Python实现带GUI的计算器

__author__ = 'joel' from PyQt4 import QtCore, QtGui from Calculator import CalTools class MainWindow(QtGui.QWidget): def __init__(self): QtGui.QWidget.__init__(self) self.setWindowTitle("Calculator") self.resize(300, 300) # layouts self.main_layout = QtGui.QGridLayout() self.edit_line_layout = QtGui.QGridLayout() self.button_layout = QtGui.QGridLayout() # widgets self.label = QtGui.QLabel("Expr:") self.label.setAlignment(QtCore.Qt.AlignCenter) self.edit_line_layout.addWidget(self.label, 0, 0) self.line_edit = QtGui.QLineEdit() self.edit_line_layout.addWidget(self.line_edit, 0, 1) # buttons self.button1 = QtGui.QPushButton("1") self.button2 = QtGui.QPushButton("2") self.button3 = QtGui.QPushButton("3") self.button4 = QtGui.QPushButton("4") self.button5 = QtGui.QPushButton("5") self.button6 = QtGui.QPushButton("6") self.button7 = QtGui.QPushButton("7") self.button8 = QtGui.QPushButton("8") self.button9 = QtGui.QPushButton("9") self.button0 = QtGui.QPushButton("0") self.button_plu = QtGui.QPushButton("+") self.button_sub = QtGui.QPushButton("-") self.button_mut = QtGui.QPushButton("*") self.button_div = QtGui.QPushButton("/") self.button_lbr = QtGui.QPushButton("(") self.button_rbr = QtGui.QPushButton(")") self.button_dot = QtGui.QPushButton(".") self.button_equ = QtGui.QPushButton("=") self.button_back = QtGui.QPushButton("<-") self.button_clear = QtGui.QPushButton("C") # add buttons to layout self.button_layout.addWidget(self.button1, 2, 0) self.button_layout.addWidget(self.button2, 2, 1) self.button_layout.addWidget(self.button3, 2, 2) self.button_layout.addWidget(self.button4, 2, 3) self.button_layout.addWidget(self.button5, 3, 0) self.button_layout.addWidget(self.button6, 3, 1) self.button_layout.addWidget(self.button7, 3, 2) self.button_layout.addWidget(self.button8, 3, 3) self.button_layout.addWidget(self.button9, 4, 0) self.button_layout.addWidget(self.button0, 4, 1) self.button_layout.addWidget(self.button_lbr, 4, 2) self.button_layout.addWidget(self.button_rbr, 4, 3) self.button_layout.addWidget(self.button_mut, 5, 0) self.button_layout.addWidget(self.button_div, 5, 1) self.button_layout.addWidget(self.button_plu, 5, 2) self.button_layout.addWidget(self.button_sub, 5, 3) self.button_layout.addWidget(self.button_dot, 6, 0) self.button_layout.addWidget(self.button_clear, 6, 1) self.button_layout.addWidget(self.button_back, 6, 2) self.button_layout.addWidget(self.button_equ, 6, 3) # add layouts self.main_layout.addLayout(self.edit_line_layout, 0, 0) self.main_layout.addLayout(self.button_layout, 1, 0) # set layout to window self.setLayout(self.main_layout) #connect events to functions self.connect(self.button1, QtCore.SIGNAL('clicked()'), self.on_button1_clicked) self.connect(self.button2, QtCore.SIGNAL('clicked()'), self.on_button2_clicked) self.connect(self.button3, QtCore.SIGNAL('clicked()'), self.on_button3_clicked) self.connect(self.button4, QtCore.SIGNAL('clicked()'), self.on_button4_clicked) self.connect(self.button5, QtCore.SIGNAL('clicked()'), self.on_button5_clicked) self.connect(self.button6, QtCore.SIGNAL('clicked()'), self.on_button6_clicked) self.connect(self.button7, QtCore.SIGNAL('clicked()'), self.on_button7_clicked) self.connect(self.button8, QtCore.SIGNAL('clicked()'), self.on_button8_clicked) self.connect(self.button9, QtCore.SIGNAL('clicked()'), self.on_button9_clicked) self.connect(self.button0, QtCore.SIGNAL('clicked()'), self.on_button0_clicked) # not numbers self.connect(self.button_lbr, QtCore.SIGNAL('clicked()'), self.on_button_lbr_clicked) self.connect(self.button_rbr, QtCore.SIGNAL('clicked()'), self.on_button_rbr_clicked) self.connect(self.button_mut, QtCore.SIGNAL('clicked()'), self.on_button_mut_clicked) self.connect(self.button_div, QtCore.SIGNAL('clicked()'), self.on_button_div_clicked) self.connect(self.button_plu, QtCore.SIGNAL('clicked()'), self.on_button_plu_clicked) self.connect(self.button_sub, QtCore.SIGNAL('clicked()'), self.on_button_sub_clicked) self.connect(self.button_dot, QtCore.SIGNAL('clicked()'), self.on_button_dot_clicked) self.connect(self.button_clear, QtCore.SIGNAL('clicked()'), self.on_button_clear_clicked) self.connect(self.button_back, QtCore.SIGNAL('clicked()'), self.on_button_back_clicked) self.connect(self.button_equ, QtCore.SIGNAL('clicked()'), self.on_button_equ_clicked) self.error_str = "Error" # check whether error occurs, if so clear edit line def check_error(self): if self.error_str == self.line_edit.text(): self.line_edit.setText("") def on_button1_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "1") def on_button2_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "2") def on_button3_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "3") def on_button4_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "4") def on_button5_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "5") def on_button6_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "6") def on_button7_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "7") def on_button8_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "8") def on_button9_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "9") def on_button0_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "0") def on_button_lbr_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "(") def on_button_rbr_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + ")") def on_button_mut_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "*") def on_button_div_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "/") def on_button_plu_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "+") def on_button_sub_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + "-") def on_button_clear_clicked(self): self.line_edit.setText("") def on_button_back_clicked(self): text = self.line_edit.text() if len(text) > 0: self.line_edit.setText(text[0:len(text)-1]) def on_button_dot_clicked(self): self.check_error() self.line_edit.setText(self.line_edit.text() + ".") def on_button_equ_clicked(self): # calculate begin... cal_str = self.line_edit.text() # get string from edit line cal_str = CalTools.str_filter(cal_str) # filter string prefix_stack = CalTools.get_calculator_stack(cal_str) # create a prefix stack # print some logs print "cal str:", cal_str print "prefix stack:" CalTools.print_calculator_stack(prefix_stack) # make prefix to suffix suffix_stack = C