pyQt5 计算器

参考:  PyQt5中文教程

'''
思路:
    设置按钮，
    添加到网格布局中

    为按钮添加功能

    解决问题：
        除零 报错
        等号后 直接按数字问题

'''

import sys
from PyQt5.QtWidgets import QWidget, QApplication, QLineEdit, QPushButton, QGridLayout, QHBoxLayout, QVBoxLayout
from PyQt5.QtGui import QIcon, QFont
from PyQt5.QtCore import Qt


class Calculater(QWidget):
    def __init__(self):
        super().__init__()

        self.initUI()
        # 初始化属性值
        self.reset()


    def initUI(self):

        # 创建窗口标题
        self.setWindowTitle("计算器")
        self.setWindowIcon(QIcon("icon.ico"))
        # 网格布局
        gridLayout =  QGridLayout()

        # 设置文本
        self.lineEdit = QLineEdit("0")
        # 文本从右面开始显示
        self.lineEdit.setAlignment(Qt.AlignRight)
        # 禁止直接输入 只读
        self.lineEdit.setReadOnly(True)
        # 设置显示文本得到字体
        self.lineEdit.setFont(QFont("Times", 20))
        # 设置最多显示的数字长度
        self.lineEdit.setMaxLength(15)
        # 创建按钮
        # btn = QPushButton()

        # 创建
        names = [
            "AC", "Del", "", "close",
            "7",  "8", "9", "+",
            "4",  "5", "6", "-",
            "1", "2", "3", "*",
            "0", ".", "=", "/",
        ]

        grids = [(i, j) for i in range(1, 6) for j in range(0, 4)]
        # 将单行文本框加入布局
        gridLayout.addWidget(self.lineEdit, 0, 0, 1, 4)
        # 构建表格
        for grid, name in zip(grids, names):

            btn = QPushButton(name)
            btn.resize(btn.sizeHint())
            btn.setFixedSize(60, 30)
            btn.clicked.connect(self.buttonClick)

            # if name == "0":
            #     # 后边的四个参数分别是 行 ， 列， 行跨度， 列跨度
            #     print(grid[1])
            #     gridLayout.addWidget(QPushButton(name), grid[0], grid[1], 1, 2)
            # elif name == ".":
            #     gridLayout.addWidget(QPushButton(name), grid[0], grid[1]+1, 1, 1)
            # elif name == "=":
            #     btn = QPushButton(name)
            #
            #     gridLayout.addWidget(btn, grid[0], grid[1], 2, 1)
            # else:
            #     gridLayout.addWidget( QPushButton(name), *grid)
            if name == "":
                continue
            else:
                gridLayout.addWidget(btn, *grid)

        self.setLayout(gridLayout)
        self.show()

    def buttonClick(self):
        # 获取number
        text = self.sender().text()
        if text in "+-*/":
            self.string += text
            # 用来存储表达式
            self.number = ""
            # 在这里如果继续执行的话在界面展示会有问题所以退出
            self.last = text
            return
        # 用eval的话不需要判断点
        # elif text == ".":

        elif text == "=":
            self.resault()
            return

        elif text == "AC":
            self.reset()
        elif text == "Del":
            self.deleat()
        elif text == "close":
            self.close()

        else:
            # 如果之前已经按了等号在按数字的话清空之前的值
            if self.last == "=" and type(eval(text)) == int:
                self.reset()
            # 除零判断
            elif self.last == "/" and text == "0":
                self.number = "error"
                self.lineEdit.setText(self.number)
                return
            # 如果 self.number ！= 0 self.number = self.number + text 否则 self.number = text
            self.number = self.number + text if self.number != "0" else text
            self.string += text
            # 用来记录按键
        self.lineEdit.setText(self.number)


    def resault(self):

        self.lineEdit.setText(str(eval(self.string)))
        # 这一个设置每次运算完后直接将结果改变
        self.string = str(eval(self.string))
        self.number = ""
        self.last = "="



    def reset(self):
        #重置用来接收按钮数字
        self.number = "0"
        # 重置用来存储按钮数字和运算符的字符串
        self.string = ""
        self.last = ""
        self.symbol = ""

    def deleat(self):
        self.string = self.string[0:-1]
        # self.number = self.number[0:-1]
        # # 如果self.number 的删除后为空则设置为0
        # if not self.number:
        #     self.number = "0"
        # 间写
        self.number = self.number[0: -1] if self.number[0: -1] else "0"


if __name__ == "__main__":
    app = QApplication(sys.argv)
    ex = Calculater()
    sys.exit(app.exec_())