calc.py

from PyQt6.QtWidgets import QApplication, QLabel, QTextEdit, QVBoxLayout, QWidget, QPushButton
import sys
import ast


def multiline_eval(expr, context={}):
    "Evaluate several lines of input, returning the result of the last line"
    tree = ast.parse(expr)
    eval_exprs = []
    exec_exprs = []
    for module in tree.body:
        if isinstance(module, ast.Expr):
            eval_exprs.append(module.value)
        else:
            exec_exprs.append(module)
    exec_expr = ast.Module(exec_exprs, type_ignores=[])
    exec(compile(exec_expr, 'file', 'exec'), context)
    results = []
    for eval_expr in eval_exprs:
        results.append(eval(compile(ast.Expression((eval_expr)), 'file', 'eval'), context))
    return '\n'.join([str(r) for r in results])


app = QApplication(sys.argv)
window = QWidget()
window.setWindowTitle('Calculator')

layout = QVBoxLayout()
expr = QTextEdit('')
result = QLabel('')


def btn_clicked():
    text = expr.toPlainText()
    try:
        res = multiline_eval(text)
    except Exception as e:
        print(e)
        res = 'Wrong input!'
    result.setText(str(res))


btn = QPushButton('calc')
layout.addWidget(expr)
layout.addWidget(result)
layout.addWidget(btn)
window.setLayout(layout)

btn.clicked.connect(btn_clicked)

window.show()
sys.exit(app.exec())

calc2.py

from PyQt6.QtWidgets import QApplication, QLabel, QTextEdit, QVBoxLayout, QWidget, QPushButton
import sys
import ast
import math
from io import StringIO


def multiline_eval(expr, context={}):
    "Evaluate several lines of input, returning the result of the last line"
    tree = ast.parse(expr)
    eval_exprs = []
    exec_exprs = []
    sys.stdout = new_stdout = StringIO()
    for module in tree.body:
        if isinstance(module, ast.Expr):
            eval_exprs.append(module.value)
        else:
            exec_exprs.append(module)
    exec_expr = ast.Module(exec_exprs, type_ignores=[])
    exec(compile(exec_expr, 'file', 'exec'), context)
    results = []
    for eval_expr in eval_exprs:
        res = str(eval(compile(ast.Expression((eval_expr)), 'file', 'eval'), context))
        size = math.ceil(len(res) / 170)
        for j in range(size-1):
            results.append(res[j*170:(j+1)*170])
        results.append(res[(size-1)*170:])
    sysout = new_stdout.getvalue()
    return '\n'.join(results), sysout


app = QApplication(sys.argv)
window = QWidget()
window.setWindowTitle('Calculator')

layout = QVBoxLayout()
expr = QTextEdit('')
result = QLabel('')
result.setMaximumWidth(1200)


def btn_clicked():
    text = expr.toPlainText()
    try:
        res, sysout = multiline_eval(text)
        if len(res) == 0:
            res = '<No output>'
        if sysout != '':
            res += '\nsys.stdout:\n' + sysout
    except Exception as e:
        print(e)
        res = '<Wrong input>'
    result.setText(str(res))


btn = QPushButton('calc')
btn_exit = QPushButton('exit')
layout.addWidget(expr)
layout.addWidget(result)
layout.addWidget(btn)
layout.addWidget(btn_exit)
window.setLayout(layout)

btn.clicked.connect(btn_clicked)
btn_exit.clicked.connect(lambda: sys.exit())

window.show()
sys.exit(app.exec())