Не запускается код переформатированный из .ui в .py

Создайте другой класс, который наследуется от соответствующего виджета, и используйте созданный класс для его заполнения.

from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.setWindowModality(QtCore.Qt.ApplicationModal)
        MainWindow.setEnabled(True)
        MainWindow.resize(830, 500)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Maximum, QtWidgets.QSizePolicy.Preferred)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
        MainWindow.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setPointSize(6)
        font.setBold(False)
        font.setItalic(False)
        font.setUnderline(False)
        font.setWeight(50)
        font.setStrikeOut(False)
        font.setKerning(False)
        font.setStyleStrategy(QtGui.QFont.PreferDefault)
        MainWindow.setFont(font)
        MainWindow.setCursor(QtGui.QCursor(QtCore.Qt.ArrowCursor))
        MainWindow.setMouseTracking(True)
        MainWindow.setTabletTracking(True)
        MainWindow.setFocusPolicy(QtCore.Qt.ClickFocus)
        MainWindow.setContextMenuPolicy(QtCore.Qt.DefaultContextMenu)
        MainWindow.setWindowOpacity(1.0)
        MainWindow.setToolTip("")
        MainWindow.setStatusTip("")
        MainWindow.setAccessibleName("")
        MainWindow.setAccessibleDescription("")
        MainWindow.setAutoFillBackground(False)
        MainWindow.setStyleSheet("QDateEdit\n"
"{\n"
"    background-color: white;\n"
"    border-style: solid;\n"
"    border-width: 2px;\n"
"    border-color: rgb(100,100,100);\n"
"    spacing: 5px; \n"
"}\n"
"\n"
"\n"
"QDateEdit::drop-down {\n"
"\n"
"    width:50px;\n"
"    height:15px;\n"
"    subcontrol-position: right top;\n"
"    subcontrol-origin:margin;\n"
"    background-color: white;\n"
"    border-style: solid;\n"
"    border-width: 4px;\n"
"    border-color: rgb(100,100,100);\n"
"   spacing: 5px; \n"
"}")
        MainWindow.setInputMethodHints(QtCore.Qt.ImhNone)
        MainWindow.setIconSize(QtCore.QSize(121, 23))
        MainWindow.setToolButtonStyle(QtCore.Qt.ToolButtonIconOnly)
        MainWindow.setAnimated(False)
        MainWindow.setDocumentMode(False)
        MainWindow.setTabShape(QtWidgets.QTabWidget.Triangular)
        MainWindow.setDockNestingEnabled(False)
        MainWindow.setUnifiedTitleAndToolBarOnMac(False)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.calendar = QtWidgets.QCalendarWidget(self.centralwidget)
        self.calendar.setGeometry(QtCore.QRect(30, 120, 801, 381))
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Maximum, QtWidgets.QSizePolicy.Maximum)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.calendar.sizePolicy().hasHeightForWidth())
        self.calendar.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setFamily("Leelawadee UI Semilight")
        font.setPointSize(12)
        font.setBold(False)
        font.setItalic(False)
        font.setUnderline(False)
        font.setWeight(50)
        self.calendar.setFont(font)
        self.calendar.setMouseTracking(True)
        self.calendar.setTabletTracking(True)
        self.calendar.setFocusPolicy(QtCore.Qt.ClickFocus)
        self.calendar.setContextMenuPolicy(QtCore.Qt.ActionsContextMenu)
        self.calendar.setAcceptDrops(True)
        self.calendar.setToolTip("")
        self.calendar.setToolTipDuration(-1)
        self.calendar.setWhatsThis("")
        self.calendar.setAccessibleName("")
        self.calendar.setStyleSheet("selection-background-color: rgb(245, 245, 245);\n"
"")
        self.calendar.setInputMethodHints(QtCore.Qt.ImhDate)
        self.calendar.setGridVisible(False)
        self.calendar.setVerticalHeaderFormat(QtWidgets.QCalendarWidget.NoVerticalHeader)
        self.calendar.setNavigationBarVisible(False)
        self.calendar.setDateEditEnabled(False)
        self.calendar.setDateEditAcceptDelay(1500)
        self.calendar.setObjectName("calendar")
        self.dateEdit = QtWidgets.QDateEdit(self.centralwidget)
        self.dateEdit.setEnabled(True)
        self.dateEdit.setGeometry(QtCore.QRect(30, 100, 121, 21))
        self.dateEdit.setMinimumSize(QtCore.QSize(121, 21))
        self.dateEdit.setMaximumSize(QtCore.QSize(121, 21))
        palette = QtGui.QPalette()
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Active, QtGui.QPalette.Button, brush)
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Active, QtGui.QPalette.Base, brush)
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Active, QtGui.QPalette.Window, brush)
        brush = QtGui.QBrush(QtGui.QColor(215, 228, 237))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Active, QtGui.QPalette.Highlight, brush)
        brush = QtGui.QBrush(QtGui.QColor(67, 156, 172))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Active, QtGui.QPalette.HighlightedText, brush)
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Inactive, QtGui.QPalette.Button, brush)
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Inactive, QtGui.QPalette.Base, brush)
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Inactive, QtGui.QPalette.Window, brush)
        brush = QtGui.QBrush(QtGui.QColor(215, 228, 237))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Inactive, QtGui.QPalette.Highlight, brush)
        brush = QtGui.QBrush(QtGui.QColor(67, 156, 172))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Inactive, QtGui.QPalette.HighlightedText, brush)
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Disabled, QtGui.QPalette.Button, brush)
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Disabled, QtGui.QPalette.Base, brush)
        brush = QtGui.QBrush(QtGui.QColor(255, 255, 255))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Disabled, QtGui.QPalette.Window, brush)
        brush = QtGui.QBrush(QtGui.QColor(215, 228, 237))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Disabled, QtGui.QPalette.Highlight, brush)
        brush = QtGui.QBrush(QtGui.QColor(67, 156, 172))
        brush.setStyle(QtCore.Qt.SolidPattern)
        palette.setBrush(QtGui.QPalette.Disabled, QtGui.QPalette.HighlightedText, brush)
        self.dateEdit.setPalette(palette)
        font = QtGui.QFont()
        font.setFamily("Bahnschrift")
        font.setPointSize(11)
        font.setBold(False)
        font.setItalic(False)
        font.setWeight(50)
        self.dateEdit.setFont(font)
        self.dateEdit.setMouseTracking(True)
        self.dateEdit.setTabletTracking(False)
        self.dateEdit.setFocusPolicy(QtCore.Qt.WheelFocus)
        self.dateEdit.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
        self.dateEdit.setAcceptDrops(False)
        self.dateEdit.setToolTipDuration(-1)
        self.dateEdit.setStyleSheet("")
        self.dateEdit.setInputMethodHints(QtCore.Qt.ImhDate)
        self.dateEdit.setWrapping(False)
        self.dateEdit.setFrame(False)
        self.dateEdit.setAlignment(QtCore.Qt.AlignLeading|QtCore.Qt.AlignLeft|QtCore.Qt.AlignVCenter)
        self.dateEdit.setReadOnly(False)
        self.dateEdit.setAccelerated(False)
        self.dateEdit.setProperty("showGroupSeparator", False)
        self.dateEdit.setCalendarPopup(False)
        self.dateEdit.setObjectName("dateEdit")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(350, 50, 60, 21))
        self.pushButton.setStyleSheet("pushButton {\n"
"    position: relative; top: 0;\n"
"    background: #333; color: #fff;\n"
"    box-shadow: 0 6px rgb(255, 190, 186);\n"
"    transition: 0.05s !important;\n"
"    border-radius: 5px;\n"
"    padding: 10px 24px;\n"
"}\n"
"pushButton:hover {\n"
"    top: 3px;\n"
"    box-shadow: 0 3px rgb(255, 93, 78);\n"
"}\n"
"pushButton:active {\n"
"    top: 6px;\n"
"    box-shadow: 0 0 rgb(255, 38, 0);\n"
"}")
        self.pushButton.setText("")
        self.pushButton.setIconSize(QtCore.QSize(65, 60))
        self.pushButton.setCheckable(False)
        self.pushButton.setAutoRepeat(False)
        self.pushButton.setAutoExclusive(False)
        self.pushButton.setObjectName("pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.actiond = QtWidgets.QAction(MainWindow)
        self.actiond.setObjectName("actiond")
        self.actionf = QtWidgets.QAction(MainWindow)
        self.actionf.setObjectName("actionf")
        self.actionfd = QtWidgets.QAction(MainWindow)
        self.actionfd.setObjectName("actionfd")
        self.actionfd_2 = QtWidgets.QAction(MainWindow)
        self.actionfd_2.setObjectName("actionfd_2")
        self.actiondf = QtWidgets.QAction(MainWindow)
        self.actiondf.setObjectName("actiondf")
        self.actiondf_2 = QtWidgets.QAction(MainWindow)
        self.actiondf_2.setObjectName("actiondf_2")
        self.actiondf_3 = QtWidgets.QAction(MainWindow)
        self.actiondf_3.setObjectName("actiondf_3")

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.dateEdit.setDisplayFormat(_translate("MainWindow", "dd.MM.yyyy"))
        self.actiond.setText(_translate("MainWindow", "d"))
        self.actionf.setText(_translate("MainWindow", "f"))
        self.actionfd.setText(_translate("MainWindow", "fd"))
        self.actionfd_2.setText(_translate("MainWindow", "fd"))
        self.actiondf.setText(_translate("MainWindow", "df"))
        self.actiondf_2.setText(_translate("MainWindow", "df"))
        self.actiondf_3.setText(_translate("MainWindow", "df"))
        
        

class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self):                 
        super().__init__()
        
        self.setupUi(self)
        
        # + тут ваша логика
        
        
if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    p = MainWindow()
    p.show()
    sys.exit(app.exec_())