FigureCanvasTkAgg无法正确嵌入matplotlib图

Question

我正在使用tkinter将一些matplotlib图集成到GUI中。它可以成功绘制图形，但是会在第0行和第1行之间创建多余的空间，并用一堆像素填充它。我似乎无法弄清楚哪里出了问题...我相信这里是相关的代码。我还附上了该问题的屏幕截图。

from tkinter import *
from tkinter import ttk
import numpy as np

import matplotlib
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2TkAgg
from matplotlib.figure import Figure

def budget_plot(BF, tags, mark):
    '''
    Plots the total amount spent per month of the tags passed to this function
    '''

    x_axis_labels = BF.months()

    y_axis = list()

    for tag in tags:
        temp = list()
        for month in x_axis_labels:
            temp.append(tag_sum(BF, tag)[month])

        y_axis.append(temp) 

    # indices of the x_ticks, to be used for labeling
    og_ind = np.arange(len(x_axis_labels))

    fig = Figure()
    a = fig.add_subplot(111)

    for i in range(len(y_axis)):

        if mark == 'dot':
            a.plot(og_ind, y_axis[i], 'o', markersize = 12, label=tags[i])
        else:
            a.plot(og_ind, y_axis[i], markersize = 13, label=tags[i])

    a.set_xlabel("Month")
    a.set_xticks(og_ind)
    a.set_xticklabels(x_axis_labels)

    a.set_ylabel("Cost [$]")

    a.set_title("Total Cost / Month")
    a.legend()

    return fig

class FinanceApp(Tk):

    def __init__(self, *args, **kwargs):

        Tk.__init__(self, *args, **kwargs)

        container = ttk.Frame(self)
        container.grid(row=0, column=0)
        container.rowconfigure(0, weight=1)
        container.columnconfigure(0, weight=1)

        # contains all of the pages that can be called.
        # keys -> class of a page
        # values -> the frames of that page with all of its widgets and attributes
        self.frames = dict()

        for F in (StartPage, TagsPageOne, TagsPageTwo, TagsPageThree, DifPageOne):
            # container is the "mother" frame, self is the controller (i.e. the root (Tk) in this case)
            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row=0, column=0, sticky="NSEW")

        self.show_frame(StartPage)

    def show_frame(self, cont):
        # cont -> class of a page

        # call the frame that is associated with the page (class) then raise it to the foreground
        frame = self.frames[cont]
        frame.tkraise()

class TagsPageThree(ttk.Frame):

    def __init__(self, parent, controller):

        ttk.Frame.__init__(self, parent)

        button_home = ttk.Button(self, text = "Start Page", command = lambda: controller.show_frame(StartPage))
        button_home.grid(row=0, column=0, sticky="NSEW")
        button_home.rowconfigure(0, weight=1)
        button_home.columnconfigure(0, weight=1)

        fig = budget_plot(file, ['Grocery'], 'line')

        canvas = FigureCanvasTkAgg(fig, self)
        canvas.draw()
        canvas.get_tk_widget().grid(row=1, column=0)
        canvas._tkcanvas.grid(row=1, column=0)