Placing a Seaborn figure within a Pyqt5 Widget

I'd like to place 3 graphs made using seaborn, which has been passed from a different function in different python file via a dictionary, inside 3 different pyQT widgets I created in pyQT designer. I will post my code below and clarify further:

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):

        glycerate_PT_Graphs = glycerate_PT.get_PT() #get dictionary of graphs

        fig1 = glycerate_PT_Graphs['Level 1'] 
        fig2 = glycerate_PT_Graphs['Level 2']
        fig3 = glycerate_PT_Graphs['Level 3']

        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(1150, 771)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.Level1 = QtWidgets.QWidget(self.centralwidget)    #How to make this object a graph/figure?
        self.Level1.setGeometry(QtCore.QRect(520, 90, 241, 131))
        self.Level1.setObjectName("Level1")
        self.Level2 = QtWidgets.QWidget(self.centralwidget)
        self.Level2.setGeometry(QtCore.QRect(520, 250, 241, 121))
        self.Level2.setObjectName("Level2")
        self.Level3 = QtWidgets.QWidget(self.centralwidget)
        self.Level3.setGeometry(QtCore.QRect(520, 390, 241, 131))
        self.Level3.setObjectName("Level3")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 1150, 20))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))

Additionally, here is what is stored inside the dictionary.

    def graph_PrecisionTotal(self, key, df):
        sns.set_style('darkgrid')
        fig, ax = plt.subplots()
        ax = sns.boxplot(x='Date', y='Calculated Concentration', data=df, width=0.2, whis=10)
        ax.set_title(str(self.analyte_name) + ' ' + key)
        fig = ax.get_figure()
        self.QCgraphs[key] = fig

I would simply like these 'self.Level1', 'self.Level2', and 'self.Level3' QtWidget objects to be seaborn graphs. How can I make that happen?

Solution

You should consider:

Do not modify the class generated by Qt Designer so you must remove the glycerate_PT_Graphs code in setupUi. In my demo the file generated by pyuic is called gui.py
If you are going to use matplotlib in PyQt then you must use FigureCanvas (See the official tutorial).
Seaborn methods have a parameter ax where the ax of the canvas is passed.

from PyQt5 import QtCore, QtGui, QtWidgets

from matplotlib.backends.backend_qt5agg import FigureCanvas
from matplotlib.figure import Figure

import seaborn as sns

from gui import Ui_MainWindow


class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)

        sns.set_theme(style="darkgrid")
        tips = sns.load_dataset("tips")

        self.plot(self.ui.Level1, tips, "plot1")
        self.plot(self.ui.Level2, tips, "plot2")
        self.plot(self.ui.Level3, tips, "plot3")

    def plot(self, widget, df, title):
        canvas = FigureCanvas(Figure())
        ax = canvas.figure.subplots()
        sns.boxplot(ax=ax, x="day", y="total_bill", data=df, width=0.2, whis=10)
        ax.set_title(title)
        lay = QtWidgets.QVBoxLayout(widget)
        lay.addWidget(canvas)
        canvas.draw()
        return canvas


if __name__ == "__main__":
    app = QtWidgets.QApplication([])
    w = MainWindow()
    w.show()
    app.exec_()