.

int.py

"""
usage: python3 this_file.py expr
for example:
python3 this_file.py "tan(x)"
python3 this_file.py "^(x,-1)"
python3 this_file.py "+(x,-1)"
python3 this_file.py "+(-1,x,^(x,-1))"
"""

import json
import sys
import uuid
from typing import Dict, List, Union

import requests
from lxml.etree import HTML


def query_int(expr: str):
    """
    get result of int
    """
    cookies = {
        "consentUUID": uuid.uuid4().hex,
        "gdpr": "0",
    }

    headers = {
        "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4658.57 Safari/537.36",
        "Origin": "https://www.integral-calculator.com",
        "Referer": "https://www.integral-calculator.com/",
    }
    data_q: Dict[str, Union[str, int, bool]] = json.loads(
        '{"expressionCanonical":"x","intVar":"x","complexMode":false,"keepDecimals":false,"alternatives":{},"f":"F","maximaFoundAnElementaryAntiderivative":true}'
    )
    data_q["expressionCanonical"] = expr
    data = {
        "q": json.dumps(data_q),
        "v": "1630214470",
    }
    response = requests.post(
        "https://www.integral-calculator.com/manualint.php",
        headers=headers,
        cookies=cookies,
        data=data,
    )
    return response.text


def extract_results(results: str) -> List[str]:
    """
    extract result from html
    """
    html = HTML(results)  # type: ignore
    return html.xpath("//div[starts-with(@class, 'calc-math')]/text()")


def main(expr: str):
    """main function"""
    tex = extract_results(query_int(expr))
    print(*tex, sep="\n")


main(sys.argv[1])