PyQt5 简易计算器

剩下计算函数(self.calculator)未实现，有兴趣的朋友可以实现它

【知识点】

1、利用循环添加按钮部件，及给每个按钮设置信号/槽

2、给按钮设置固定大小：button.setFixedSize(QtCore.QSize(60,30))

3、取事件的的发送者（此例为各个按钮）的文本： self.sender().text()

【效果图】

【源代码】

 import sys
 from PyQt5 import QtWidgets,QtCore,QtGui

 class Example(QtWidgets.QWidget):

     def __init__(self):
         super(Example, self).__init__()
         self.initUI()

         self.reset()

     def initUI(self):
         self.setWindowTitle('简易计算器')
         grid = QtWidgets.QGridLayout()

         self.display = QtWidgets.QLineEdit('')
         self.display.setFont(QtGui.QFont("Times", 20))
         self.display.setReadOnly(True)
         self.display.setAlignment(QtCore.Qt.AlignRight)
         self.display.setMaxLength(15)
         grid.addWidget(self.display,0,0,1,4)

         names = ['Clear', 'Back', '', 'Close',
                 '', '', '', '/',
                 '', '', '', '*',
                 '', '', '', '-',
                 '', '.', '=', '+']
         pos = [(0, 0), (0, 1), (0, 2), (0, 3),
                 (1, 0), (1, 1), (1, 2), (1, 3),
                 (2, 0), (2, 1), (2, 2), (2, 3),
                 (3, 0), (3, 1), (3, 2), (3, 3 ),
                 (4, 0), (4, 1), (4, 2), (4, 3)]
         c = 0
         for name in names:
             button = QtWidgets.QPushButton(name)
             button.setFixedSize(QtCore.QSize(60,30))
             button.clicked.connect(self.buttonClicked) # 给每个按钮设置信号/槽
             if c == 2:
                 pass
                 #grid.addWidget(QtWidgets.QLabel(''), 0, 2) #替换 第三个按钮 为 文本标签！
             else:
                 grid.addWidget(button, pos[c][0]+1, pos[c][1])
             c = c + 1

         self.setLayout(grid)

     def buttonClicked(self):
         #sender = self.sender();  # 确定信号发送者
         #self.display.setText(sender.text())
         text = self.sender().text()
         if text in '+-*/':
             self.history.append(self.number) # 数字入栈
             self.history.append(text) # 运算符入栈
             self.operator = text # 设置当前运算符
             self.number = "" # 数字清空
             self.numberType = "int"
             return
         elif text == "=":
             self.calculate() # 计算
         elif text == "Back":
             pass
         elif text == "Clear":
             self.reset()
         elif text == "Close":
             self.close()
         elif text == ".":
             if self.numberType == "int":
                 self.number += text
                 self.numberType = "float"
         else:
             self.number = self.number + text if self.number != "" else text

         self.display.setText(self.number)

     def calculate(self):
         pass

     def reset(self):
         self.number = ""
         self.result = 0
         self.history = []
         self.operator = '' # +,-,*,/
         self.numberType = 'int' # int与float两种，如果输入了小数点则为实数

 app = QtWidgets.QApplication(sys.argv)
 ex = Example()
 ex.show()
 sys.exit(app.exec_())